Environmental Monitors/BioIndicators - Biodiversity for a Livable Climate

Featured Creature: Prickly Pear Cactus

What plant thrives in the harshest landscapes, conserving water like a desert camel, and produces a sweet yet spiky fruit enjoyed for centuries? The Prickly Pear Cactus!

When I’m in the south of France, nothing makes me happier than spending the day by the ocean, taking in the salty breeze and strolling along the littoral. After a long afternoon on the beach, as I make my way home, I always notice prickly pear cacti scattered throughout the local fauna.

Prickly pear cacti are everywhere in the south of France, where I’m from. My mom, who grew up in Corsica, used to tell me stories about how she’d collect and eat the fruit as a kid. So, naturally, last summer, when I spotted some growing along the path home from the beach, I figured—why not try one myself?

Big mistake.

Without gloves (rookie move), I grabbed one with my bare hands. The next 20 minutes were spent with my friends painstakingly plucking hundreds of tiny, nearly invisible needles out of my fingertips. The pain wasn’t unbearable, but watching my hands transform into a pincushion was… unsettling. And to top it all off? The fruit wasn’t even ripe.

For the longest time, I just assumed prickly pears were native to the Mediterranean. They grow everywhere, you can buy them at local markets, and my mom spoke about them like they were an age-old Corsican tradition. But a few weeks ago, while researching cochineal bugs (parasitic insects that live on prickly pear cacti), I discovered something surprising—prickly pears aren’t native to the south of France at all. They actually originate from Central and South America, and were introduced to the Mediterranean from the Americas centuries ago. They’ve since become naturalized.

Curious to learn more, I dove into the biology of prickly pears—and it turns out, these cacti are far more than just a tasty (and slightly dangerous) snack. Their survival strategies, adaptations, and ecological impact make them one of the most fascinating plants out there.

Prickly Pear Cactus Fruit
Credit: Maciej Cisowski via Pexels

Prickly pear cacti belong to the Cactaceae family, and they’re absolute survivors. In spring and summer, they produce vibrant flowers that bloom directly on their paddles, eventually transforming into edible berries covered in sneaky little thorns (trust me, I learned that the hard way).

These cacti thrive in drylands but adapt surprisingly well to different climates. They prefer warm summers, cool dry winters, and temperatures above -5°C (23°F).Their ability to store water efficiently and withstand long dry periods has earned them the nickname ‘the camel of the plant world.’ They can lose up to 80-90% of their total water content and still bounce back, an adaptation that allows them to endure long periods of drought.

They are designed to make the most of their access to water whenever they get the chance. The cactus can develop different types of roots depending on what they need to survive, making them masters of adaptation. One of their coolest tricks? “Rain roots.” These special roots pop up within hours of light rainfall to soak up water—then vanish once the soil dries out.

And then there are their infamous spines. Prickly pears have two kinds: large protective spines and tiny, hair-like glochids. The glochids are the real troublemakers—easily dislodged, nearly invisible, and an absolute nightmare to remove if they get stuck in your skin. (Again, learned this the hard way.)

Nopal (Cactus Pads) – A Nutrient Powerhouse

The term “nopal” refers to both the prickly pear cactus and its pads. It originates from the Nahuatl word nohpalli, which specifically describes the plant’s flat, fleshy segments.

These pads are highly nutritious and well-suited for human consumption, packed with essential vitamins and minerals. They are especially rich in calcium, making them an excellent dietary alternative for populations with high rates of lactose intolerance, such as in India.

Beyond calcium, nopales also provide amino acids and protein, offering a valuable plant-based protein source. They are rich in fiber, vitamins, and minerals, making their nutritional profile comparable to fruits like apples and oranges, explaining their long-standing role in traditional cuisine. From soups and stews to salads and marmalades, they are a versatile ingredient enjoyed in a variety of dishes

Ever wondered how to clean and grill a prickly pear pad at home?

The Fruit – Sweet & Versatile

Prickly pears produce colorful, juicy fruits called tunas, which range in color from white and yellow to deep red and orange as they ripen. Their flavor is often described as a mix between watermelon and berries, while others compare it to pomegranate. Either way, they make for a delicious and refreshing snack.

But before you take a bite, be sure to peel them carefully. If you don’t remove the outer layer properly, you might end up with tiny spines lodged in your lips, tongue, and throat (which is about as fun as it sounds). Once cleaned, the fruit is used in jams, juices, and is even pickled!

Credit: Emilio Sánchez Hernández via Pexels

Prickly pear cacti produce stunning flowers that attract a variety of pollinators, particularly bees. Some specialist pollinators have evolved to depend exclusively on prickly pear flowers as their sole pollen source, highlighting an amazing co-evolutionary relationship. One fascinating example is a variety that has evolved to be pollinated exclusively by hummingbirds, demonstrating the plant’s remarkable ecological flexibility.

If you’d like to see this incredible interaction for yourself, check out the following footage of a hummingbird feeding on a prickly pear flower. Though the video quality is low, the enthusiasm of the couple filming it makes up for it! 🙂

Another fascinating feature of prickly pear flowers are their thermotactic anthers. Okay so yeah, that’s a bit of a mouthful. Basically, the part of the flower responsible for producing pollen, the anthers, have a unique ability to respond to temperature changes—releasing pollen only when conditions are just right for pollination. Prickly pear flowers achieve this through movement; the anthers physically curl over to deposit pollen directly onto visiting pollinators.

You can even see this in action yourself! Try gently tapping an open flower, and watch as it instinctively delivers its pollen like a built-in pollen delivery system.

Once pollinated, the flowers transform into fruit, which then serve as an essential food source for birds and small mammals. These animals help disperse the seeds, allowing new cacti to grow in different areas. But prickly pears don’t just rely on seeds for reproduction, they also have an incredible ability to clone themselves. If a pad breaks off and lands in the right conditions, it can root itself and grow into an entirely new cactus. Talk about resilience!

Like most cacti, prickly pears are tough survivors, thriving even in degraded landscapes. But they go a step further, not just enduring harsh conditions, but actively helping to restore them. The plant’s roots act as natural barriers, preventing erosion, locking in moisture, and enriching the soil with organic matter. Studies show that areas dense with prickly pears experience significantly less soil degradation, proving their role in restoring fragile land.

They also improve soil structure, making it lighter and more fertile, which boosts microbial activity and essential nutrients. They act as natural detoxifiers, absorbing pollutants like heavy metals and petroleum-based toxins and offering an eco-friendly way to restore contaminated soils.

Roots of the prickly pear cactus.
Credit: Homrani Bakali, Abdelmonaim, et. al, 2016

A Tale of Two Ecosystems

Prickly pear plantations are powerful carbon sinks, pulling CO₂ from the air and storing it in the soil. In fact, research shows that prickly pear cultivations in Mexico sequester carbon at rates comparable to forests. A major factor? The cactus stimulates microbial activity in the soil, a key driver of carbon storage.

When farmed sustainably, the CO₂ prickly pears absorb offset the greenhouse gases emitted during cultivation.

Prickly pear cacti have immense capability for land restoration and carbon sequestration, but this potential varies dramatically depending on how they are introduced and managed, and where. In some regions, like Ethiopia, they serve as a lifeline for communities facing desertification. In others, like South Africa, they’ve become invasive, disrupting native ecosystems.

By exploring these two contrasting case studies, we can see how the same plant can either heal or harm the land—and why responsible management is key.

Tigray, Ethiopia: A Natural Fit for Harsh Climates

In Ethiopia, where over half the land experiences water shortages, the prickly pear cactus has become indispensable since its introduction in the 19th century. Arid lands are notorious for unpredictable rainfall, prolonged droughts, and poor soils. But the prickly pear cactus defies these challenges. Requiring minimal water, it provides a reliable food source for both humans and animals, making it an essential crop for small-scale farmers in dry regions.

Prickly pear pads are a crucial livestock feed during droughts, providing moisture and nutrients when other forage is scarce. While it cannot be used as the sole source of nutrition for most ruminants, it’s definitely a necessary supplement in times of drought.

Additionally, the plant’s dense growth creates natural barriers, curbing overgrazing and helping native vegetation recover.

As a food source, prickly pear can be used to supplement human diet. The cactus is an alternative to water-intensive cereals like wheat and barley. With higher biomass yields and significantly lower water requirements, it offers a sustainable solution to food security in drought-prone areas.

Unfortunately, prickly pear cultivation in Ethiopia is under threat from invasive cochineal infestations. These cochineal insects, originally used for dye production, were later introduced outside their native range, where they’ve become agricultural pests, devastating cactus populations.

A cactus infested by cochineal insects
Credit: tjeerddw (CC-BY-NC)

South Africa: When Prickly Pear Becomes a Problem

While the cactus is a valuable resource in some regions, in others, it becomes an invasive species, altering ecosystems and threatening native plants.

In South Africa, prickly pears were introduced by European settlers, but without natural predators to control them, they spread aggressively. Today, they dominate large areas, outcompeting native vegetation and consuming scarce resources like water and soil nutrients. Their dense growth also creates impenetrable thickets that hinder livestock grazing and disrupt local ecosystems.

To control its spread, South Africa turned to biological solutions, ironically using the same cochineal insect that threatens Ethiopia’s prickly pear. In South Africa, cochineal insects have been highly effective at curbing cactus overgrowth, selectively feeding on the invasive species and allowing native plants to recover.

This dual role of the prickly pear cactus—as both a valuable resource and a potential ecological threat—highlights the importance of responsible management. Striking a balance between conservation and cultivation is key to harnessing the plant’s benefits while preventing unintended environmental consequences.

Innovative Uses: From Energy to Eco-Friendly Materials

The prickly pear’s resilience extends beyond its survival in harsh environments—it’s also fueling innovation in sustainability. Scientists and entrepreneurs are finding new ways to harness this plant’s potential, from renewable energy to eco-friendly materials.

In the search for cleaner energy sources, prickly pear biomass is being used to produce biogas and bioethanol, offering a renewable alternative to fossil fuels. Unlike resource-intensive crops, the cactus thrives with minimal water, making it a low-impact solution for sustainable energy. Meanwhile, its juice is being explored as a base for biodegradable plastics. Unlike corn-based bioplastics, which require significant land and water resources, cactus-based plastics are more sustainable and continue growing after harvesting, reducing environmental strain.

Cactus leather, developed by companies like Desserto, provides a sustainable alternative to synthetic and animal-based materials. Unlike traditional vegan leather, which often contains petroleum-based plastics, cactus leather is biodegradable, water-efficient, and durable. As more industries embrace the potential of this remarkable plant, the prickly pear is proving that sustainability and innovation can go hand in hand.

From nourishing communities to restoring degraded land, and generating clean energy, the prickly pear is far more than just a desert plant—it’s a symbol of resilience, innovation, and sustainability. However, its impact depends on careful management. Whether cultivated as a food source or controlled as an invasive species, striking the right balance is key to unlocking its full potential.

And if this article has inspired you to try a prickly pear fruit for yourself, please stick to the store-bought varieties. Unlike wild varieties, cultivated prickly pears are often spineless, making them easier (and safer) to eat. Plus, it would give me, the author, peace of mind knowing that no one has to suffer the same fate I did when I ended up with a hand full of spines after an ill-fated foraging attempt.

Lakhena Park holds degrees in Public Policy and Human Rights Law but has recently shifted her focus toward sustainability, ecosystem restoration, and regenerative agriculture. Passionate about reshaping food systems, she explores how agroecology and land management practices can restore biodiversity, improve soil health, and build resilient communities. She is currently preparing to pursue a Permaculture Design Certificate (PDC) to deepen her understanding of regenerative practices. Fun fact: Pigs are her favorite farm animal—smart, playful, and excellent at turning soil, they embody everything she loves about regenerative farming.

Sources and Further Reading

Featured Creature: Sloth

What creature used to live on the ground but now hangs in trees, has hair that grows in the opposite direction than most mammals, and turns green because of the algae that thrives in their fur?

The Sloth! (Folivora)

Hoffman’s Two-toed Sloth, *Choloepus hoffmanni*
(Image Credit: Andrae Scholz via iNaturalist (CC-BY-NC))

Would you be surprised if I told you that sloths aren’t lazy, but slow and careful?

Sloths have been labeled as some of the laziest animals due to their slow movements and the (unfair and misguided) assumption that they sleep all day. This belief isn’t helped by the fact that the word sloth literally means “laziness,” as does its common name in many other languages. But as we’ll learn, there’s a lot more to this creature than meets the eye, and their chill, methodical nature is actually a quite ingenious survival mechanism.

The six surviving species of sloths are categorized into two groups: Bradypus, the three-toed sloths, and Choloepus, the two-toed sloths. Even with this naming, all sloths have three toes on their back limbs – whereas two-toed sloths only have two digits on their front limbs. Both groups descend from ancestors that were mostly terrestrial (meaning they lived on the ground) that existed about 28 million years ago. Some of them reached sizes rivaling those of elephants! The sizes of modern sloths vary, with three-toed sloths typically ranging from 60-80 cm in length (24-31 inches) and weighing between 3.6-7.7 kg (8-17 lbs), while two-toed sloths can be slightly larger, particularly in weight.

Found in the tropical rainforests of Central and South America, you can identify them by their rounded heads, tiny ears, and a facial structure that makes them look like they’re always smiling. They have stubby tails and long limbs ending in curved claws that, historically used for digging, now work with specialized tendons and a grip strength that is twice as strong as a humans to climb tree trunks and hang upside down from branches effortlessly. It is believed that over time, sloths evolved into a suspensory lifestyle to have easy access to plentiful food (mainly leaves), stay safe from predators (like jaguars and ocelots), and conserve energy.

Leafy Lunches

Sloths have a very low metabolism, meaning their bodies take quite a while to turn food into energy, thus the characteristically sluggish pace. Sloths move at about 4 yards per minute, and in an entire day, they may cover only around 120 feet, which is less than half the length of a football field. These languid movements are the reason why sloths can survive on a relatively low-energy diet, like leaves. While three-toed sloths are almost entirely herbivorous, two-toed sloths have an omnivorous diet that includes insects, fruits, and small lizards.

Even though leaves are the main food source for sloths, they provide very little nutrients and don’t digest easily. These lethargic tree-dwellers have large, slow-acting, multi-chambered stomachs that work for weeks to break down tough leaves. In fact, up to two thirds of a well-fed sloth’s body weight consists of the contents of its stomach. What other animals can digest in hours takes sloths days or weeks to process! Due to their slow digestion, sloths descend every week or so to defecate on the ground. Why exactly they do this is still a mystery to scientists, especially because sloths are at much more risk to predators on the ground.

Did you know that baby sloths learn what to eat by licking the lips of their mother?

Sloths, Moths, and Little Green Friends

Perhaps one of the most fascinating things about our slow-moving friends is what lives in their fur. Believe it or not, it’s a miniature world! Acting as a mobile home for a variety of different insect, fungi, and microbial species, sloths are, in fact, thriving ecosystems. But first, let’s set the scene.

Sloth fur grows in the opposite direction than it does on other animals. Normally, hair will grow towards the arms and legs, but because sloths spend so much of their lives upside down in the canopy with their limbs above their bodies (eating, sleeping, even giving birth hanging upside down), their fur grows away from their extremities and towards their bodies, giving them protection from the elements.

The layered and grooved structure of sloths’ shaggy coat is the perfect environment to host many species of commensal beetles, mites, moths, fungi, as well as a symbiotic green algae. While the sloths don’t directly consume and gain nutrients from the algae (legend held for many years that sloths were so lazy, they’d rather eat the algae off their back than search for food), its presence helps protect the sloths from predators by aiding in their camouflage, hiding them from predators like harpy eagles.

A Slow but Important Presence in the Rainforest

Sloths are an integral part of tropical rainforest ecosystems. They regulate plant growth through their consumption of leaves, provide a unique habitat for smaller organisms like algae and moths in their fur, and contribute to nutrient cycling by depositing their feces on the forest floor, dispersing seeds and fertilizing new plant growth.

Some species of sloths are at risk because of deforestation, contact with electrical lines, and poaching and animal trafficking. The health of these creatures is wholly dependent on the health of the tropical rainforest. If their habitat begins to deteriorate, sloths are forced to live elsewhere in places that cannot support healthy populations.

Luckily, The World Wildlife Fund (WWF) works with communities, governments, and organizations to encourage sustainable forestry, and collaborates to expand areas of forests under responsible management. WWF has worked with the Brazilian government since 2003 on the Amazon Region Protected Areas (ARPA) initiative, helping it become one of the largest conservation projects in the world. Not to mention, The Sloth Institute of Costa Rica is known for caring, rehabilitating, and releasing sloths back into the wild.

Northern Atlantic Forest Three-toed Sloth, *Bradypus variegatus*
(Image Credit: Kevin Araujo via iNaturalist (CC-BY-NC))

More than meets the eye

While sloths are well-known for their slow-moving pace and are labeled as lazy, to believe that that is the only notable thing about them is largely inaccurate. Similar to how judging a person based on one aspect of their personality is not an accurate judgment of their character, judging sloths based on their sluggishness is not an accurate judgment of sloths as creatures. It overlooks how they’ve adapted from life on the ground to life in the trees, how they use their muscles and long claws to hang upside down and save a ton of energy, their role as ecosystem engineers, how they create habitats for other organisms, and how they help maintain the health of the forest.

So the next time we come across a creature – whether in the wild or at a sanctuary – we might ask, “What else can this creature do?”

Abigail Gipson is an environmental advocate with a bachelor’s degree in humanitarian studies from Fordham University. Working to protect the natural world and its inhabitants, Abigail is specifically interested in environmental protection, ecosystem-based adaptation, and the intersection of climate change with human rights and animal welfare. She loves autumn, reading, and gardening.

Sources and Further Reading:

Featured Creature: Japanese Knotweed

With leaves shaped like a spade, what plant
is known to invade and refuses to fade?

The Japanese knotweed (Reynoutria japonica)

Japanese knotweed flowers (Cbaile19 via Wikimedia Commons)

On a warm spring afternoon, my friend and I explored a creek off the Mill River, in Northampton Massachusetts. Thick green bushes lined the banks, making it difficult to reach the water’s edge. As we scoped for a route through, my friend pulled on a nearby branch, inspecting its leaf.

“Japanese Knotweed,” she identified, grasping the plant at the thick part of its stem and straining to pull it up . “This was my whole summer.”

She’d worked on a farm the previous summer and spent countless hours eradicating weeds, which, as it turned out, were mostly Japanese knotweed.

I too am familiar with knotweed. As a child, I mistook Japanese knotweed’s hollow stems for bamboo, often wielding them as makeshift swords. At the time, I thought of the plant as little more than a plaything, unaware of the complex role it was playing in the ecosystem around me.

Photos courtesy Jim Laurie

Where does Japanese knotweed grow?

Japanese knotweed is native to East Asia in Japan, China, and parts of Korea and Taiwan. The plant was introduced to North America in the late nineteenth century, to be used as an ornamental plant. Its introduction, however, had unintended consequences as it invaded wetland, stream corridors, forest edges, and drainage ditches. Japanese knotweed is a herbaceous perennial plant (a non-woody plant that regrows each year from its roots), that can grow to be up to 11 feet tall, with jointed hollow stems resembling that of, yes, bamboo. So you can forgive my childhood ignorance. The stems are bright green and grow nodes which can range in color from red to purple. The knotweed’s spade-shaped leaves grow from these nodes, with a square base and sharp point. They thrive in full sun but can also grow in partial shade, and do well in a variety of soil and moisture conditions. It can often be observed on the banks of rivers, wet depressions, and woodland edges, or in more built environments, including construction sites and roadways.

During the summer, from the nodes of the knotweed bloom small white and pale green flowers. These little flowers are 3 to 4 inches long, and grow in fingerlike clusters, with each cluster holding a couple dozen flowers.

Japanese knotweed (Larrissa Borck via Wikimedia Commons)

While Japanese knotweed is known as an invasive species in many parts of the world, including throughout the United States, in its native range it plays a much different role. There, it exists in balance with local ecosystems, kept in check by native insects, fungi, and herbivores that have evolved alongside it. Instead of forming dense monocultures that crowd out other plants, knotweed grows as part of diverse plant communities, coexisting with a wide variety of species.

Unlike in North America and Europe, where few animals or insects consume it, knotweed supports a variety of wildlife in its natural habitat, and its nectar is enjoyed by bees and butterflies, especially in late summer when other flowers have faded. Insects such as the aphid Aphalara itadori and various beetle species naturally feed on knotweed, limiting its dominance and allowing native plants to thrive alongside it. Some fungi, like Mycosphaerella leaf spot, help regulate its growth, preventing the unchecked spread seen in non-native environments. These interactions ensure that Japanese knotweed remains just one part of a broader ecosystem rather than an overwhelming force.

Ecologically, Japanese knotweed plays an important role in nutrient cycling and soil formation. Its deep, extensive rhizome network helps stabilize slopes prone to erosion in Japan’s more volcanic landscapes, helping to prevent landslides and maintaining soil structure. Additionally, the plant’s decomposition contributes to organic matter in the soil, enriching the surrounding environment.

But when introduced elsewhere, many of these ecological checks and balances are missing, allowing knotweed to spread aggressively and disrupt local biodiversity.

How does it spread?

Japanese knotweed reproduces through both seeds and rhizomes, an underground root-like system which produces shoots of new plants, coming up through the earth. As much as two-thirds of the plant’s biomass is stored in this network.

Seeds of the Japanese knotweed (Famartin via Wikimedia Commons )

The knotweed can be found around the world, far from home. It was introduced to the United Kingdom in 1825 and has since spread across Europe. The majority of Japanese knotweed populations in Europe descend from a single female genotype, though hybridization with related species has introduced some genetic variation. This female genotype is able to receive pollen from a close relative, called the giant knotweed. The combination of these two plants produces a hybrid known as the Bohemian knotweed, which is also spreading across Europe.

In North America, however, the Japanese knotweed reproduces differently than its European counterpart. Even though the European female clone is widely dispersed around the United States, this clone is not the only genotype present. Populations of both male and female Japanese knotweed have been identified across America. The female Japanese knotweed does not produce pollen and primarily spreads through those rhizomes, though it can also reproduce via seeds when pollinated by a related species. Male Japanese knotweed, on the other hand, do produce pollen, as well as occasionally producing seeds.

Impact

Japanese knotweed grows in thick clusters, emerging during early spring time and growing quickly and aggressively. This dense stand of plants crowds out native vegetation, depriving them of resources needed for reproduction and survival.

Japanese knotweed by the water (Dominique Remaud viaWikimedia Commons)

Japanese knotweed thrives in moist, shaded environments. On stream banks, it outcompetes native grasses and shrubs, reducing biodiversity. This lack of diversity along the bank causes instability, and makes it more likely that the soil will shear off during flooding, increasing the amount of sediment deposited into the water. This erosion sends soil and Japanese knotweed seeds into the creek, allowing the plant to spread downstream and further destabilizing the stream bank.

Foraging Japanese knotweed

The young, spring shoots of Japanese knotweed are not only edible, but also delicious! The plant has a tart, slightly sweet taste, similar to that of rhubarb. It can be turned into a jam, put in salads or a stir fry, and used as a crunchy addition to sushi. Where it is native in East Asia, knotweed has been used in traditional medicine for hundreds of years. Owing to the plant’s invasive nature, practicing responsible foraging is crucial to avoid accidentally spreading the knotweed populations. In order to properly dispose of the leftover plant matter, it must be boiled, burned, or thoroughly dried out before discarding in order to ensure that no knotweed is spread. Foraging and eating Japanese knotweed can be a way to help control the plant, through the repeated cutting of the stems. The following video shows a recipe for homemade Japanese knotweed pickles!

Managing knotweed

Due to its dense clusters and deep root system, once established, Japanese knotweed is incredibly difficult to remove. Manually, populations can be managed through repeated cutting, though complete removal of rhizomes is extremely difficult and can sometimes lead to further spread of the knotweed. When it comes to cutting, the stems of the plant must be cut three separate times during the growing season in order for this to be an effective treatment. In terms of digging up the roots, this can be very labor intensive, and the process of digging Japanese knotweed can unintentionally cause the spread of rhizome fragments, which can result in even more Japanese knotweed on your hands!

Japanese knotweed’s spade-shaped leaf (Flocci Nivis via Wikimedia Commons)

Through dedicated work, such as that of my friend who spent three months eradicating Japanese knotweed on her farm, the populations and impacts of the plant, when invasive, can be mitigated. With a little time and effort, you can help control knotweed in your own backyard…and maybe even harvest some for dinner.

Helena is a student at Smith College pursuing psychology, education, and environmental studies. She is particularly interested in conversation psychology and the reciprocal relationship between people and nature. Helena is passionate about understanding how communities are impacted by climate change and what motivates people towards environmental action. In her free time, she loves to crochet, garden, drink tea, and tend to her houseplants.

Sources and Further Reading:

Featured Creature: Cicada

What insect spends years hidden underground, preparing for a brief but spectacular emergence into the sunlight, filling the air with the deafening, iconic song of summer?

The cicada (Cicadoidea)!

Sub Alpine Green Cicada (Image Credit: Julie via iNaturalist)

Every time I return to the south of France, there’s one sound that immediately signals to me that summer has arrived—the unmistakable hum of cicadas. Their chorus, loud and unrelenting, fills the air in the warm Mediterranean heat and acts as a personal cue to pause, take a breath, and unwind. For me, it’s not just the start of summer; it’s the sound of nostalgia, the reminder of countless days spent hiking through the pine forests, picnicking under the shade of olive trees, or simply soaking in peaceful serenity at the beach. The cicadas’ song is always complemented by the sweet, earthy smell of ripening figs. It’s a sensory symphony that epitomizes the region’s charm.

These moments, marked by the rhythmic buzz of cicadas, offer a unique connection to nature—one that I’ve come to cherish as a deeply rooted part of my experience in the region. The cicadas’ song is a call to slow down, reconnect, and embrace the simple beauty of life in the south of France.

As much as these personal experiences have shaped my connection to cicadas, there’s so much more to learn about these fascinating creatures. From their complex life cycles to the essential roles they play in ecosystems around the world, cicadas are much more than the soundtrack of summer.

The Backstory

If the name “cicada” doesn’t quite ring a bell, you might recognize it from Animal Crossing. It’s a common insect that players can encounter in the game.

Cicadas are the loudest insect species in the world, known for their buzzing and clicking noises, typically sung during the day. This song, produced by males to attract females, is a highly specialized mating call. Each species of cicada has its own unique variation, which is genetically inherited rather than learned, unlike the calls of other animals such as birds. Some cicada species, like the double drummer, even group together to amplify their calls, deterring predatory birds by overwhelming them with noise. Others adapt by singing at dusk, avoiding the attention of daytime predators.

If you’re curious about the fascinating science behind how cicadas create their iconic sound and want to dive deeper into their unique anatomy, I highly recommend checking out the following video. It’s a captivating look at how these incredible insects make their music!

But there’s more to cicadas than their songs. If you’ve ever tried to catch one, you might have discovered their quirky behavior firsthand—cicadas pee when they fly! This “cicada rain” is simply their way of excreting excess liquid after consuming large amounts of plant sap. While it’s harmless, it’s something to keep in mind if you’re ever under a tree full of buzzing cicadas—or reaching out to grab one!

With more than 3,000 species worldwide, cicadas are primarily found in temperate and tropical climates, avoiding regions with extreme cold. Their life cycle consists of three stages: egg, nymph, and adult. After hatching, nymphs burrow underground and feed on plant root sap for years before emerging, molting, and transforming into adults.

Watching a cicada emerge from its nymphal shell is like witnessing a miniature metamorphosis in real-time—its delicate wings unfurling as it prepares to take flight. If you’ve never seen this magical process, here’s a fascinating video that brings it to life.

While most species are annual cicadas, emerging every year, some, like the periodical cicadas of North America, emerge every 13 or 17 years. These synchronized groups are referred to as “broods.” A brood consists of all the cicadas of the same lifecycle group that emerge in a specific year within a particular geographical area. This classification system helps scientists and enthusiasts track and study the various populations of periodical cicadas.

These mass events, involving millions of cicadas, are a marvel of nature and the unique cycle remains a topic of scientific curiosity. In exceptionally rare cases, two different broods can emerge simultaneously, creating a spectacle of overlapping generations. This video explains more about these extraordinary dual emergence events and why they capture the fascination of entomologists and nature enthusiasts alike.

Showstoppers: Stunning Species from Around the World

Across the globe, these fascinating insects showcase an incredible range of colors, patterns, and sizes, rivaling even the most vibrant creatures of the animal kingdom. Here’s a look at some standout species that prove cicadas are as much visual marvels as they are auditory icons:

**Tacua speciosa**: Native to Southeast Asia, *Tacua speciosa* is among the largest cicadas, boasting a black body with a striking yellow or chartreuse pronotal collar and cyan or yellow tergites and shimmering blue-green wings. Found in Southeast Asia, this giant cicada commands attention not just with its size but with its bold elegance.
(Image Credit: Valentinus-Tikhonov via iNaturalist)

**Zammara Smaragdina**: Found in tropical regions, this species stuns with its bright turquoise coloration, a rare hue in the insect world that gives it a truly jewel-like appearance.
(Image Credit: Benoît Guillon via iNaturalist)

**Salvazana mirabilis imperialis**: This species, found in Cambodia, China, Laos, Thailand, and Vietnam, displays an amazing blend of greens and reds on their wings.
(Image Credit: xtbg-eec via iNaturalist)

Cicadas vs. Locusts: Clearing Up the Confusion

Cicadas are often mistaken for locusts, a confusion that dates back to early European colonists who likened the sudden mass emergence of cicadas to the biblical plagues of locusts. However, cicadas and locusts are very different insects with distinct behaviors and ecological impacts.

Locusts, a type of grasshopper, are infamous for forming destructive swarms that can devastate crops and vegetation, causing severe agricultural damage. In contrast, cicadas do not consume foliage in a way that harms plants or crops. While their synchronized emergences can be dramatic, cicadas are not considered pests and pose no threat to agriculture.

Cicadas’ Impact: How They Shape the Ecosystem

Cicadas play a crucial role in maintaining ecosystem balance at every stage of their life cycle. During their subterranean nymph stage, they engage in burrowing activities that profoundly impact soil structure and health. By creating tunnels, they aerate the soil, facilitating root respiration and improving water infiltration, which enhances soil moisture distribution. Their burrowing also redistributes nutrients, mixing organic matter and minerals from different soil layers, which boosts soil fertility and supports plant growth.

These tunnels also provide microhabitats for other soil organisms, such as insects, microorganisms, and invertebrates, fostering biodiversity. Upon their emergence, adult cicadas become a vital food source for various predators, such as birds, mammals, and reptiles, boosting the survival and reproduction of these species.

When cicadas die, their decomposing bodies enrich the soil with nutrients, stimulating microbial activity and increasing the diversity of soil microarthropod communities (Microarthropods are like miniature insects such as springtails or soil mites). This nutrient flux improves plant productivity and even impacts the dynamics of woodland ponds and streams, underscoring their importance in nutrient cycling.

Cicadas as Ecological Signals: What They Tell Us About Nature

Cicadas are valuable bioindicators, reflecting the health of their environments. As root feeders, their abundance can tell us a lot about the integrity of root systems and the availability of water and nutrients. Cicadas also require well-structured, uncompacted soil to create their burrows, making their presence an indicator of healthy soil conditions.

The Cicada-MET protocol, which involves counting cicada exuviae (shed skins), offers a standardized method to assess environmental quality. Additionally, acoustic methods to analyze their songs are used to study the impacts of disturbances like wildfires and can guide conservation strategies.

Challenges Facing Cicadas: The Threats to Their Survival

Cicadas face various threats that jeopardize their populations and the ecosystems they support. Habitat loss due to urbanization is a significant challenge, as forests and grasslands are replaced with buildings and infrastructure, reducing the availability of suitable

environments for their life cycles. Planting native trees, preserving green spaces, and advocating for wildlife-friendly urban planning are simple but effective ways to help restore their habitats. For example, oak, pine, and olive trees in Mediterranean areas, or sycamore and dogwood in North America, are ideal choices. Climate change is another major threat, particularly in regions like Provence, where extreme heat waves can suppress cicada singing and disrupt mating behaviors, potentially forcing them to migrate to cooler areas, altering both new ecosystems and those they leave behind.. Additionally, some cicada species are vulnerable to invasive pathogens, such as fungi like Massospora cicadina, which manipulate their behavior and spread infections. While this fungus predominantly affects periodical cicadas, similar threats could arise for other species. If you have the opportunity, I would recommend participating in citizen science projects to report sightings of infected cicadas and track population health.

A Month of Delight

Cicadas have a way of sparking curiosity and creativity in those who encounter them. Whether it’s collecting their delicate, shed exoskeletons to study, transforming them into art, or pausing to listen to their summer chorus, these insects invite us to engage more deeply with the natural world. By paying closer attention to creatures like cicada’s, we can gain a greater appreciation for their fascinating life cycles, and develop a stronger connection to the ecosystem that sustains them.

Naturalist Jean-Henri Fabre once said, “Four years of hard work in the darkness, and a month of delight in the sun––such is the Cicada’s life, We must not blame him for the noisy triumph of his song.” By understanding and appreciating these extraordinary creatures, we can ensure their songs—and the inspiration they bring—continue to resonate for generations to come.

Lakhena

Sources and Further Reading:

Featured Creature: Kingfisher

What creature often looks blue, but isn’t, is found on every continent but Antarctica, and inspired a train’s design?

Kingfishers! (Alcedinidae)

Patagonian Ringed Kingfisher, *Megaceryle torquata ssp. stellata*
(Image Credit: Amelia Ryan via iNaturalist)

Kingfishers are kind of like snowflakes. They both float and fly through the air, and no two are really alike. It’s what I love so much about them. Each kingfisher presents characteristics unique to their own lifestyle. They make me think of people. Like kingfishers, we live almost everywhere on Earth and we’ve all adapted a little differently to our diverse environments. I hope as you get to know the kingfisher, you’ll start to feel a small connection to these birds as I have.

Kingfishers are bright, colorful birds with small bodies, large heads, and long bills. They’re highly adaptable to different climates and environmental conditions, making them present in a variety of habitats worldwide. Many call wetland environments like rivers, lakes, marshes, and mangroves home. Now, their name might lead you to think all kingfishers live near these bodies of water, but more than half the world’s species are found in forests, near only calm ponds or small streams. Others live high in mountains, in open woodlands, on tropical coral atolls, or have adapted to human-modified habitats like parks, gardens, and agricultural areas.

Common Kingfisher, *Alcedo atthis* (Image Credit: Alexis Lours via iNaturalist)

Even so, you’re most likely to spot them in the tropical regions of Africa, Asia, and Oceania, but they can also be found in more temperate regions in Europe and the Americas. Some species have large populations and massive geographic ranges, like the Common Kingfisher (Alcedo atthis), pictured above, which resides from Ireland across Europe, North Africa and Asia, as far as the Solomon Islands in the Pacific. Other kingfishers (typically insular species that evolved on islands) have smaller ranges, like the Indigo-banded Kingfisher (Ceyx cyanopectus), which is only found in the Philippines.

Birds of a Feather

Kingfishers are small to medium sized birds averaging about 16-17 cm (a little over 6 inches) in length. They have compact bodies with short necks and legs, stubby tails and small feet, especially in comparison to their large heads and long, pointed bills. While many species are proportioned the same way, some are quite distinct. Paradise Kingfishers (Tanysiptera), which are found in the Maluku Islands and New Guinea like the one pictured below, are known for their long tail streamers. The African Dwarf Kingfisher (Ispidina lecontei) is the world’s smallest kingfisher at just 10 cm (barely 4 inches) long, and is found in Central and West Africa. The largest is the Laughing Kookaburra (Dacelo novaeguineae), coming in at a whopping 41-46 cm (15-18 inches) long, and is native to Australia.

Buff-Breasted Paradise Kingfisher, *Tanysiptera sylvia*
(Image Credit: Peter and Shelly Watts via iNaturalist)

Now, I know what you’re thinking: ‘Wait, are kookaburras and kingfishers the same thing? Sometime. Out of all 118 species, only four go by the name kookaburra: the Laughing Kookaburra (Dacelo novaeguineae), the Blue-winged Kookaburra (Dacelo leachii), the Spangled Kookaburra (Dacelo tyro), and the Rufous-bellied Kookaburra (Dacelo gaudichaud). Native to Australia and New Guinea, the kookaburra are named for their loud and distinctive call that sounds like laughter. Sometimes their cackles can even be mistaken for monkeys!

So, are they as colorful as everyone says?

Yes! If you ask anyone who has seen a kingfisher to describe what it looks like, they will most likely go on and on about its color. Kingfishers are bright and vividly colored in green, blue, red, orange, and white feathers, and depending on the species, can be marked by a single, bold stripe of color. These features all accent the bird’s most recognizable feature, which is the blue plumage on their wings, back, and head. But here’s where things get interesting: Kingfishers don’t actually have any blue pigment in their feathers.

Laughing Kookaburra, *Dacelo novaeguineae* (Image Credit: Angela Quinn via Pixabay)

So, what gives? It’s something called the Tyndall effect. What’s happening is that tiny, microscopic keratin deposits on the birds’ feathers (yes, the same keratin that’s in your hair and nails) scatter light in such a way that short wavelengths of light, like (you guessed it) blue, bounce off the surface while all others are absorbed into the feather.

It sounds a little strange, but you see it every day. It’s why we see the sky as blue, too.

Azure Kingfisher, *Ceyx azureus* (Image Credit: David White via iNaturalist)

Are kingfishers Really Kings of Fishing?

Yes! And no. Kingfisher species are split into three subfamilies based on their feeding habits and habitats: the Tree Kingfishers (Halcyoninae), the River Kingfishers (Alcedininae), and the Water Kingfishers (Cerylinae). Despite their name, many of these birds primarily prefer insects, taking their prey from the air, the foliage, and the ground. They also eat reptiles (like skinks and snakes), amphibians, mollusks, non-insect arthropods (like crabs, spiders, scorpions, centipedes, and millipedes), and even small mammals like mice.

Tree Kingfishers reside in forests and open woodlands, hunting on the ground for small vertebrates and invertebrates. River Kingfishers are more often found eating fish and insects in forest and freshwater habitats. Water Kingfishers, the birds found near lakes, marshes, and other still bodies of water, are the fishing pros, specialize in catching and eating fish, and are actually the smallest subfamily of kingfishers, with only nine species.

New Zealand Sacred Kingfisher, *Todiramphus sanctus* ssp. vagans, eating a crustacean
(Image Credit: Ben Ackerley via iNaturalist)

Because the diets of kingfishers vary, so does the size and shape of their bills. Even though all species have long, dagger-like bills for the purpose of catching and holding prey, those of fishing species are longer and more compressed while ground feeders have shorter and broader bills that help them dig to find prey. The Shovel-billed Kookaburra (Clytoceyx rex) has the most atypical bill because it uses it to plow through the earth looking for lizards, grubs, snails, and earthworms.

Shovel-billed Kookaburra, *(Clytoceyx rex)*
(Image Credit: Mehd Halaouate via iNaturalist)

Can the blue-but-not-really-blue kingfisher get any more interesting?

Oh yes, yes it can. Ready for another physics lesson? Kingfishers have excellent binocular vision, which means they’re able to see with both eyes simultaneously to create a single three-dimensional image, like humans. Not only that, but they can see in color too! But what makes them so adept at catching fish is their capability to compensate for the refraction of light off water.

When light travels from one material into another (in this case, air into water), that light will refract, or bend, because the densities of air and water are different. This makes objects look as though they are slightly displaced when viewed through the water surface. Kingfishers are not only able to compensate for that optical illusion while hunting, but they also can accurately judge the depth of their prey as well.

But, triangulating underwater prey is only half the battle. Then you’ve got to catch it.

Fishing species of kingfishers dive no more than 25 cm (10 inches) into the water, anticipating the movements of their prey up until impact. Again, what happens next differs depending on which kingfisher we’re talking about. Many have translucent nictitating membranes that slide across their eyes just before impact to protect them while maintaining limited vision. Others, like the Pied Kingfisher (Ceryle rudis leucomelanurus), actually have a more robust bony plate that slides out across its eye when it hits the water—giving greater protection while sacrificing vision.

Pied Kingfisher in action

Kingfishers usually hunt from an exposed vantage point, diving rapidly into the water to snatch prey and return to their perch. If the prey is large (or still alive), kingfishers will kill it by beating it against the perch, dislodging and breaking protective spines and bones and removing legs and wings of insects. The Ruddy Kingfisher (Halcyon coromanda) native to south and southeast Asia, removes land snails from their shells by smashing them against stones on the forest floor.

Typically, kingfishers have eyes so dark brown they’re nearly black. In this photograph, however, you can see these Common Kingfishers’ nictitating membranes, most likely activated on land to remove sand or any other debris that may be hindering their vision. Image Credit: misooksun via iNaturalist

Learning from kingfishers

Occupying a place fairly high in their environments’ pecking orders (trophic level) makes kingfishers susceptible to effects of bioaccumulation, or the increasing concentration of pollutants found in living things as you climb the food chain. This phenomenon, coupled with the kingfisher’s sensitivity to toxins, makes the bird a fairly reliable environmental indicator of ecosystem health. If a kingfisher population is strong, that can indicate their habitat is healthy because the small aquatic animals they feed on aren’t intaking poisons or pollutants. When problems are detected in a kingfisher population, it can serve as an early warning system that something more systemic is wrong.

But that’s not the only thing we can, or have learned, from kingfishers. In 1989, Japan was looking for a way to redesign its Shinkansen Bullet Train to make it both faster and quieter. As the train flew through tunnels at 275 km/h, massive amounts of pressure would build up, reigned in by the front of the train and the tunnels’ walls. Upon exiting the tunnels, that pressure would release, sending roaring booms through the homes of those living nearby. Engineer Eiji Nakatsu was not only the project’s lead, but birdwatcher as well. Noting the kingfisher’s ability to plunge into dense water at incredible speeds with hardly a splash, Nakatsu and his team remodeled the front of the train with the bird’s beak in mind. The result not only solved the problem of the boom, but also allowed the train to travel faster while using less energy.

Kingfishers: A Little More Like You Than You Think

In learning about the kingfisher, I saw a little bit of us. We all come from the same family, even if we each do things a little differently. I think for me, this gets to the root of why finding our connections with all living things matters, not just because they give us inspiration to solve human problems or because we depend on them to keep natural systems in balance, but because this is just as much their Earth as ours.

Let’s do our part,

Abigail

Sources and Further Reading:

Featured Creature: Pigeon

What often-overlooked creature is an expert navigator, an impressive postman, and a natural mammographer?

A pigeon!

While the term “pigeon” actually refers to over 300 species of bird of the family Columbidae, the animal is generally characterized by its plump body, head-bobbing strut, and gentle disposition. That, and the fact that they seem to be everywhere. Pigeons have adapted to the majority of habitats on earth, with the most impressive being the urban environment.

Rock pigeons, also known as city pigeons or common pigeons, were first introduced to North America in the 1600s, from Europe. Since then, they have come to inhabit nearly every city across the Americas.

Historical records in Mesopotamia and ancient Egypt suggest that pigeons were first domesticated around 5,000 years ago, making it nearly impossible to discern their original, wild range. Today, wild pigeons make homes of rocky cliffs or in caves, while their feral cousins nest on building ledges.

With some of the most powerful flight muscles in the animal kingdom, pigeons are impressive fliers with the ability to take off almost vertically and avoid any in-flight obstacle. This enables them to dwell in even the busiest urban environments.

Lovebirds!

Pigeons are monogamous, mating for life, and typically raise 1 to 2 chicks at a time. Their mating season is May through August in the Northern hemisphere, and co-parenting is key to the nestlings’ success. Dad usually takes the day shift while Mom takes the night watch, alternating incubation duties so the other can hunt for food or hit the McDonald’s drive thru.

In the first four or five days after hatching, the chicks are fed “pigeon milk,” a unique secretion of a portion of the parents’ digestive system called the “crop.” This milky liquid is rich in nutrients and closely resembles that of mammals’ milk. Crop milk production is a hormonal response that begins a few days before the eggs hatch. When the chicks are around 10 days old, the milk-producing cells return to their normal dormancy and hatchlings can ease into a normal pigeon diet. (This process isn’t unique to pigeons; flamingoes and some species of penguin also produce a milk-like substance for their hatchlings.) Four to six weeks later, pigeon chicks are semi-independent, freeing the mated pair to start another brood. A couple of common pigeons can raise up to 12 chicks (six pairs of eggs) in a single mating season.

Both Beauty and Brains

Due to both natural selection and human breeding, there are now over 300 species of pigeon cooing across the globe. They are all descendents of the humble rock pigeon.

Charles Darwin, a pigeon breeder, marveled at the beauty of evolution at work in the range of appearance and genetic expression in pigeons, calling it an analogy of what happens in nature. Many species of wild pigeon have developed flamboyant colors and crests that rival that of anyone’s favorite bird. Check out the photos below for some beautiful displays!

Crested Pigeon (Image by schneeknirschen on Pixabay)

Pigeon in Budapest (Image by Charles on Pixabay)

Doves are biologically identical to common pigeons
(Image by StockSnap on Pixabay)

Pigeons are more than just looks, though. They’ve managed to take on a variety of human tasks with ease, often outperforming their human and technological counterparts. Pigeons have been carrying mail for centuries, back to ancient Roman times, and can deliver mail at speeds of up to 90 miles per hour (their average flight speed being 50-60 mph). They were even employed as military spies, with 95% of pigeons completing their missions and returning photographs of enemy operations to their side in WWI. The key to their impressive performance is their ability to tap into earth’s magnetic field.

They can also read the position of the sun, and have a keen sense of sight and smell. Their acute eyesight also makes them, unexpectedly, great mammographers. Pigeons can diagnose breast cancer in human patients with an accuracy on par with human radiologists reviewing the same cases.

So maybe the next time you hear someone refer to pigeons as “sky rats,” take a moment to share about some of the brilliance behind those red eyes.

Humbly,
Ryan

Ryan Pagois is a climate advocate and systems thinker serving as an Associate Director at Built Environment Plus, helping to drive sustainable building solutions in MA. He is passionate about urban ecology, carbon balance, and rewilding cities. He is excited to pursue a Masters of Ecological Design at the Conway School starting this fall, to explore how low-impact urban development can be our greatest climate solution and community resilience tool. He grew up in Minnesota and studied environmental policy and international relations at Boston University.

Sources and Further Reading:
https://www.britannica.com/animal/pigeon
https://www.allaboutbirds.org/guide/Rock_Pigeon/overview#
https://www.nationalgeographic.com/animals/article/pigeons-diversity-doves-photographs
https://www.ovocontrol.com/pigeon-facts-figures
https://www.ovocontrol.com/news-blog/2018/01/how-fast-do-pigeons-reproduce
https://www.spymuseum.org/exhibition-experiences/about-the-collection/collection-highlights/pigeon-camera/
https://www.northumberlandnationalpark.org.uk/pigeon-perfect/
https://www.universityofcalifornia.edu/news/pigeons-can-distinguish-cancerous-breast-tissue-normal
https://www.audubon.org/field-guide/bird/rock-pigeon
https://www.audubon.org/news/pigeon-milk-nutritious-treat-chicks
https://www.nytimes.com/2013/02/05/science/pigeons-a-darwin-favorite-carry-new-clues-to-evolution.html

Featured Creature: Flamingo

What long-legged creatures are known for their beauty, social habits, and fabulous flamboyance?

Flamingos!

Flamingos are among the most recognizable birds in the world. These long-legged wading birds are known for their vibrant pink plumage and distinctive S-shaped necks, and rank among the most iconic inhabitants of wetlands across the globe.

They are known to congregate in large flocks, standing (often perched on one leg) in the shallows of their habitat. Given their unmistakably flashy appearance, it is apt that a group of flamingos is known as a “flamboyance.”

Flamingos boast a slender body, stilt-like legs, and a characteristic downward-bending bill, making them instantly recognizable. Though they are most often depicted as a bright pink, their plumage ranges from a subtle pink to crimson. This hue is actually derived from carotenoid pigments found in their diet of algae, crustaceans, and small invertebrates. So as flamingos’ range and available food sources vary, so too might their color. Interestingly, this same pigment responsible for the flamingo’s iconic pink is also what makes carrots orange and ripened tomatoes red.

Flamingos thrive in saline or alkaline lakes, mudflats, and shallow lagoons, where they feed on algae, invertebrates, larvae, small seeds, and crustaceans like brine shrimp. Their long legs enable them to wade into deeper waters, utilizing their uniquely adapted bills to filter food from the mud and water. In fact, though the term usually calls to mind creatures like oysters or whales, flamingos are also considered “filter feeders” in their behavior and diet.

While most flamingo species are not endangered, habitat loss and human activities pose significant threats to their populations. Conservation initiatives, such as the establishment of protected reserves and the monitoring of wild populations, are crucial for safeguarding these charismatic birds and their habitats. As indicators of environmental health and key feeders in the wetlands, flamingos play a vital role in maintaining the delicate balance of their ecosystems.

Lifestyle and relationships

Flamingos are highly social creatures, forming large flocks that can number in the thousands. They engage in intricate mating displays and rituals, characterized by synchronized movements and vocalizations. Once a couple has chosen to mate, breeding pairs construct simple mud nests, where they raise their offspring, feeding them a specialized “crop milk” produced in their upper digestive tract.

With a lifespan of 20 to 30 years in the wild, and up to 50 years in captivity, flamingos exhibit remarkable longevity. They typically lay a single chalky-white egg, which both parents incubate and care for until hatching. Young flamingos, born with gray downy feathers, gradually develop their iconic pink plumage over time.

Over time, these bright birds form strong social bonds that characterize their lives and behaviors. Remarkably, it has been observed that some flamingos will make friends for decades. Researchers have speculated that the bonds, which are influenced by factors such as personality traits and physical characteristics, may aid survival.

This long lasting affinity has led to comparisons and speculations about different forms of love in the animal kingdom. Though we see lots of courtship, pairing, and even mating for life in different species, friendship is one of those underrated forms of love well worth celebrating. And while these social relationships may indeed help with survival, it also might just be true that life is better with friends by your side.

Feeling the love,

Maya

Maya Dutta is an environmental advocate and ecosystem restorer working to spread understanding on the key role of biodiversity in shaping the climate and the water, carbon, nutrient and energy cycles we rely on. She is passionate about climate change adaptation and mitigation and the ways that community-led ecosystem restoration can fight global climate change while improving the livelihood and equity of human communities. Having grown up in New York City and lived in cities all her life, Maya is interested in creating more natural infrastructure, biodiversity, and access to nature and ecological connection in urban areas.

Sources and Further Reading:
https://animals.sandiegozoo.org/animals/flamingo
https://kids.nationalgeographic.com/animals/birds/facts/flamingo
https://nationalzoo.si.edu/animals/american-flamingo
https://www.audubon.org/birds-of-america/american-flamingo
https://www.nationalgeographic.com/animals/article/flamingos-make-friends-for-life
https://nationalzoo.si.edu/animals/news/why-are-flamingos-pink-and-other-flamingo-facts

Featured Creature: Crow

Carrion crow (Corvus corone) black bird portrait of head and looking at camera. Wildlife in nature. Netherlands

What common bird possesses an uncommon intelligence, including diversified communication, excellent memory, and a talent for mathematics?

The crow!

Crows, members of the Corvus genus, stand out as some of the most intelligent and adaptable birds on the planet. These corvids include over 40 species, such as the American crow, hooded crow, and fish crow, and they inhabit diverse habitats ranging from dense forests to urban landscapes.

Known for their resourcefulness and problem-solving skills, crows have captivated scientists and observers alike with their remarkable behaviors. Crows continue to push the boundaries of how we understand animal intelligence, with recent studies on their tool use, awareness, and relationship to complex concepts gaining them well-deserved recognition and a place in the conservation conversation.

Crows are a fairly common sight in many parts of the world, with recognizable shiny black feathers and a familiar ‘caw.’ They are ground foragers with an incredibly diverse diet, ranging from insects and fruits to small animals and human food scraps. They tend to be associated with scavenging but are true omnivores, and can benefit soils and ecosystems by helping keep insect populations from surging out of balance. In urban settings, they are involved in flock feeding on human food scraps and garbage, and this adaptability to human environments means certain (though not all) species of crow maintain strong population numbers in the face of decreased access to natural habitat.

Communication and Complexity

While the crow ‘caw’ may seem like a simple call recognizable to many people, crow vocalization turns out to be quite differentiated. It has been discovered that among crows, groups form ‘dialects’ based on region. They also possess remarkable vocal mimicry skills, allowing them to imitate the sounds of other birds, animals, and even human speech. All of this allows the crow to engage in communication, social bonding, and strategic goals of deception and resource acquisition.

These crafty corvids possess a level of intelligence comparable to great apes and human children, allowing them to solve complex problems and even make and use tools. For instance, the New Caledonian crow, widely regarded as the most intelligent species among the corvid family, creates hooks and skewers from twigs to extract insects from crevices, showcasing their ingenuity. Researchers have studied crows’ usage of tools and observed that these birds will not only use pre-made tools or create simple combinations of tools in pursuit of their goal, but create multi-part composite tools, a behavior observed in only a few primates.

Famously, Aesop’s fables summarized long ago, “A thirsty crow wanted water from a pitcher, so he filled it with pebbles to raise the water level to drink.” Though the story is thousands of years old, these behaviors are still being studied and producing new insight today.

Image by Thanasis Papazacharias from Pixabay

Some of the most fascinating recent inquiries into crow intelligence have probed crows’ sense of self-awareness, long-term gratification, playfulness, and their understanding of complex concepts. As a math lover, one of my favorites among these is a unique phenomenon – conceptualization of ‘zero’. While many animals are able to perform basic counting, zero is generally a trickier beast, one that was absent from many ancient human civilizations’ numerical systems. However, crows are among the very few animals that grasp this number.

Additionally, crows exhibit impressive memory skills and can recognize individual human faces, reacting differently to perceived threats than to harmless humans. They are even known for ‘holding grudges,’ or conversely, remembering favorable relationships with people for years at a time. The ability to remember and share information within families and flocks may provide them with a significant evolutionary advantage in protecting themselves from harm.

Birds of a Feather Flock Together

In addition to their intelligence and adaptability, crows exhibit fascinating social behaviors. They often engage in cooperative mobbing to fend off predators, perform elaborate aerial displays to attract mates, and maintain strong family bonds by living in cooperative family groups. While adult crows primarily socialize just with their monogamous mate (with whom they pair for life), young crows stay with their parents for the first two years of life, and juvenile crows live in highly social ‘juvenile gangs.’ One theory into crow intelligence suggests that their ingenuity is due to the relatively long period of time young crows spend with their parents and the learning this enables.

Some crows, like American Crows, are also known to flock in large groups in winter months, both foraging for food and roosting together. These roosts can range from a few hundred to up to two million crows, with some roosts forming in the same general area for well over 100 years. Moreover, crows hold “funerals” for deceased members of their community, demonstrating a level of social complexity often overlooked among animals.

Crows will even form bonds with other animals. Crows in the wild have been observed playing with young wolves, and forming mutual attachments with these other social and intelligent creatures. Of course, there are many stories of the relationships humans have forged with individual crows, forming patterns of exchanging food for gifts or receiving trinkets after showing an injured bird care. One charming crow, Tuck, who has spent his life in a bird sanctuary in Tennessee, shares a moving friendship with his primary human caretaker, and has even become a conservation ambassador:

While many human cultures have depicted crows with respect for their ingenuity, recent trends have given crows a bad rap, primarily for the disturbance they cause to crops (hence the need for ‘scarecrows’). Despite their reputation as pests, though, crows play a crucial role in ecosystems as efficient garden helpers and natural pest controllers. They feast on insect pests like caterpillars and beetles, disperse seeds, and maintain a healthy balance in the garden ecosystem. Some crow species face significant challenges to their survival, such as habitat loss, disease, and predation, and crucial conservation efforts are underway to protect endangered species like the Hawaiian Crow through habitat restoration and captive breeding programs.

Crows have been both feared and revered by humans throughout history, often associated with death, darkness, and supernatural powers. The term “murder of crows” reflects their association with death and darkness in folklore, although alternative names like “horde” or “parliament” better capture their intelligent and social nature without perpetuating negative connotations. And many cultures and people have great respect for the clever crow, with whom we have coexisted for thousands of years. Despite their complex relationship with humans, crows continue to fascinate and inspire awe, challenging our limiting notions of animal behavior.

For a deeper dive into crows and the insights they share on animal intelligence, check out this fascinating video and the sources below:

May we continue to learn from our animal kin,

Maya

Sources and Further Reading:
https://www.iflscience.com/crows-once-again-prove-their-intelligence-by-showing-that-they-understand-zero-60069
https://bigthink.com/neuropsych/crows-higher-intelligence/
https://arstechnica.com/science/2023/12/what-happens-in-a-crows-brain-when-it-uses-tools/
https://www.allaboutbirds.org/guide/American_Crow/overview
https://www.trvst.world/biodiversity/crow-facts/
https://www.audubon.org/news/10-fun-facts-about-american-crow
https://www.audubon.org/news/a-funeral-crows
https://www.npr.org/2020/10/23/927088859/crows-are-they-scary-or-just-super-smart

Featured Creature: Zombie Ant Fungus

What creature preys on ants and other insects, invading their bodies, seizing control of their minds, and killing them off to reproduce, all the while inspiring zombie stories that terrify us humans?

Welcome to Zombie Ant Fungus, or Ophiocordyceps Unilateralis!

One of the most amazing things about being in touch with the natural world is the uncontained sense of wonder that infuses us as we learn about the incredible range of biodiversity out there to be discovered. My recent pieces on Mantis Shrimp and Ghost Pipes are good examples of diversity and symbiosis, while this curious creature shows off the parasitic side of interspecies relationships. Ophiocordyceps unilateralis, commonly known as Zombie Ant Fungus, is an insect-pathogenic fungus, discovered by the British naturalist Alfred Russel Wallace in 1859, and currently found mostly in tropical forest ecosystems.

The Zombie Ant Fungus is like no other creature I know; it’s like a runaway horror movie that even ants shall encounter with fear, and try their best to avoid. Its story is intriguing and represents scary stuff. Indeed, this strange creature is featured in two books by M. R. Carey called The Girl with All the Gifts and The Boy on the Bridge, as well as in a video game and show, The Last of Us, which recently wrapped up its first season to critical acclaim. In that feature, humans struggle to survive after an infectious fungus turns us into zombies largely in the style of Ophiocordyceps.

Who knew that such an innocent seeming creature could become so devious and troublesome? Is there anywhere for us to hide? We need not worry. This pathogen can’t transfer to us, or at least to do so would take many millions of years. So I guess we can relax…

There are some major differences between how the fungus is portrayed in shows like The Last of Us and in real life. Cordyceps does not typically infect other hosts through the mouth, and the infected aren’t connected to each other through a network.

Most importantly, the fungus cannot infect humans, because our body temperatures are too high for most of them. Phew! In fact, people have been eating Cordyceps for centuries now without turning into zombies. It’s a traditional Chinese medicine, used to treat kidney disease and other ailments. So let’s set aside these worries, and get back to the reality of these intriguing creatures.

A Sinister Cycle

These fungi live in jungle habitats, such as in tropical forests, where a species of carpenter ant, Camponotus Leonardi, lives in the high canopy and has an extensive network of aerial trails. But sometimes the canopy gaps are too far apart and difficult to cross, so the ants’ trails descend to the forest floor where they are exposed to Zombie Ant Fungus (Ophiocordyceps unilateralis) spores.

The spores attach to these ants’ exoskeletons and break through, invading its host’s body as a parasite. Like other fungi pathogenic to insects in the genus Ophiocordyceps, this fungus targets a specific host species, in this case the carpenter ant. However, this fungus may also parasitize other closely related species of ants or other insects, though these come with lesser degrees of host manipulation and reproductive success. Some of this fungus’ subspecies, such as Ophiocordyceps sinensis, colonizes ghost moth caterpillars instead of carpenter ants and erupts from their head like a unicorn horn.

Check out the sprouting phenomenon taking place in an infected bullet ant:

As in zombie lore, there’s an incubation period where infected ants appear quite perfectly normal and go about their business undetected by the rest of the colony. First, the spore infects the ant and fungal cells start growing inside its body with no notable effects from the outside. But eventually, the infected ant stops participating in the foraging efforts of the colony and stops communicating well with its nest-mates. Then the ant becomes hyperactive and departs from the daily rhythms of the other ants.

Most carpenter ants, for example, forage during the nighttime, but the infected ant basically becomes active all the time. That’s unusual because social insects like ants usually have something called “social immunity”, where sick members get kicked out of the group to prevent the rest from becoming infected by them. Unfortunately, some ants don’t always employ this mechanism to effectively protect themselves from Ophiocordyceps.

While the infection is 100 percent lethal, the goal of this fungus isn’t to convert all the ants into the walking dead. For ecosystems to stay balanced, these fungi tend to keep host populations in check by usually only infecting a few ants in a local colony at any given time, though they also have been known to wipe out entire colonies of ants at times.

Dead Adult Calyptrate Fly by a fungus of the Genus Ophiocordyceps
Photo from Getty Images / iStockphoto

This particular species of Zombie Ant Fungus drops its spores in the jungle on ants and takes sufficient control of them that they leave their nest and fellow ants to climb up off the jungle floor to a height of exactly 10 inches (25 cm) where the conditions are just right for the fungus to thrive and propagate.

The designated victim then attaches to the underside of a leaf with its mandibles while the fungus grows inside its host and sprouts a tiny mushroom-like growth. This fruiting body of fungus eventually distributes its spores to continue this cycle of propagation, infecting more ants in turn in a manner that is capable of infecting entire ant colonies.

Spread through Time and Space

This species shows some morphological variations due to its wide geographic range from Japan to the Americas. This may result from host-specific commitments to diverse species of ants in different areas, and helps avoid subspecies competition by occupying distinct ecological niches.

Ophiocordyceps also appears to be an ancient creature. In 2010, scientists identified a 48-million-year-old fossil of a Zombie Ant with a death grip on a leaf, verifying that zombifying fungi have been around for a while. But this fossil didn’t offer hints on how the fungus evolved.

Further work concluded that all Ophiocordyceps species descended from a common ancestor which started out by infecting the larvae of beetles that lived in rotting logs. When the beetle eggs hatched, the larvae crawled around alone inside the log, chewing on wood. When beetle larvae came into contact with a spore, the fungus would then invade the insect’s body to feed on its muscle, killing the beetle without any zombie drama. After that, the fungus would grow its stalk and spread spores around the dead body. Other larvae crawling inside the log were thus infected, prolonging this cycle of life and death.

Schematic representation of the ant behavioral manipulation caused by natural products secreted by *Ophiocordyceps unilateralis* from Wikipedia

The theory is that millions of years ago, the fungi got picked up by ants that also lived in logs. In their new ant hosts, the fungus had already acquired an ability to feed on muscles, grow stalks and spread.

But these ants brought a new challenge, because, unlike solitary beetles, ants live in crowded nests. Diseases can wipe out an entire colony, so the ants ruthlessly attack any individuals that show signs of sickness. This meant that Ophiocordyceps could not spread the way it had in beetles, just by killing its host and sending out spores. However, by keeping ant hosts healthy enough as they were being parasitized, the invasive fungus could zombify the ant host to move it out of the main nest of ants and climb up a nearby plant, from which it could spread its spores to other potential hosts.

This is how the fungi’s transition to ants set off an evolutionary explosion. Once Ophiocordyceps had evolved to live in one species of ant, it began hopping to other new species. It is also suspected that there are hundreds of other species of Ophiocordyceps still to be discovered, perhaps with a wider range of potentially infectious impact…

Growth by Infection

When the fungus infects a carpenter ant, it grows through the insect’s body, draining it of nutrients and hijacking its mind and behavior. Over the course of a week, it compels the ant to leave the safety of its nest and ascend a nearby plant stem. When this fungus invades the ant, taking over its muscles and mandibles, there is apparently no intervention into the ant’s brain itself.

The invasive fungus forces the ant to permanently lock its mandibles around a major vein on the underside of a leaf to attach itself. The ant then loses control of its mandible and remains fixed in place, hanging upside-down on the leaf. This lockjaw trait is popularly known as the “death grip” and is essential in the fungus’s lifecycle. This “death grip” prevents the ant from falling as it dies hanging upside down, thus enabling the proper growth of the fungus’ fruiting body. The “death grip” is thought to be caused by a secretion of fungal compounds that atrophies the ant’s mandibular muscles, making it impossible for the ant to unclench.

Mandibular “Death Grip” (Photo by Katja Schultz from Flickr)

Once the ant is in place on the leaf’s underside, more fungal mycelia sprout, securely anchoring it to the plant substrate while secreting antimicrobials to ward off any other competitive fungi. Next, the fungus sends a lengthy growth through the ant’s head, growing into a bulbous capsule full of spores on a single, wiry yet pliant, darkly pigmented stalk rising through the back of the ant once it is dead.

This spore-bearing sexual structure appears as a bulge on the stalk, below its tip, which forms the fungus’ fruiting body. As the ant typically climbs onto a leaf that overhangs its colony’s foraging trails, its fungal spores will then rain down upon fellow ants below, ensuring that the cycle continues.

How to Create a Zombie: The View from the Inside

How this fungus takes over its host has been carefully analyzed. Once spores drop onto an ant, they attach to the ant’s exoskeleton and eventually break through it with mechanical pressure and the help of enzymes. Yeast stages of the fungus spread throughout the ant’s body and apparently produce compounds that affect the ant’s behavior such that it exhibits irregularly timed full-body convulsions that dislodge it from its canopy nest, dropping it to the forest floor. These infected behaviors work for the benefit of the fungus in terms of its own growth and transmission, increasing its fitness and survivability.

When the fungus first enters its host, it floats around the ant’s bloodstream as single cells, replicating copies of itself. Then, at some point, these single cells join together by building short tubes, which are only seen in fungi that infect plants. Hooked up together in this way, these cells in tubes successfully communicate and exchange nutrients with each other.

The next step is to invade the ant’s muscles, either by penetrating muscle cells or growing into interstitial spaces between these cells. The result is a muscle fiber encircled and drained by a network of interconnected fungal cells in a manner unique to this species, as shown in this brief simulation that represents the process quite clearly.

Zombies that don’t eat brains?

The Zombie Ant Fungus is often described as a single entity, which corrupts and subverts a host. But this fungus can also be seen as a colony, much like the ants it targets. Individual microscopic cells begin life alone but eventually come to cooperate, fusing into a superorganism.

Together, these brainless cells can take control of a much larger creature and manipulate its behavior. But perhaps surprisingly, they do that without ever physically entering or touching the brain itself, while infiltrating the ant’s body and muscles, including its head. Thus, this fungus can manipulate its host through a very precise sort of chemically-guided muscular control that does not affect the ant’s brain. This makes the intricacy of the fungal invasion even more compelling and disturbing, depending on how aware the ant is of this intrusive occupation.

Maintaining the Life Cycle

It is worth noting that throughout its lifecycle, the fungus must meet unique challenges in its metabolic activities. First, the fungal pathogen must attach securely to the arthropod exoskeleton and penetrate it – while avoiding or suppressing its host’s defenses – and then control its host’s behavior before killing it. Finally, it must protect the ant’s carcass from microbial and scavenger attack so that it can reproduce successfully.

This invasion process, leading up to the host ant’s mortality, takes 4–10 days, and includes a reproductive stage where fruiting fungal bodies emanate from the ant’s head, eventually rupturing to release fungal spores. However, the short viability of the fungal spores presents a challenge. The fungus uses its host’s vitality to sustain the growth of the fungus’s fruiting body and enable successful reproduction. To do so, this fungus fortifies the ant cadaver to prevent its decay, which consequently ensures the prolonged growth of the fruiting body.

But this composite creature of zombie-ant fungus is, in turn and ironically, susceptible to fungal infection itself. This can limit its impact on ant populations, when it might otherwise devastate entire ant colonies. Ophiocordyceps unilateralis suffers from an unidentified fungal hyperparasite, reported in the press as the “antizombie-fungus fungus,” that results in only 6–7% of the primary parasite’s spores being viable, limiting the damage this fungus can inflict on ant colonies. This hyperparasite attacks Zombie Ant Fungus just as the fungal stalk emerges from the ant’s body, thus stopping the stalk from generating and releasing its spores.

This suppressive effect is caused by the weakening of the fungus by the hyperparasite, which may limit the viability of its infectious spores. There are additional species of fungi that can grant beneficial and protective assistance to the ant colony, as well. A complicated picture indeed!

Dr. João Araújo of the New York Botanical Garden and his team discovered two new genera of fungus. (Photos by João Araújo)

For example, two novel lineages of fungi, each belonging to its own genus, were recently discovered infecting a species of Zombie Ant Fungus in Florida. One puts a fuzzy white coating on the Zombie Ant Fungus, while the other is harder to spot, with little black blobs that look like fleas. The fungi attacking the Zombie Ant Fungus don’t zombify their host, but they do feed on its tissues and appear to cause it harm by castrating the fungus so it cannot shoot its spores any longer. Then the attacker proceeds to grow and consume the entire fungus.

Though these new parasites are the first to be seen to infect the Zombie Ant Fungus, there could be others out there. Parasitism is a lucrative form of lifestyle, experts say; it might even be the most dominant one on the planet! (Maybe our politics illustrate that…)

Ants also can protect themselves by grooming each other to remove microscopic organisms that could potentially harm the colony. Consequently, in host–parasite dynamics, both the host and the parasite are under selective pressure: the fungal parasite evolves to increase its successful transmission for reproduction, while the ant host evolves to avoid or resist the infection by the parasite, in this case the Zombie Ant Fungus. And so an evolutionary battle continues…

A fuzzy white fungus grows on top of the parasitic Zombie Ant Fungus
(Photo by João Araújo)

The principal carpenter ant hosts of Ophiocordyceps unilateralis have also evolved adaptive behaviors to limit the contact rate between uninfected and thus susceptible hosts and already infected hosts, thereby reducing the risk of transmission to their healthy fellow ants by evolving efficient behavioral forms of social immunity. As mentioned, the ants clean the exoskeletons of one another to decrease the presence of spores which are attached to their cuticles.

These ants also notice the abnormal behavior that indicates when a member of the colony is infected, resulting in healthy ants carrying infected individuals far away from the colony to avoid fungal spore exposure. Furthermore, since most worker ants remain inside the nest boundaries, only foragers who venture outside are at any significant risk of infection.

In addition, the fungus’s principal host species, the carpenter ant (or Camponotus Leonardi) tries to avoid the forest floor as a defense method by building its nests high in the canopy, with a broad network of aerial trails. These trails occasionally must move down to the ground level, where infection and graveyards occur, due to wide canopy gaps difficult for the ants to cross while staying safely high in the forest canopy. When these trails do by necessity descend to the forest floor, their length on the ground is as short as possible, only 10-18 feet (3-5 m) or so before climbing back up into the canopy. This shows that these ants avoid zones of infection wherever they can. This method of defense appears to be adaptive to this specific threat, as it is not observed in undisturbed forests where the Zombie Ant Fungus is absent.

When Ophiocordyceps unilateralis-infected ants die, they are generally found in regions containing a high density of ants which were previously manipulated and killed, which are termed “graveyards” of 70-100 feet (20-30 m.) in range. The density of dead ants within these graveyards can vary with climatic conditions, where humidity and temperature influence this fungus’s effects on the host population. It seems that large precipitation events at the beginning and end of the rainy season stimulate fungal development, which leads to more spores being released and ultimately to more individual ant hosts being infected and killed.

The Wide World of Insect Parasites

What we have here is a hostile takeover of a uniquely malevolent kind. Enemy forces invade a host’s body and use that body like a walkie-talkie to communicate with its fellows to influence the brain from afar, while exercising a more direct control over the ant’s muscles like a puppeteer. Once an infection is underway, the neurons in the ant’s body that give it control of its muscles start to die, as this fungus slowly takes over, effectively cutting the host ant’s limbs off from its brain, as it inserts itself in that place, releasing chemicals that control the ant’s muscles. After the fungus enters the ant, it propagates its invasive cells until they surround the host’s brain, at which point the fungus secretes compounds and takes over the ant’s central nervous system, enabling it to manipulate the ant to reach the forest floor and climb up the vegetation.

In this way, the ant ends its life as a prisoner in its own body, with its brain still in the driver’s seat while the fungus has seized control of the steering wheel in a cruel prolonging of the ant’s death in an agony of helpless surrender. The fungus survives and propagates successfully at the cost of these ants in this dark drama.

But not only ants can be infected with these creative parasites.

Much like the microbiome in our own guts, insects contain a whole array of fungal species, of which few have been closely studied, much less flagged for causing behavioral manipulations. Some are known, however.

One example is Entomophthora muscae, which literally means “insect destroyer of the fly” in Greek. It causes infected flies to climb a certain height, glue themselves at the mouth to a plant, and assume an abdomen-up “death pose” that’s optimal for spore dispersal. (Watch the flies turn into zombies here.)

And there’s Massospora cicadina, which pumps its cicada hosts full of hallucinogenic drugs and causes part of their abdomens to fall off. The bare-bottomed cicada then wiggles its way towards death – once again in the interest of spore dispersal.

Could this happen to us? Personally, this whole scenario gives me the willies, leaving me surprisingly sympathetic to these victimized ants and other infected insects, while also being enthralled by a sense of wonder about the endless variety of nature’s solutions to the reproductive urge of species to propagate themselves. Perhaps we humans should become more alert to all these striking opportunities for Mother Nature to assert her ultimate dominance over us. Some scientists believe that, by studying this Zombie Ant Fungus, we can learn a lot more about how the brain works – and how it might be taken over, which is surely some food for dystopian thought.

Medicinal Properties

Ophiocordyceps are known in the pharmaceutical world to be a medically important group. These Zombie Ant Fungi (Ophiocordyceps unilateralis) and related species are known to engage in an active secondary metabolism to produce antibacterial substances that protect the fungus-host ecosystem against further pathogens during fungal reproduction.

Because of this secondary metabolism, chemists who study natural products have taken an interest in this species, discovering small molecule agents of potential interest for use as human anti-infective and anticancer agents. These natural products are reportedly being investigated as potential leads in discovery efforts toward the treatment of immune diseases, cancerous tumors, diabetes and high cholesterol levels.

Another species of fungus, Ophiocordyceps sinensis, already mentioned above as a parasitic fungus-caterpillar husk combination, is prized in traditional Tibetan and Chinese medicine as an immune booster, cancer treatment, and aphrodisiac.

Moreover, red naphthoquinone pigments produced by Ophiocordyceps unilateralis are used as a dye for food, cosmetic, and pharmaceutical manufacturing processes. Curiously, naphthoquinone derivatives produced by the fungus also show a red color under acidic conditions, and a purple color under basic conditions. These pigments are stable under a wide variety of conditions as well as not being toxic, which makes them applicable both for food coloring and as a dye.

These attributes also make it a prime candidate for antituberculosis testing in TB patients, by alleviating symptoms and enhancing immunity joined with other chemotherapy drugs. So even this seemingly-nasty creature has some benefits for us humans, once we are able to look beyond its fearsome characteristics.

But this is so generally true of the wondrous variety of nature’s creatures such as featured in this series. We look at them through our human eyes, asking what they can do for us, when the whole natural world is swimming along quite well without our help or needing us for anything. The whole system should have our respect, just for including us in its amazing complexity of life forms and how it all works.

So here’s to a totally infectious and all-consuming curiosity!

Fred

Sources:
https://www.pnas.org/doi/full/10.1073/pnas.1711673114
https://hasanjasim.online/how-the-zombie-fungus-infects-ant-bodies-and-takes-control-of-their-minds/
https://en.wikipedia.org/wiki/Ophiocordyceps_unilateralis
https://www.nationalgeographic.com/animals/article/cordyceps-zombie-fungus-takes-over-ants
https://www.cnn.com/2022/11/18/world/zombie-ant-fungus-parasite-mystery-scn/index
https://www.npr.org/2023/01/30/1151868673/the-last-of-us-cordyceps-zombie-fungus-real
https://www.vox.com/culture/2023/1/21/23561106/last-of-us-fungus-cordyceps-zombie-infect-humans
https://www.nytimes.com/2019/10/24/science/ant-zombies-fungus.html
https://www.nature.com/articles/s41598-020-63400-1
https://www.nationalgeographic.com/science/article/parasitic-fungus-evolve-to-control-humans

Featured Creature: Lichen

Which creature is a combination of two other organisms, comes in bright colors, and helps us measure air quality?

Lichen!

Master of Symbiosis

Though we know lichens as creatures in and of themselves, lichens are actually a result of symbiosis, a mutually beneficial relationship between two or more species. In the lichen’s case, algae and fungi come together to form a new creature. No two lichens are alike. They vary in form, color, and which type of algae they have – either green, blue-green, or both.

The fungus gives the lichen a majority of its traits, including shape and anatomy. The algae determines the color, from orange to yellow to neon green. The fungus partners with the algae out of necessity for food. Since the algae, or cyanobacteria, can photosynthesize, they provide food for the fungus in exchange for shelter. Therefore, each party relies on the other for survival.

Abundant yet Unique

From hot deserts and windy coastlines to the arctic tundra, lichen are found around the world. In North America alone, there are thought to be 3600 different species! They grow on trees, rocks, and soil. They can even grow on things made out of one of the above, such as a house made out of wood. If a sand dune remains stable for long enough, soil crusts will form and lichens will begin to appear along the crusts. Essentially, all lichens need is something solid to hang onto.

Lichens require a stable habitat because they take a long time to grow. Every year, they only grow 1-2 mm. To promote their growth cycle, lichens will often partner with moss, adding yet another organism to the party. Mosses are simple plants (meaning they lack roots, stems, and leaves) that retain water, and since lichens have two creatures to sustain (the algae and fungi), this water source is a welcomed one. This partnership is so common that if you look up ‘lichen’ on the internet, a majority of pictures will contain both lichen and moss. They are truly geniuses of cooperation!

The lichen *Letharia vulpina* at Mt. Gleason, CA (Photo by Jason Hollinger from Wikipedia, CC BY-SA 3.0)

Welcomed by All

At first glance, it may look like lichens harm trees. (After all, if you or I had something bright green or orange growing on our limbs, we should call the doctor). But fear not – lichens don’t harm any plants they attach themselves to. On the contrary, they benefit many other species, such as birds that use lichen as nesting material. Numerous invertebrates see lichen as a source for food and shelter and, as a result, the more lichen in a forest, the more organisms the ecosystem can sustain.

Humans have reaped the benefits of lichen, too. We have used them for clothing, decorations, and food. They are also highly valued for their antibiotic properties. Today, we use them in toothpastes, salves, deodorants, and other products. So you can thank lichens for helping us stay clean and healthy!

Cup Lichen (Image by Jürgen from Pixabay)

A Climate Helper

Since the algae in lichen photosynthesize, lichens contribute to the important function of converting carbon dioxide in the atmosphere to oxygen. The fungus in lichen contribute to this function, too, by allowing algae to live in places they wouldn’t be able to on their own. By providing a form of shelter, the fungus gives an opportunity for more algae to exist and thrive, and that means we have more creatures sequestering carbon and stabilizing the climate.

Lichens also play a vital role in soil formation and development by helping to break down solid minerals like rock. This process creates pockets in the soil – perfect for larger organisms to thrive in. It also creates pathways for nutrients to sink deep into the Earth, where they will later benefit plants and other creatures. As we like to say at Bio4Climate, healthy soil makes for a healthy planet.

Last but not least, lichens give us an insight on the amount of pollution in their respective area. Lichens absorb everything around them – including air, nutrients, water, and pollutants. Scientists study lichens in order to understand the type of toxins present in the environment and their levels. This information gives us insights on the root causes of disease and environmental degradation. With that knowledge, we can address issues affecting human and wildlife communities – creating a cleaner environment for us all.

That’s all for now, but I hope you’re lichen this series!
Tania

Tania graduated from Tufts University with a Master of Science in Animals and Public Policy. Her academic research projects focused on wildlife conservation efforts, and the impacts that human activities have on wild habitats. As a writer and activist, Tania emphasizes the connections between planet, human, and animal health. She is a co-founder of the podcast Closing the Gap, and works on outreach and communications for Sustainable Harvest International. She loves hiking, snorkeling, and advocating for social justice.

Sources:
https://www.deschuteslandtrust.org/news/blog/2016-blog-posts/five-fun-facts-about-lichen
https://www.fs.fed.us/wildflowers/beauty/lichens/about.shtml
https://www.woodlandtrust.org.uk/blog/2019/04/what-is-lichen-seven-types-of-lichen-found-on-trees/
https://digitalcommons.humboldt.edu/cgi/viewcontent.cgi?article=1078&context=ideafest

Featured Creature: Poison Dart Frog

pixabay.com

What creature the size of a paperclip is lethal enough to kill ten grown men?

The poison dart frog!

What makes the poison dart frog so powerful?

Poison dart frogs – so named because the Indigenous Emberá people of Colombia traditionally used the venom in blow darts – are some of the most toxic creatures on Earth. Some carry enough poison to kill ten grown men or to poison 20,000 mice.

This potent toxicity originally comes from plant poisons that were ingested by the frogs’ insect prey. The effects of this diet, whose repercussions pass from plant to insect to frog to human hunters, shows just how interconnected these ecosystems are. Though it’s not established how the plant poison is processed into venom, when poison dart frogs are bred in captivity and fed a different diet, they do not develop the venom.

Why are poison dart frogs so colorful?

The poison dart frog uses bright colors and patterns as a warning to predators – do not attack if you wish to live! Various species come in bright yellow, turquoise and black, or strawberry red, and these eye-catching visuals broadcast to predators that they’re venomous and dangerous.

They use poison in self-defense, not in hunting, excreting venom into their skin when they’re threatened, so that a single touch would be enough to stop a human heart. This is such an effective tool that many species have evolved to mimic the bright colors and patterns of poison dart frogs in order to get some of that protection from predators by association.

What are other characteristics of poison dart frogs?

They’re tiny! Grown adult frogs typically measure one to two inches, and can be held on a single fingertip (though you wouldn’t want to try this at home).

Like all frogs, they’re amphibious, which means they lay eggs that hatch tadpoles, and have permeable skin through which they can absorb water and oxygen.

How are human activities impacting poison dart frogs?

Deforestation is one of the biggest threats to the poison dart frog. Poison dart frogs are spread across the rainforests of Central and South America. There are over one hundred species of them, and new ones continue to be found! However, habitat loss across these areas, especially in the Amazon, put them at risk of extinction.

Check out this brief look at the life of one golden dart frog:

These bright creatures may be dangerous, but they are just as dazzling. They show that brilliant things can come in small packages.

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The Fruit – Sweet & Versatile

A Tale of Two Ecosystems

Innovative Uses: From Energy to Eco-Friendly Materials

Sources and Further Reading

Sloths, Moths, and Little Green Friends

A Slow but Important Presence in the Rainforest

More than meets the eye

How does it spread?

Impact

Foraging Japanese knotweed

Managing knotweed

Showstoppers: Stunning Species from Around the World

Cicadas vs. Locusts: Clearing Up the Confusion

Cicadas’ Impact: How They Shape the Ecosystem

Cicadas as Ecological Signals: What They Tell Us About Nature

Challenges Facing Cicadas: The Threats to Their Survival

A Month of Delight

Birds of a Feather

So, are they as colorful as everyone says?

Are kingfishers Really Kings of Fishing?

Can the blue-but-not-really-blue kingfisher get any more interesting?

Learning from kingfishers

Kingfishers: A Little More Like You Than You Think

Lovebirds!

Both Beauty and Brains

Lifestyle and relationships

Communication and Complexity

Birds of a Feather Flock Together

Master of Symbiosis

Abundant yet Unique

Welcomed by All

A Climate Helper

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