Creature: Burrowing Animals

Featured Creature: Leafcutter Bee

What creature carves out little pieces of tree leaves to build its nest inside hollow stems?

The Leafcutter Bee!

Bernhard Plank – SiLencer (CC BY-SA 3.0 via Wikimedia Commons)

Known scientifically as Megachile (genus), leafcutter bees account for 1,500 of the world’s 20,000 bee species. I first noticed the work of leafcutter bees in my own backyard two years ago. First, you notice the “leaf damage” of the leafcutter bee. 

Here is the “leaf damage” on a pin oak seedling. 

The leaf damage takes the form of neat little curves. I recognized these neat little curves from having perused Bees: An Identification and Native Plant Foraging Guide, by Heather Holm, an author whose work I highly recommend. 

In June of this year, I was fortunate enough to capture a leafcutter bee on video doing her work. I’ll show you the video below, but first … 

How can we coexist with critters who are “harming” our plants?

It is said, “If nothing is eating your garden, then your garden is not part of the ecosystem.” If you want your garden to be part of the ecosystem, then some of it will become food for other critters. Some of my leaves will become food for leafcutter bees. But then the leafcutter bees will pollinate my wildflowers and my vegetables, making it possible for them to bear seed and fruit. I am happy to make this trade-off, plus I want my garden to feed all of the living species, not just us humans.

How do leafcutter bees differ from honeybees?

Honeybees are the most famous bees. And who doesn’t like honey? But honeybees are only one species out of 20,000 worldwide.  

Honeybees are social. So they live cooperatively in hives. But most bees are solitary, including leafcutter bees. They interact only in mating. And then they make their nests and lay their eggs in a nest that could be in the ground, or in a rotting tree or in the hollow stem of a dead wildflower.

The North American continent is home to 150 of the world’s 1,500 species of leafcutter bees. Honeybees originate from Europe; they are not native to North America. 

An “unarmed leafcutting bee” from my backyard

Here is a video of an “unarmed leafcutter bee” in my backyard, cutting the leaf off a pin oak seedling. This female uses her strong mandibles (jaws) to carve out a piece of a pin oak leaf to build her nest. Notice how quickly and efficiently she does this work.

How do I know this is a female? Because only the females build nests. The males die shortly after mating. 

As soon as she is done cutting off the piece of leaf, she carries it back to the nest. The female nibbles the edges of the leaves so they’ll be pulpy and stick together to provide the structure for the nest.

Where is she building a nest? 

She may build her nest in the hollow stem of a dead wildflower stalk, such as ironweed or goldenrod. She may build her nest in a dead tree. (Forest ecologists say that a dead tree is at least as valuable as a live tree, because so many critters make their nests in them.) Or she may build it in the ground. Nests also include cavities in rocks and abandoned mud dauber nests (Holm, 2017).

Here is the nest of a ground-nesting bee. In this case, it may or may not be a leafcutter bee.

If we leave bare spots on the ground, then this becomes a potential nesting site for ground nesting bees, including some leafcutter bees.

What purposes do the leaves serve?

Leaves prevent desiccation (drying out) of the food supply. The leaves typically include antimicrobial properties, preventing the nest from being infected.

Inside a nest, cells are arranged in a single long column. The female constructs each cell with leaf pieces, placing an egg along with pollen mixed with nectar, enough food for the bee to grow to adulthood, before leaving the nest.

In the fall, the larvae hatches from the egg, eats the nectar and pollen, and gains enough energy to grow through several stages, called instars. But it does not yet leave the nest. In the spring, the larvae pupates and becomes an adult, finally crawling out of the nest.

In the eastern U.S., common nesting materials include rose, ash, redbud and St. John’s wort. See below for photos from my home landscape showing the work of leafcutter bees on my pin oak, silver maple and jewelweed.

Where do leafcutter bees gather pollen and nectar?

Heather Holm, author of Bees: An Identification and Native Plant Foraging Guide, lists the following forage plants where leafcutter bees gather nectar and pollen:

Spring Forage Plants: 

  • Golden Alexander (Zizia aurea)
  • Purple coneflower (Echinacea purpurea)
  • Foxglove beardtongue (Penstemon digitalis)

Summer Forage Plants: 

  • Black-eyed Susan (Rudbeckia hirta)
  • Common milkweed (Asclepias syriaca)
  • Butterfly weed (Asclepias tuberosa)
  • Joe Pye weed (Eutrochium purpureum)
  • Anise hyssop (Agastache foeniculum)
  • Blazingstar (Liatris pycnostachya)
  • Blue vervain (Verbena hastata)

Autumn Forage Plants: 

  • Goldenrod, species of Solidago, including showy goldenrod (Solidago speciosa)
  • Asters, i.e., species of Symphyotricum, including New England aster, (Symphyotricum novae-angliae)
Here is a picture of Megachile fidelis, the faithful leafcutting bee, gathering nectar and pollen from a New England aster.
Joseph Rojas – iNaturalist (CC BY 4.0 via Wikimedia Commons)

Specialist Leafcutter Bees

Some leafcutter bees specialize on the aster family of plants, known as Asteraceae. So we can support these bees around our home landscape by cultivating any representatives of the Asteraceae family, including goldenrod, sunflowers, ironweed and wingstem.

Check out this video of a female leafcutter bee carving out a leaf piece from a China Rose.

More leafcutting from leafcutter bees in my backyard

Here is evidence that a leafcutter bee was carving off pieces of a silver maple leaf (left). Here, leafcutter bees have been working on a jewelweed plant (right).

The following are photos of flowers from my home landscape, all of which make excellent forage for pollinators, including leafcutter bees.

Purple coneflower
(Echinacea purpurea)
Cutleaf coneflower
(Rudbeckia laciniata)
Blunt Mountain Mint (Pycnanthemum muticum)
False Sunflower
(Heliopsis Helianthoides)
Cup plant
(Silphium perfoliatum)
Butterfly weed
(Asclepias tuberosa)
Brown-Eyed Susan
(Rudbeckia hirta)

This is my front yard garden from 2022. 

Included here are four great forage plants: Maximilian sunflower (Helianthus maximiliani), white crownbeard (Verbesina virginica), frost aster (Symphyiotricum pilosum) and New England aster (Symphiotricum novae-angliae)

Grow your garden and grow an ecosystem. Cultivate a diversity of native plants and avoid pesticides.

—Hart

Hart Hagan is a Climate Reporter based in Louisville, KY. He reports on his YouTube channel and Substack column. He teaches a course for Biodiversity for a Livable Climate called Healing Our Land & Our Climate. You can check it out and sign up for a class here.

Photos by Hart Hagan, except where noted.

Sources and Further Reading:

Featured Creature: Aardvark

What unique animal could be a cross between a rabbit, a pig, an opossum, and an anteater?

The aardvark!

Photo by Kelly Abram from iNaturalist

Meet the aardvark – a one-of-a-kind mammal native only to sub-Saharan Africa.

The aardvark has an unusual hodge-podge mix of features including rabbit-like ears, a pig-like snout, an opossum-like tail, and a long, sticky anteater-like tongue. This creature has large and formidable claws used for digging and defense. Weighing in at 115 – 180 pounds, the aardvark is much heftier than it looks. 

Aardvarks inhabit the savannas, arid grasslands, and bushlands of sub-Saharan Africa where there is plenty of their favorite prey, ants and termites. They are solitary and do not socialize with others unless for mating or raising young. They live for about 18 years in the wild and approximately 25 years in captivity.

The aardvark is famous for being the first noun in the English dictionary. The animal goes by many names including Cape anteater and ant bear, but its colloquial moniker, aardvark, is Afrikaans for “earth pig”.

Photo by Louise Joubert from Wikimedia Commons

Odd Relatives

Although the aardvark is an eater of ants, it is not an anteater. Understandably, the comparison comes from its similar appearance and nearly identical diet to the anteater, which leads people to assume they are the same animal. However, the aardvark is its own species entirely, and in fact, it is more closely related to elephants than to anteaters. 

Unique Diet

Aardvarks are insectivores that eat ants and termites. They use their keen sense of smell to locate ant nests and termite mounds over great distances. Aardvarks have the highest number of olfactory turbinate bones of any mammal on the planet. An aardvark has about 9 -11 of these specialized bones which help support the olfactory bulb in the brain, where smells are processed. This larger-than-average olfactory system allows the aardvark to track such tiny creatures like ants and termites from far away. They have been observed swinging their heads back and forth close to the ground, much like a metal detector, to pick up a scent. 

Once an aardvark locates a termite mound, it uses its claws to break open the cement-hard structure. Its tongue, coated in sticky saliva, slurps up the exposed insects in seconds. The highly adapted tongue of an aardvark can be up to 1 foot long. Over the course of a night, a single aardvark eats over 45,000 termites. Amazingly, all of this is done without chewing. 

While aardvarks are classified as insectivores, they make one exception in their diet for a very unique fruit, the aardvark cucumber. This African melon looks similar to a cantaloupe but is grown completely underground. Aardvarks easily dig up the fruit and eat its watery, seed-filled interior. Once the fruit is digested, the seeds are dispersed by the aardvarks that cover their dung in dirt, effectively planting these seeds in the soil with a natural fertilizer. This symbiotic relationship helps propagate the aardvark cucumber, whose existence is entirely dependent upon the aardvark.

Photo by Nick Helme from Wikimedia Commons

Cultural Significance

The aardvark is regarded as a symbol of resilience in some African cultures due to its unrelenting bravery in tearing down termite mounds. The aardvark has very thick skin which helps avoid injury from hundreds of termite and ant bites. Because of their nocturnal habits and solitary nature, aardvarks are not a common sight during the day. It is said that anyone who is lucky enough to see one is blessed. 

Earth Engineer

Aardvarks are adept earth-movers known to create specialized burrows to live in. These burrows provide shelter away from the sun and from predators. Its powerful claws are specially adapted to move massive amounts of dirt in minutes, which helps the aardvark excavate multiple chambers within the den.  

Some burrows can be up to 10 feet deep and over 20 feet long. There are multiple entrances to the same burrow so the aardvark has a chance to escape if a predator poses a threat. Aardvarks have been observed to be very cautious creatures and practice an unusual ritual before exiting their abode. The aardvark stands at the edge of its burrow and uses its excellent sense of smell to detect any nearby predators. It listens for danger and emerges slowly. The aardvark then jumps a few times, pauses, and heads out for the night. Because aardvarks are primarily nocturnal, they don’t have much need for vivid sight and are colorblind. Their long ears and nose do the seeing for them. 

The physiology of these soil architects may strike some as strange, but it serves a purpose. The odd, arched silhouette of the aardvark is caused by its hind legs being longer than its front, which gives them a stronger stance when digging. This adaptation, combined with their formidable claws and muscular forelimbs, allows the aardvark to dig a hole 2-feet deep in just 30 seconds – much faster than a human with a shovel.

Photo by Louise Jobert from Wikimedia Commons

Ecological Importance

When aardvarks have depleted most of their territory’s termite mounds or ant nests, they must move on to new hunting grounds. Their abandoned burrows don’t stay empty for long and are occupied by a variety of species. Hyenas, wilddogs, warthogs, civets, and porcupines make their homes in aardvark burrows. The aardvark has an incredible impact on its environment by sculpting the very landscape itself and providing shelter for other creatures.

If you want to learn more about how aardvark burrows support other animals, check out this article documenting the one of the first observations of predators and prey cohabitating in the same burrow.

Burrowing away now,
Joely

Joely Hart is a wildlife enthusiast writing to inspire curiosity about Earth’s creatures. She holds a Bachelor’s degree in creative writing from the University of Central Florida and has a special interest in obscure, lesser-known species.

Sources and Further Reading:
https://www.miamiherald.com/news/nation-world/world/article274890346.html
https://www.thoughtco.com/10-facts-about-aardvarks-4129429
https://a-z-animals.com/animals/aardvark/
https://animalia.bio/aardvark#facts
https://www.britannica.com/animal/aardvark
https://carnegiemnh.org/a-is-for-aardvark/
https://nationalmuseumpublications.co.za/aardvarks-orycteropus-afer-and-their-symbolism-in-african-culture/

Featured Creature: Groundhog

What cute creature is an underground architect and an amateur meteorologist?  

The Groundhog!

Image by Harkiran Kaur from Pixabay

Groundhogs are famous rodents who enjoy the spotlight in early February, when people in the US and Canada celebrate Groundhog Day. These critters also go by woodchuck, whistle-pig, wood-shock, whistler, marmot, thickwood badger, red monk, land beaver, weenusk, monax, and groundpig.

Beyond their supposed (and generally debunked) prowess at predicting seasonal changes, these cuddly creatures exhibit a fascinating blend of behaviors and ecological significance. Groundhogs belong to the squirrel family as one of the 14 species of marmots, which are also aptly known as ground squirrels. Indeed, groundhogs’ fifteen minutes of fame, and their lives outside of it, are shaped by their burrowing talent and how that ties into their seasonal habits.

Image by Stefaan Van der Biest from Pixabay 

Life Underground

A defining characteristic of groundhogs is their habit of hibernating through the winter months. They spend the warmer seasons gorging themselves on vegetation, accumulating ample fat reserves to sustain them through the winter slumber. During hibernation, their heart rate drops and their body temperature lowers, enabling them to conserve energy in their underground burrows.

Burrowing is a hallmark behavior of groundhogs, with complex, multi-chambered burrows extending up to a total of 65 feet in length. These subterranean dwellings serve as multi-functional spaces where groundhogs sleep, raise their offspring, and even excrete waste in specific, separate tunnels. Intriguingly, the burrows also provide refuge for other wildlife species, which helps support the overall biodiversity of their habitats. Much like the dens of the related prairie dog, these burrows can shelter other species in times of need, offering a place of refuge during fires or cold snaps, or simply a home base to hide out from the usual predators. 

Cultural and Ecological Connections

Groundhog Day, celebrated on February 2nd each year, has captured the imagination of people across the United States and Canada. According to tradition, if a groundhog emerges from its burrow and sees its shadow, there will be six more weeks of winter, and if it doesn’t see its shadow (which happened this year), spring will come early. However, a study conducted in 2021 surveying years of predictions and seasonal records revealed that groundhogs’ predictions seem to be pure chance, with accuracy rates hovering around 50 percent.

Image by Kristie from Pixabay

Despite their failed reputation as predictors of seasonal changes, groundhogs excel in other aspects of survival. They are skilled foragers, feeding on a variety of vegetation, including leaves, flowers, and field crops. Their burrowing activities also play a crucial role in mixing and aerating the soil, a process which enhances nutrient absorption essential for plant growth.

While groundhogs are classified as species of least concern on the International Union for Conservation of Nature (IUCN) Red List, they face challenges in areas where they are overly abundant. Considered pests by some due to their burrowing activities, groundhogs occasionally come into conflict with humans, particularly farmers who may experience damage to gardens and crops.

Groundhogs are integral components of their ecosystems, providing shelter for various wildlife species and contributing to soil health through their burrowing activities. While adults are known to defend themselves fiercely against predators using their powerful claws and teeth, young groundhogs are more vulnerable to predation, particularly from birds of prey like hawks and other raptors.

Check out this short and sweet video from the Missouri Department of Conservation on Groundhogs:

Let us honor Groundhog Day as a reminder to be attentive to the organisms and ecosystems around us. The more we learn from one another, the better we can participate in the complex web of life in which we all play a role. 

Burrowing away now,

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://www.nationalgeographic.com/animals/mammals/facts/groundhog?loggedin=true&rnd=1706906040576
https://carnegiemnh.org/groundhog-architecture/
https://mdc.mo.gov/discover-nature/field-guide/woodchuck-groundhog
https://www.britannica.com/animal/groundhog
https://thehill.com/changing-america/enrichment/arts-culture/3840820-the-history-of-groundhog-day-is-more-complex-than-you-may-think/

Featured Creature: Prairie Dog

Have you ever heard of a squirrel that barks?

Let me introduce you to the Prairie Dog. 

Cephas (Wikimedia Commons)

Sometimes, when walking alone in the high grasslands of the Western United States, you may feel as if you are being watched. 

My first encounter with prairie dogs in the wild occurred as I stood in an empty prairie just outside of Badlands National Park in South Dakota. As I meandered along, minding my own business, dozens of furry creatures with beady little eyes appeared, propped themselves up on their hind legs, and began to follow my every step. Prairie dogs are adorable, it is true, but when you see a dozen spread out, standing upright, watching you intently, it can be a bit disconcerting.

They were, however, no threat, and weren’t eyeballing me just to judge me. A prairie dog standing on his hind legs – “periscoping” as it is known – is simply keeping watch for predators. And their distinctive bark? It may sound like “yip,” but it is actually a sophisticated language developed over thousands of years that is still not fully understood by scientists. 

Prairie dog barks convey everything about a predator’s size, speed, and location. According to a study at the University of Northern Arizona led by Con Slobodchikoff, Ph.D (see video linked below) pitch, speed, and timbre were all altered in a consistent manner corresponding to the species of predator and the characteristics of each. Certain “yips” could even be interpreted to represent nouns (the threat is “human”), verbs (the “human” is moving toward us), and adjectives (the “human” is wearing an ugly yellow shirt). So now that I think about it, I guess they were judging me, and I am not sure how I feel about that. But still, those are some impressive squirrels.

Wait, did you say squirrels?

Yes.

Squirrels. From the Sciuridae family. Prairie dogs are marmots (or ground squirrels) that bark like a dog, prompting Lewis and Clark to label them “barking squirrels,” which may lack points for creativity but is at least more accurate than calling them “dogs.” Prairie dogs, in fact, have no connection to dogs whatsoever.

Amaury Laporte (CC BY 2.0 via Wikimedia Commons)

There are five major species of prairie dog, who all live in North America at elevations between 2,000 and 10,000 feet. The Black-Tailed prairie dog covers the largest territory, filling an extensive region from Montana to Texas. Gunnison’s prairie dogs occupy the southwest near the Four Corners region. White-Tailed prairie dogs reside in Wyoming, Utah, and Colorado. Mexican and Utah prairie dogs belong to Mexico and Utah, respectively, and both are considered endangered.

As you may have observed, prairie dogs live in areas prone to harsh extremes of weather. To protect themselves, they dig extensive burrow networks with multiple entrances, designed to create ventilation, route flood water into empty chambers deep underground, and keep watch for predators. Their burrows connect underground, organized into sections called “coteries,” each of which contains a single-family unit responsible for the maintenance and protection of their area. Multiple coteries become “towns” of startling size and complexity. According to the National Park Service, the largest prairie dog town on record covered 25,000 square miles, bigger than the state of West Virginia!

That IS an impressive squirrel.

Indeed.

Amaury Laporte (CC BY 2.0 via Wikimedia Commons)

Over the years, however, the prairie dog’s range has shrunk, scientists estimate, by as much as 99%, largely because of agriculture. Farmers and ranchers tend to regard prairie dogs as a nuisance, as they sometimes eat crops (they are mostly herbivores) and their holes create a hazard for livestock. They will bulldoze their towns or conduct contest kills to remove them, which has had devastating impacts.

Experts consider prairie dogs to be a keystone species. Their loss affects hundreds of other species who rely on them for food or use their burrows for shelter. They are instrumental in recharging groundwater, regulating soil erosion, and maintaining the soil’s level of production. Prairie dog decline, in fact, eventually leads to desertification of grassland environments.

So, an impressive AND important squirrel?

Yes, and the restoration of prairie dog habitats could be a crucial step in mitigating the effects of climate change.

If you’ve caught prairie dog fever, dive deeper into the resources below. And to learn more about Prairie Dog language, check out this fascinating video:

Hoping one day to converse with my personal prairie dog army,

Mike

Mike Conway is a part-time freelance writer who lives with his wife, kids, and dog Smudge (pictured) in Northern Virginia. 

Sources:
https://animals.net/prairie-dog/
Prairie dog – Wikipedia
https://www.humanesociety.org/resources/what-do-about-prairie-dogs
Prairie Dog Decline Reduces the Supply of Ecosystem Services and Leads to Desertification of Semiarid Grasslands | PLOS ONE
Prairie Dogs | National Geographic
Prairie Dogs: Pipsqueaks of the Prairie (U.S. National Park Service) (nps.gov)