While crayfish are the most common crustacean in the United States, we don’t commonly see them on on the farm. This one was found by my son in the barely seeping fall headwaters of Carroll Creek. There is one fact that everyone should know about crayfish; they eat almost everything. Omnivores in the extreme, there’s nothing a crayfish won’t try: insects, tadpoles, algae, plants, dead animals, etc. They’ll feast on almost anything. In fact, one source states that 40% of their brain is devoted to their sense of smell – your brain only uses 1% – in order to help them find food.
Eastern tent caterpillars are generally not well liked. They can quickly defoliate small trees and gather in repulsive, squirming colonies. As if that weren’t bad enough, pregnant mares who accidently eat tent caterpillars are known to abort their fetuses. These facts make it even more surprising that these creatures are in fact one of the most fascinating caterpillars found on the farm. Not only are the amazingly sociable larvae capable of building the biggest nest of any tent caterpillar, they also vomit deadly cyanide when threatened.
Their nests are engineering marvels that are carefully constructed to keep the caterpillars warm. This is important because they can’t digest their food if they get too cold. Nests are typically started where two branches divide and expanded daily with new layers of silk. The widest side of a nest often faces the morning sun to capture as much warmth as possible. After several weeks, the nests develop into a multi-chambered, greenhouse-like structures that allow the caterpillars to control their body temperature. Their habit of gathering together in a large mass is also believed to have evolved in an effort to keep warm.
Their ability to produce cyanide is partially a result of their prefered diet of cherry tree leaves. Cherry leaves – especially those from the black cherry tree – are cyanogenic and provide the caterpillar with the raw materials necessary to make the poison. As a result, tent caterpillars are threatened by few predators other than the parasitic wasps and flies who lay their eggs on unsuspecting larvae.
While undeniably destructive, the damage done by these caterpillars often does not have a significant economic impact. Infested trees are typically ornamental and quickly sprout new leaves once the larvae leave to start the next phase of their life cycle.
The Variegated Fritillary is one of the many butterflies that enliven the farm’s fields and roadsides from late spring through fall. While it thrives from Argentina up through North America’s East Coast, its amazingly wide range also includes much of the United States and even extends into Canada. The Fritillary’s caterpillar hosts on leafy plants and vines including mayapple, moonseed, violets, and pansies. Adults typically feed on nectar from butterfly weed, milkweed, red clover, and, as seen in the photo, tickseed sunflower (Bidens aristosa).
A grove of ancient pecan trees draws a large number of gray squirrels to the farm. These industrious mammals are scatter hoarders. They can hide thousands of caches every year and feed on the stored nuts and seeds during times of scarcity. Primarily nesting either in collections of sticks and leaves called dreys or hollow tree trunks, female gray squirrels can give birth twice a year. They also do not hibernate. Instead they often share their nests on cold winter nights. Crepuscular by nature, gray squirrels are most active in the early morning and evenings.
A member of the Robber Fly (Asilidea) family, these flying terrors are also known as Assassin flies. Similar to dragonflies, Cannibal flies are voracious hunters who in ambush their prey in mid-air. After capturing the bees, ants, grasshoppers, dragonflies, and other insects they feed on, Cannibal flies inject neurotoxins and proteolytic enzymes using their proboscis. The fly will then find a quiet spot to rest as it sucks out the liquified internal organs of it victim. Ferocious and amazing.
Largest of the native skinks in Virginia, broadhead skinks are virtually indistinguishable from five-lined skinks when young. With the blue tails and five lighter lines, only a slight variation in their scales distinguish them from their cousins. Adult females – which can grow up to 13″ long – are typically larger than adult males and retain their lines. As seen in the photo, adult males have a more uniform body color offset by an ostentatious red-orange head and neck during the spring mating season.
Spending time on the ground as well as in trees, these non-poisonous insectivores reproduce by laying eggs. Common throughout the Southeastern United States they typically are seen around our house and in the adjoining planting beds. As a child I remember skinks being fairly rare, but their numbers have increased over the past 10 years to a point where they are now a common site during the warmer months.
This is an easy one to start with. The second most abundant bird in North American, robins are endemic on the farm and are the first migratory birds to arrive in late winter and possibly winter over. Easily identifiable by their reddish-orange breast, they are often seen in large flocks on the farm in the early spring but become more solitary in the summer. They are profuse breeders. According to wikipedia, produce two to three broods a year hatched from their distinctive blue eggs. This fecundity appears to be much needed as only 25% of young robins survive their first year and the average lifespan is a short two years.
The robin pictured below was photographed on an August morning atop a willow oak. With a mouth full of invertebrates, this master hunter was no doubt rushing home to feed its last hatchlings of year.