Field Guide to February 2023

Stories in the Snow

By Kent McFarland

A snowy winter may be bad news for your commute to work, but it is great news when it comes to animal tracking. Anywhere from a light dusting to a few inches of snow on the ground can reveal the travels of squirrels, foxes, fishers, and numerous other animals through the woods and even right through your backyard! Animal trails can tell all kinds of stories, and following them in the snow can reveal interesting behaviors, raise new questions, and help you learn about how animals navigate the landscape, whether you know exactly what species’ tracks you’re looking at or not.

iNaturalist can help you narrow down the ID of those footprints in the snow with the help of advanced software and a massive network of tracking experts ready to lend a hand. Submit your observations of animal tracks and trails to the Vermont Atlas of Life on iNaturalist, and be sure to include something like a coin, ruler, or key in the photo as a size reference.

Winter Wasp Watching

By Spencer Hardy

Despite the cold and snow, January is a great time to get out and look for wasps. Well, at least the Family Cynipidae—commonly referred to as the Gall Wasps. Fifty-nine species have been documented on iNaturalist in Vermont; at least a few are most noticeable in winter. Technically it’s not the wasps you are looking for but the changes in plant growth that the wasp has induced as it develops within the plant tissue that comprises the gall. A wide range of arthropods can cause gall formation—from midges to mites to moths, though the mechanism(s) of gall formation remains poorly understood. As for gall ID, a new resource—The Field Guide to the Wasp Galls of Herbs and Brambles in North America—is freely available to help understand and identify the diversity of species that form galls within herbaceous plants. For the eager naturalist, now is a great time to search for some of these galls, especially those on brambles. And if you’re interested in taking it a step further, the field guide also includes a section on rearing wasps from galls to see the adults that made them.

If you happen across any galls on your snowy adventures, please make sure to share them with the Vermont Atlas of Life on iNaturalist.

The Howl of Winter

By Kent McFarland

Eastern Coyote breeding season peaks now—around the middle of February. The howl of coyotes can usually be heard on winter nights, especially during mating season. They typically begin breeding at two years of age and may mate for life. The gestation period is approximately nine weeks, with an average litter of six pups. The Eastern Coyote is an opportunistic omnivore. It is both a predator and a scavenger, with a widely varied diet. They’ll eat small rodents, plants, fruit, deer, Snowshoe Hares, Cottontail Rabbits, insects, birds, and even a Woodchuck.

Add your sightings to the Vermont Atlas of Life on iNaturalist, and see where others have heard or seen them too.

Coyote? Eastern Coyote? Coy-dog? Coy-wolf? What is this canine? Learn more about its name and natural history from the VPR podcast – A Brave Little State.

Sleeping: Do Not Disturb

By Kent McFarland

Black Bears aren’t true hibernators. Sure, their respiration and metabolic rate decrease during winter sleep, but their body temperature remains close to normal. A bear in a winter den can be easily aroused within moments, but an animal that is a true hibernator may take several hours to come to its senses.

Size matters. The largest mammals that are true hibernators are Marmots that tip the scales at about 11 pounds, such as Woodchucks (AKA Groundhogs) here in New England. If Grizzly Bears were to hibernate, they would require over 11 million calories to warm up and wake up! 

For animals that are true hibernators—body temperature, respiration, and metabolic rates are all considerably decreased. Take the Woodchuck as an example. Their heart rate goes from 80 beats a minute when active to just 4 or 5 beats a minute when in hibernation. Their body temperature drops from 98 degrees to a mere 38 degrees Fahrenheit. A Woodchuck’s incisors grow continuously and are kept short through their constant gnawing. But during the winter hibernation, growth stops. True hibernators do wake up every few weeks to nibble on food and, in the case of the Woodchuck, use the underground outhouse.

Food supplies are the most critical factor determining when Black Bears den each fall. When food is abundant, they’ll continue eating throughout the snows of November and into December. When autumn foods are scarce, most bears den by mid-November.

The den is commonly a brush pile. It may also be a pocket or cave in rocky ledges; a hollow in a large tree or a fallen log; a sheltered depression or cavity dug out at the base of a log, tree, or upturned root; or even a simple hole dug into a hillside. Male bears den up almost anywhere. Females, however, are more particular, selecting protected sites and lining them with stripped bark, leaves, grasses, ferns, or moss.

Remember, if you come across signs of a den, make sure to give it plenty of space! Check out this episode of Outdoor Radio to learn more about bears in winter.

The Crossbill ENIGMA

By Kent McFarland

Red Crossbills (Loxia curvirostra) remain an enigma, and birders like you can help solve some of the mysteries. Red Crossbills come in many shapes and sizes that appear to match their main food sources. There’s one called the Appalachian Red Crossbill, which has a medium-sized bill. Another, called the Newfoundland Red Crossbill, has a large beak and mostly feeds on Black Spruce. The Cassia Crossbill (Loxia sinesciurus) was just another one of these red crossbill populations, found only in the South Hills of Idaho, until just this year when there was enough evidence to elevate it as its own species. Many scientists now recognize many ‘types’ of Red Crossbills. Understanding how these different types wander about the continent, or not, is a puzzle that will require an army of observers – birders like you – armed with recording devices and eBird.

Ornithologists have discovered that each Red Crossbill population gives a distinct flight call. The flight calls are the sound typically described as jip-jip-jip and usually heard when the birds are flying overhead, but sometimes even when they are perched. As many as 10 ‘call types’ of Red Crossbill can be found across North America. These call types have been found to correspond to slight differences in size, genetics, and core habitats.

Identifying a call type by ear is a challenge, but with experience, some differences can be learned. But to be sure of the identity of the call type, ornithologists use audiospectrographic analysis. Raven Lite software can be used to do this analysis. The software produces an image of the flight call. Since each type of flight call has a specific shape and frequency, scientists can match them for an identity or type. In addition to flight calls, Red Crossbills also give other calls and various songs. Excitement calls, known as “toop” calls, can aid in identification to call type too. Songs aren’t much help for typing, at least not yet.

Anyone with a recording device – from a smartphone to professional-grade equipment – can capture recordings and add them to eBird so they can be identified to the call type. Learn more about this on the VCE Blog.