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Sunset on the Green Mountains in February. K.P. McFarland

Field Guide to February 2022

This month, wildlife and the rest of us here in New England will cross a threshold that's arbitrary yet not insignificant: 10 hours of daylight. There's no doubt that we’ve got a lot more winter ahead, but change is coming. So here are a few February natural history tidbits to help get your hopes up, no matter what that groundhog predicted.

By Vermont Center for Ecostudies February 3, 2022

This month, wildlife and the rest of us here in New England will cross a threshold that’s arbitrary yet not insignificant: 10 hours of daylight. You can sense it when you head out in the morning—Black-capped Chickadees and Northern Cardinals are among the birds breaking into song, and Downy and Hairy woodpeckers are starting to drum. There’s no doubt that we’ve got a lot more winter ahead, but change is coming. So here are a few February natural history tidbits to help get your hopes up, no matter what that groundhog predicted.

Eastern Screech-Owl © Kyle Tansley
Eastern Screech-Owl © Kyle Tansley

A Hoot of a Valentine

By: Julia Pupko

We humans are not the only ones sending valentines this month. February marks the beginning of Eastern Screech-Owl courtship, which proceeds their breeding season in mid-March through mid-May. These small owls have an elaborate courting ritual, which begins with a male approaching a female and calling from different branches until he is near her. Then, he begins swiveling his head, bobbing his body, and winking. If she accepts him, she will approach and touch her bill to his. Finally, the pair will begin to preen each other.

Eastern Screech-Owls usually mate for life but will accept a new partner if their previous one dies. Pairs are usually monogamous; however, males will occasionally mate with two females. Eggs are laid almost exclusively in tree cavities on a bed formed by accumulated wood shavings. After roughly 26 days of incubation, the young hatch.

These pint-sized owls live in Vermont year-round and only travel outside their territories when food shortages occur. If you’re hoping to spot an Eastern Screech-Owl, head to the forested areas where they primarily live and hunt. You can often locate them and other raptors by following mobbing behavior and the warning calls of small songbirds, Blue Jays, and crows. Keep an ear out, and you may find an Eastern Screech-Owl!

Subnivean Zone Tunnels © Jack Widness
Subnivean Zone Tunnels © Jack Widness

The Subnivean Zone

By: Julia Pupko

The subnivean zone is a network of tunnels and openings beneath the snow where animals, particularly small mammals, shelter during winter months. Parts of the subnivean zone develop as snow builds up on rocks, shrubs, and vegetation, leaving small, open pockets under or beside these features. As the snow thaws and freezes, a hardened shell forms, protecting these pockets from further snow accumulation.

Other parts of the subnivean zone form during a process called sublimation. As snow falls, it insulates the ground, which is usually a bit warmer than the ambient air temperature. While snow continues to accumulate, a small cavity forms where the ground and snow meet. Here, snow directly transforms into a gas and refreezes on the snowpack above. This condensed, frozen moisture creates a hardened layer of ice, which prevents the cavity from being filled with snow.

Many small mammals, such as shrews (family Soricidae) and lemmings and voles (family Cricetidae), remain active throughout the winter. As they move around and feed, they utilize both pockets and sublimated areas, building tunnel networks that connect these areas. The layer of snow above them provides insulation from bitter temperatures, keeping the subnivean zone around 32 degrees Fahrenheit. Additionally, some bird species, such as Redpolls (Genus Acanthis), Chickadees (Genus Poecile), and Grouse (Genus Bonasa) will spend the night under the snow, either above or within the subnivean zone.

Cold temperatures and food shortages are not the only fatal obstacles that face small mammals using the subnivean zone. Weasels (subfamily Mustelinae) and shrews use this zone as their hunting grounds. Weasels typically prey on shrews, voles, mice, and lemmings they come across in these tunnels. Meanwhile, shrews hunt other small mammals if other food sources are low. Additionally, foxes, coyotes, martens, and owls stalk subnivean zone inhabitants from above, diving in when they locate a snack with their keen hearing.

Climate change also threatens the survival of subnivean zone inhabitants. This area cannot readily form unless at least six inches of snow accumulate. Inconsistent snow pack exposes these small animals to colder temperatures, which can increase mortality rates. Increased thaws during the winter can also flood the subnivean zone, leading to increased mortality.

Coyote pup © Nathaniel Sharp
Coyote pup © Nathaniel Sharp

Companion Howls

By Julia Pupko

If you go for walks late at night or live in a rural area, you may hear more coyote yips and howls than usual this month. That is because February falls right in the middle of the coyote breeding season. Like many species, coyotes’ breeding season leads to changes in their behavior. During this time, you will typically hear vocalizations among mates and nuclear family units as they re-establish their territory and communicate with each other.

During breeding season, female coyotes who have just reached sexual maturity frequently find themselves surrounded by prospective mates all vying for their attention. The males usually play with a prospective female, sometimes bringing her gifts. Once a female picks her mate, other males typically back off with little encouragement. A monogamous species, coyotes remain together once bonded and maintain their territory. Males are very protective of their mate and usually guard her both when she is in heat and gives birth.

Once the young have matured, they either disperse or stay in their home range. For those that remain at home, typically only the alpha male and female breed. The rest stay in their parents’ territory and help defend food resources and protect the den. When females are 10 years old and males 12, they typically stop reproducing and either remain with their family unit or become solitary for the remainder of their lives.

Make sure to record any coyotes you hear or photograph any you see, and add your observations to the Vermont Atlas of Life on iNaturalist!

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Turkey Vulture gliding back to Vermont © Nathaniel Sharp
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Red-winged Blackbird © Nathaniel Sharp

Winter Specialties, Early Migrants, and Uncommon Holdovers

By Nathaniel Sharp

Throughout the state this winter, Vermont eBirders have been keeping tabs on the bird species they see in their backyards, neighborhoods, and local natural areas. The month of February provides Vermont with a mix of species that signal the very early beginnings of changing seasons. This year in particular finds us in the midst of a winter finch invasion, with Common Redpolls, Evening Grosbeaks, and Red-breasted Nuthatches (not a finch, but we’ll let that slide) descending on bird feeders across the state. Unless food sources run out, expect these birds to stick around through the month. And, pay close attention to those Common Redpoll flocks for the lighter, larger, and more northerly Hoary Redpoll, a big-time rarity most years that has been appearing with surprising regularity this winter.

February also sees the arrival of some of the earliest spring migrants, such as Red-winged Blackbirds, Brown-headed Cowbirds, Turkey Vultures, and even the earliest of the American Woodcocks, a rotund and recognizable harbinger of spring. Unusually, several of these species normally associated with spring’s arrival have managed to stick around through the winter, visiting bird feeders and finding whatever open water is available. Red-winged Blackbirds, Brown-headed Cowbirds, and even Rusty Blackbirds have been surprising birders who normally expect to see these species in late February. Birders in the Burlington area have even sighted a family of Black Vultures overwintering; this more southern vulture species was documented nesting for the first time in the state last summer.

Will these overwintering birds be joined by southern migrants earlier than usual this year, or are they simply hardy outliers? Only continued documentation of trends like these through the community science network of Vermont eBird will help us learn more about these interesting phenomena. As you wander the woods or watch your backyard bird feeders this month, keep an eye and ear out for this month’s unique mix of hardy winter birds and brave early migrants.

Groundhog (Marmota monax) Dave Fletcher – www.flickr.com/photos/dfletcher/
Groundhog (Marmota monax) Dave Fletcher – www.flickr.com/photos/dfletcher/

Shadows and Sex

By VCE Research Associate Bryan Pfeiffer

You didn’t need Punxsutawney Phil to know which way the wind blew on February 2. Groundhog Day isn’t about shadows. It’s about romance.

Birds and rodents are beginning a season of foreplay. February 2 is indeed significant. It falls about halfway between the Winter Solstice and the Spring Equinox, a period celebrated in various ways in human traditions from Paganism to Christianity. It seems also to be something of a turning point for wildlife, much of which has to do with the light: there’s more of it. VCE Research Associate Bryan Pfeiffer explains on his blog.

White-winged Crossbill on a salty roadway © Nick Tepper
White-winged Crossbill on a salty roadway © Nick Tepper

A Salty Situation

By Julia Pupko

While I was cruising down I-91 the other day, I could not help but notice a bunch of American Crows snacking on the side of the road. At first glance, it appeared that they were simply picking at the snow. If I had been able to stop and examine the situation with greater care, I am sure that I would have discovered their actual snack—road salt.

Road salt, or rock salt, is typically halite, the unpurified version of table salt (sodium chloride (NaCl)). Since it still contains impurities, it often looks like coarsely ground rocks. Several bird species—particularly those in the family Fringillidae, including Purple Finches, Pine Siskins, and Grosbeaks—are highly attracted to road salt. This may be because it looks like grit, or small, crushed stones that many birds ingest to help grind up food in their crop. Birds do not have the same capacity to metabolize salt as mammals, which means that they are susceptible to salt toxicity. Ingesting too much salt may be fatal, but it is difficult for researchers to retrieve bird carcasses from the wild to determine the prevalence of salt toxicity deaths. However, eating roadside salt poses another risk—car collisions. Researchers have dubbed road salt a “fatal attraction” for birds because they often get hit by speeding cars when flying in to feed.

Birds are not the only organisms that have to worry about road salt. Many trees and plants near roads suffer from increased salt levels. If you have ever passed a stand of browning conifers when traveling on roads that receive heavy salt loads, know that excess salt probably contributed to their condition. Salinization of surface waters near major roadways is also deeply concerning for the health of aquatic ecosystems. Amphibians such as Spotted Salamanders are highly sensitive to increased salt levels and can experience high mortality levels if they try to reproduce in surface waters that are too close to salty roads. Even humans can be affected. Road salt does not decompose after being dumped—only dilution reduces its potential impact. However, this rock salt solution can leach into groundwater and other drinking water supplies, negatively impacting kidney, liver, and cardiovascular health over time.

On a more upbeat note, many agencies are taking the dangers of rock salt seriously and exploring alternative options to keep people and wildlife safe. Travel with care this February, and watch out for ice and wildlife alike!

Crows Come Home to Roost

By Kent McFarland

With the sun dropping below the hills, the chase was on. The crows had gathered by the hundreds behind the store fronts in West Lebanon, New Hampshire. They’d streamed in from all directions, calling loudly on arrival. Some perched in sumac trees and picked at the seeds. Others cried out on our approach. Then, without warning, they were off. The game was afoot!

We followed them as best we could, zig-zagging through traffic and city streets, as they streamed from the pre-roost towards their final destination. With the light fading fast, we found them. Thousands of crows, with more arriving by the second, gathered in the trees and on the ground. Sometimes swirling up into the air over our heads in a great cloud of black birds, then settling down again in the trees with a cacophony of calls.

Join us on Outdoor Radio as we track down a huge winter crow roost and talk about why these amazing birds gather in such large flocks. We’ll even talk about why they are sometimes called a murder of crows.

Comments (5)

  1. Ted Jastrzembski says:

    I always look forward to the Field Guide, the writing is first rate, as it is for all the VCE publications. Who knew that coyotes were mostly monogamous? And those hordes of crows in West Leb gathering for cocktails?

  2. Nice job, Julia. Well written and researched.

  3. Marcia Haas says:

    Love the monthly newsletter and field guide to the month! I’m not a VT resident but most of the articles are also applicable to Massachusetts. Thanks so much!!

  4. Kit Allen says:

    Always learn SO much from these newsletters!
    THANK YOU!

  5. Liz Blum says:

    Thank you Julia. So well written. I am sending this to my 8 year old granddaughter to read and watch. She loves learning about wild animals.

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