Frosted summits
© Kent McFarland
Although the days are slowly growing longer, life in the Northeast now finds itself in the coldest depths of winter. January is about survival. Wildlife that doesn’t migrate adapts instead in order to make it to spring. Here are a few tidbits of natural history happening outdoors this month around you.
By Julia Pupko
Although January is cold and lacks the migratory bird species who breed in Vermont, winter birding can still be quite eventful. Not all migratory species head to the balmy southern United States, Caribbean, or Central or South America during the winter. In fact, some species who typically reside north of Vermont actually consider the Green Mountain State an ideal winter destination. These species are called irruptive species, or species whose population density can shift quickly. Irruptive bird species move south when winter food supplies are dwindling in their usual range, meaning that not all of them visit Vermont on an annual basis and that population densities here are dependent on food levels in other parts of these species’ ranges.
Winter finches (family Fringillidae) are one group of irruptive species that are commonly found in Vermont during the winter. This group includes Pine Grosbeak (Pinicola enucleator), Common Redpoll (Acanthis flammea), Pine Siskin (Spinus pinus), and Evening Grosbeak (Coccothraustes vespertinus), all of which have been sighted in Vermont over the past week. During this time of year, all of the aforementioned species can be found foraging in flocks and all may be found at backyard bird feeders during the winter. When they are not at bird feeders, Pine Grosbeaks can be found in mixed forests, foraging for seeds. Evening Grosbeaks are beautiful yellow, black, and white birds, which can be found darting through the higher elevation forests. Pine Siskins utilize conifer seeds or seed heads of herbaceous species in fields. Common Redpolls are sometimes found in flocks numbering in the hundreds, usually in meadows with herbaceous plants bearing seed heads.
Keep your eyes open for these species this month! Make sure to report your findings to Vermont eBird.
By Julia Pupko
While many mammal species hibernate during the winter, species in the Mustelid family, such as American Minks (Neogale vison), remain active. If you frequently walk near any streams, rivers, marshes, or lakes, there is a good chance that you could spot a mink this month.
Minks live in burrows, often those created then abandoned by muskrats or beavers, near permanent bodies of water. They hunt on land and in the water, preying on small mammals, waterfowl, marsh-nesting birds, fish, crayfish, and aquatic beetles. During the winter, mink rely more heavily on small mammals and any aquatic organisms they can find. American Mink are superb swimmers, assisted by their partially-webbed feet and oil-coated, water-repellent fur. Minks are typically solitary, yet are rather playful. You may catch them sliding down snow-covered slopes on their belly, or running then sliding across frozen surfaces. While minks are primarily active during dusk, night, and dawn, they can also be found during the day. Your best chance of spotting one is likely at dawn or dusk.
If you do encounter a mink, or any signs of its presence, please share a photo of your observation with the Vermont Atlas of Life on iNaturalist!
By Julia Pupko
During the dead of January, when the cold makes your nostrils freeze together with each breath, I often find myself spending more time indoors, keeping my nostrils well-heated. I often use this time to delve into new topics and spend time on iNaturalist, identifying observations. The Identify feature of iNaturalist (found in the top banner of the browser version of iNaturalist, next to the Community tab) allows users to easily filter observations and identify those which they can identify. On eButterfly, the Identify feature works in a similar manner. Identification of observations on iNaturalist and eButterfly is very important—community identifications provide a form of data quality control, confirming the identity of the organism in question. Once two-thirds of identifiers have agreed with an identification, the observation becomes Research Grade. The metadata from Research Grade observations are pulled into databases such as the Global Biodiversity Information Facility (GBIF), allowing researchers and community naturalists alike to easily download data from multiple sources for analysis.
In Vermont, there are over 723,600 verifiable observations of 9,812 different species on iNaturalist. Of these observations, 473,865 are Research Grade, leaving 249,823 observations that have yet to be identified. iNaturalist is a valuable resource for occurrence data, providing the platform for community contributions to many of the Vermont Atlas of Life wildlife atlases. To use this data in our analyses, and for these data to be most useful for you, among other community naturalists and researchers, these observations need to be Research Grade.
However, identifying hundreds of thousands of observations is an impossible task without many helping hands. This month, the Vermont Atlas of Life team would like to challenge you all to an ID-off: who can identify the most observations during the months of January and February on iNaturalist and eButterfly?
For those who may be unfamiliar with iNaturalist’s Identify feature, it is easy to use. Click the Identify tab in the top banner of iNaturalist, and you will find a page similar to the Explore page. From here, you can filter observations by region, taxonomic group, date range, and more. Once you have filtered the observations to those you wish to identify, simply click on the first observation on the page. From there, you can easily agree with the current identification, suggest a new one, add comments or annotations, check out more information on the observation, view iNaturalist’s A.I. suggestions, and more. You can then navigate to the next observation using the arrow keys on the sides of the identify panel. In eButterfly, the Identify feature works in a very similar manner to iNaturalist.
For more detailed information on how to use the Identify feature of iNaturalist and eButterfly, visit the Identify Challenge page. At the end of the month, we will announce the winners of the challenge (with permission)—the iNaturalist and eButterfly users who has identified the most observations in the state of Vermont between January and February. Best of luck!
By Julia Pupko
As the winter months continue, I want to continue drawing your attention to the easily overlooked jewels hidden among the branches. If you happen upon willow trees this month, check the ends of their twigs. You may get an interesting surprise—a pinecone on a willow tree!
Of course, this is not a true pinecone. In fact, it is not a reproductive structure at all. It is a gall, or a growth caused by an insect or fungi, in this instance the Willow Pinecone Gall Midge (Rhabdophaga strobiloides). A female R. strobiloides will lay eggs near the buds on a willow twig, which hatch in two to three days, and bore through the base leaves of a bud, into the meristematic tissue. What happens next is a bit of a mystery. Either the female gall midge injects chemicals into the end of the twig, or the gall midge larva irritates the bud as it bores in. Regardless of the exact cause, a gall begins to form, with noticeable swelling occurring within two to four weeks of the larva hatching, creating a protective case and food source for the larva. The larva grows through the second and third instars through July, with the gall increasing in diameter through September. The Willow Pinecone Gall Midge spins a layer of silk around the main chamber of the gall during the fall, which it overwinters in until the spring. The larva pupates and emerges during the spring.
Interestingly enough, this willow parasitoid sometimes becomes prey by becoming a host itself. For example, female Gastrancistrus sp. inject their eggs through the gall tissue and into first instar R. strobiloides, using an ovipositor. The first Gastrancistrus sp. larva to emerge kills the other eggs and begins to grow in the R. strobiloides larva, overwinters, and then pupates in the spring. Other parasites, such as Torymus cecidomyiae, have a slightly different strategy—attacking R. strobiloides in early August, injecting one egg through the gall, onto a third instar R. strobiloides, and feeding externally for a few days. Torymus cecidomyiae will also feed on Gastrancistrus sp. larva, and can be considered facultative hyperparasitoids.
Keep your eye out for these interesting galls as you wander through the woods this January and make sure you share any observations to iNaturalist!
By Julia Pupko
When I poke my head outside my front door each morning, I immediately lay my eyes on a crab apple tree, still holding onto many of its fruits. Frequently, the tree is filled with Cedar Waxwings (Bombycilla cedrorum), among other species, munching on the fruits. However, this food source is not without its risks.
During the fall and winter, berries and fruits can ferment, and birds consuming fermented fruits and berries can get drunk. Freezing temperatures, followed by a thaw, can cause fruits and berries to ferment faster and become more potent. As a result, fermented fruits and berries typically attain their highest ethanol content in the spring, but changing winter conditions (with increased freeze thaw cycles) may cause more fruits and berries to become more potent over a shorter period of time. When birds eat too many fermented fruits or berries and become tipsy, they may fly into windows and other structures at higher rates, become more vulnerable to predation, fall straight out of a tree, or poison themselves with ethanol. Occasionally, flocks of Waxwings and other fruit-eating birds will experience a mass mortality event following the consumption of particularly fermented fruits or berries.
If you find a waxwing (or another bird that eats fruits and berries during the winter) that appears to be inebriated, chances are that it just needs some time to sober up and continue merrily on its way. Contact VINS or another wildlife rehabilitation center to determine what you should do if you find an inebriated bird that is unable to fly.
