The timing and distribution of birds in the winter can be remarkably different each year. I wrote recently about how we need help documenting birds this winter for the Maine Bird Atlas. I gave common redpolls as an example from the last few years and how food availability has greatly affected their distributions. So it was timely when Peter Shaw from Falmouth wrote to ask about the lack of dark-eyed juncos, saying he hasn’t seen a single one this year. These are not irruptive species, like the redpolls, so why the variation?

A fun place to start in thinking about a junco’s range is with a field guide. Pull out that old Peterson’s or dust off David Sibley’s guide to eastern birds and flip to the “range map” of a dark-eyed junco. (If your book is old enough, it may be called a “slate-colored junco.” Several of the subspecies across the United States used to be treated as their own species, but were then lumped together as one in the 1980s, and are now known as dark-eyed junco.) Focusing in the east, most books tend to show all of Maine as some shade of purple or another color to represent that they are year-round residents. This can often surprise people, especially in southern Maine, since we tend to only see juncos in the winter. That doesn’t mean they’re not here.

One of my favorite aspects of the Maine Bird Atlas is the fine scale maps that we are producing that show the breeding and wintering ranges of Maine birds. The juncos are a great example of how a “resident” species can have very different distributions (and needs) within our borders. The habitats that juncos use in the breeding season tend to be spruce-dominated – typically what we think of as boreal habitat – and especially found at higher elevations. There are also patches along the coast where you can find spruce-covered peninsulas and islands that juncos also breed along, making for a fairly unique breeding distribution map (and one of my favorites to quiz birders with).

Outside of the breeding season, juncos appear to have an altitudinal migration, leaving the mountain slopes for lower elevations, and often appear in our backyards. Their arrival in our yards typically coincides with the first snow, giving them the colloquial name of “snowbirds” and getting us back to Peter’s original question: where are they? Depending on when you’re reading this, maybe the appropriate question is where is the snow? Or, if it has snowed in your yard, are you seeing juncos now?

While juncos have descended into our neighborhoods, with migration peaking in October, they may not be as detectable by the average onlooker until they arrive at our feeders. So far this fall and early winter, juncos have been around in the same abundance and frequency as past years – we can check thanks to projects like Cornell’s eBird, the same database we are using for the Maine Bird Atlas – but with the lack of early snow on the ground, they are taking advantage of the abundance of natural food while it is easy to find. As we often say each fall, “leave the leaves” on the ground because it provides food (and shelter) for many animals, and dark-eyed juncos are one of those. I’ve been watching a flock of about eight to 12 juncos that arrived the third week of October (right on time for my Windham yard), that make a near-daily afternoon stop to kick around the leaf litter and forage on seeds. Most of the juncos currently in Maine are doing just that, finding the naturally occurring food, which is often a better, more nutritious source of food than seeds we are providing in feeders. Once the snow covers most of it, they’ll be at your feeders, taking advantage of an easy meal.

In sum, those juncos are out there; just keep an eye out as the ground gets snow-covered for them to make their way to your feeders. While I’ll admit my sample size is way too low and very biased by effort, I helped with the Greater Portland Christmas Bird Count on Dec. 18, mostly counting birds around Scarborough, and we had about a dozen juncos in a small snow-covered section. The following day, I helped with the York Christmas count, where there was no snow, and we struggled to find many songbirds and only had one junco in our section. It’ll be fun to compare the counts once all the data comes in, so stay tuned for highlights from those.

CUTWORMS EVERYWHERE

Juncos aren’t the only critters that are easier to detect when it snows. So are cutworms! I’ve written about insects that stay active in the winter in the past (Ask Maine Audubon, Feb. 2022) and mentioned the large yellow cutworm (aka “winter cutworm” or simply Noctua pronuba), but it’s worth mentioning again because they are being seen and reported in huge numbers lately.

If you’re on the Maine Wildlife Facebook group, you probably saw the handful of reports after the Dec. 17 snowstorm, some with “hundreds” of cutworms reported crawling across the top of the snow. There was definitely some confusion, at least at first, about what the species were, so I thought I’d clear up any misconceptions here. Generally, if you see a caterpillar on the snow in winter, it is going to be the aforementioned cutworm. These non-native cutworms overwinter in a late-larval stage (think big caterpillar).

There were suggestions that these were winter moths (because “winter,” right?), but those we typically see as late-season flying adults (think winged moths) that are taking advantage of nights when most predators are gone and they’ve got a very small window of opportunity to find a mate. It is worth noting that the non-native, invasive winter moth (Operophtera brumata) is visually identical to the native Bruce spanworm (Operophtera bruceata), so while the former is a spreading problem, keep in mind that there is a native species we may also (or instead) be seeing that is a part of the ecosystem. And lastly, browntail moth is the other highly-hated and also non-native lepidoptera of winter, except these typically overwinter as early stage larvae (think tiny caterpillars) in their silky nests at the top of deciduous trees. These aren’t likely to be active until the spring, making winter a great time to snip any nests from trees. You’ll still need to be careful about contacting any of their skin-irritating body fibers.

Do you have a nature question for Doug? Email questions to ask@maineaudubon.org and visit maineaudubon.org to learn more about birding, native plants, and programs and events focusing on Maine wildlife and habitat. Doug and other naturalists lead free bird walks on Thursday mornings, 8 to 10 a.m., at the Gilsland Farm Audubon Sanctuary in Falmouth.

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