William Freedberg

About William Freedberg

Studies indicate that Will Freedberg occupies the ecological niche of a semi-nocturnal generalist. His habits change seasonally, doing fieldwork and bird surveys in the summer, but also blogging, coordinating volunteers, taking photos, and doing background research. Life history traits include growing up in Boston and reluctantly graduating from Yale College. Behavioral research shows that William occasionally migrates to the tropics to seek out Hoatzins, pangolins, and sloths, but mostly socializes with his age cohort in urbanized areas of eastern North America. He is short-sighted, slow to react, and a poor swimmer.

Most bird species overwinter in the same general area from year to year. Not so with some finches. Around eight species of winter finch become nomadic in winter, sometimes crossing the continent in search of food.

One reason these birds don’t stick to an annual pattern is the annually shifting availability of their favorite foods. If conifer seeds and mountain-ash berries are abundant in Canada, winter finches stay put on their northern breeding grounds. In less fruitful years, they head off in search of their next meal.

Biologists and birders in Canada who keep track of seed availability are forecasting that this will be a good year for finch movements. Here’s what to look for this winter.

Purple Finches

Purple Finches had a great breeding season in Canada, in part due to an outbreak of spruce budworm, their go-to summer food. But the new hordes of yearling birds will need more seeds and berries than what’s available this winter in the north, and we’re already seeing a big movement of them in Massachusetts.

At feeders, Purple Finches love to eat safflower seed, but they’ll also stop for black-oil sunflower and thistle seed. Unlike the similar-looking House Finch, Purple Finches have a reddish wash that extends all the way down their wings and back, and a thicker bill.

Pine Siskins

Pine Siskin. Photo © Terri Nicker — Pine Siskin © Terri Nicker

Siskins are the stars of the show so far this year. Pine Siskins have arrived early in Massachusetts in spectacular numbers (with some observers recording overhead movements of more than 2,000!) At feeders, these finches don’t stop for much other than thistle seed, or other seeds small enough for their narrow bills.

Evening Grosbeaks

Evening Grosbeak © Jim Renault — Evening Grosbeak *© Jim Renault*

These bold-colored finches last irrupted into Massachusetts in 2018, a bit more recently than the other two finches on this list. Major irruption years were infrequent in the 1980s through 2000s, so it’s a pleasant surprise to see these birds again just two years after their last big movement through the region. At feeders, these thick-billed birds prefer larger seeds, like black-oil sunflower.

Bonus species: Red-breasted Nuthatches

While not technically a finch, this species is nearly as nomadic. Red-breasted Nuthatches are year-round residents in high-elevation coniferous forests, and normally, they only visit the rest of the state in winter. But this summer and fall saw several big pushes of Red-breasted Nuthatch into Eastern Mass as well, and it’s a real possibility that they’ll continue through the winter in great numbers.

All of these species have arrived earlier than in most irruption years. That leads to a question of whether or not they’ll persist all winter in Massachusetts. It’s possible that these birds are mostly transients on their way even farther south: feeder-watchers are reporting that flocks of winter finches are showing up for a day and leaving, and grosbeaks and siskins have already been reported as far south as the Gulf Coast.

This is a great winter to hang up some feeders and see what happens!

Hawks, falcons, and vultures are among the few groups of birds that migrate during the day.

Unlike songbirds and waterfowl, which migrate under cover of night, raptors are actually visible as they make their long journeys across continents.

Although hawks pass by some sites by the hundreds or thousands, that doesn’t necessarily mean you can see them from any site on any day of the season. To find your best day and destination, you have to think like a hawk.

Red-tailed Hawk copyright George Brehm — Red-tailed Hawk © George Brehm

Riding the Airwaves

Raptors have one goal when migrating: use as little energy as possible to make it to their destination. So, they seek out rising air currents to help them gain altitude without flapping.

Air rises as it is heated by the warmth of the ground (a “thermal”), or pushed upwards by passing over a hill or mountain (an “updraft”). Raptors circle inside these columns of rising air as it carries them upwards. As the air cools and stops rising, raptors exit and glide for miles, slowly losing altitude until they find another column (or start flapping).

Hawks often end up riding the same air current together, forming a rising spiral of birds, or a “kettle.” Kettling isn’t actually a social behavior, even if it looks like the hawks are flying together. Thermal-surfing raptors are simply taking advantage of the most efficient route, like drivers on a highway.

Cool Weather, Hot Hawkwatching

Thermals are strongest when the ground is much warmer than the air. Hawkwatching can be excellent when a cold front moves through, bringing cold air over the (temporarily) much warmer ground and sending thermals spiraling upwards.

Cold fronts are often accompanied by winds from the north, which are conducive to southbound raptors in the fall. When clear, cold air moves in from the north after many days of poor migration conditions (either rain or strong winds from the south), unusually high numbers of restless raptors can be seen migrating at once.

Timing is Everything

Mid-September is prime season for viewing Massachusetts’ most numerous and conspicuous raptors, like Broad-winged Hawks and Ospreys, as well as less common species like American Kestrels and Sharp-shinned Hawks. As the season cools, the mix shifts a little, but the hawkwatching often stays good until late October and tapers off into November.

A Mass Audubon Blog

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