Tag Archives: birds

Skyline copyright Michael Mondville

One Way Light Pollution Impacts Birds

Skyline copyright Michael Mondville
Boston’s bright lights create a hazy glow on the horizon that can be seen for miles. Photo © Michael Mondville

Migrating birds are attracted to artificial light at night, and ornithologists are just beginning to understand how that affects their survival.

Recent studies show that the diffuse glow of entire cities can draw migrating birds towards them—and away from more suitable habitat.

There are already hundreds of records of mesmerized birds fluttering around single, isolated sources of bright light— from thousands of migrants trapped in the beams of mile-high searchlights in New York City, to dozens of warblers gathering at the windows of lighthouses.

But until recently, there was limited evidence for how light pollution across an entire region affects where migrants rest and feed.

Radar studies show “clouds” of birds near cities 

To test if birds gather disproportionately in brightly-lit cities, migration ecologists looked to doppler radar data. This is the same radar used to create weather forecasts across the country. Doppler radar reveals the density of particles in the air, whether it’s rain, birds, or aircraft, so it’s useful for remotely observing which areas migrating birds are using the most.

Naturalists might expect that migratory birds gravitate towards undeveloped areas, just as most do when they aren’t migrating. But this isn’t necessarily true, according to a team led by scientists from the University of Delaware.

In fact, radar signals consistently show more migrants pausing within a couple of miles of brightly-lit areas than anywhere else within around 30 miles. Migrant density peaks again 50-60 miles away, where the glow of lights on the horizon is dimmer or invisible.

These graphs show the density of migrating birds relative to major sources of light pollution like cities in spring (left) and fall (right) migration. Source: Cohen et al. (2020) (axis labels added).

This suggests that artificial light from cities is drawing in birds from greater distances than once believed. The authors of the study write that this pattern risks “impeding [birds’] selection for extensive forest habitat.” 

They go on to caution that “high‐quality stopover habitat is critical to successful migration, and hindrances during migration can decrease fitness.”

Prioritizing Urban Greenspaces for Birds

Migratory birds’ attraction to artificial light may be one reason behind the surprisingly excellent birding at greenspaces in cities—something birders have known about for a long time, but struggled to fully explain.

A canopy of trees meets Boston’s skyline, as seen from Mt. Auburn Cemetery in Watertown. Source: Wikimedia commons

Take Mount Auburn Cemetery, for example: it’s arguably the most famous site in the Northeast to see big numbers of warblers in spring. New York City’s Central Park, too, offers excellent birding that can rival—or outmatch—spring migration in intact forests.

But despite their attraction to the bright glow of cities, birds face increased hazards in urban environments. Most migratory birds feed exclusively on insects, which are harder to come by in cities, and urban ecosystems host more predators per square mile than other habitats.

Modifications as simple as planting native species, reducing insecticides, adding understory and mid-story habitat, or controlling predators could give migrants a much-needed boost at these sites. As long as light pollution continues to be an issue, improving urban habitat and reducing hazards remains important work.

A Harlequin Duck in Western Mass: Out of Place, or Right at Home?

Harlequin Ducks may not be the rarest ocean-going duck in Massachusetts, but they require a more specific habitat than any other kind of waterfowl: rocky, jagged coastlines with rough surf and abundant shellfish.

In fact, according to eBird, nobody had ever documented Harlequin Ducks more than a couple of miles inland in Massachusetts—until New Year’s Day 2021 when a local birder found a first-year male Harlequin on the fast-flowing Millers River in Turner’s Falls, MA, more than 120 miles away from the coast.  

The rocky Millers River was apparently good enough habitat for this young male Harlequin Duck. Photo © James Smith
The rocky Millers River was apparently good enough habitat for this young male Harlequin Duck. Photo © James Smith

Powerful Rivers are Western Harlequins’ Summer Home

While it’s surprising to see this duck inland in Massachusetts, Harlequins in other parts of the country actually spend half of their lives on fresh water. In the Rocky Mountains and the Cascades of the West, these patchily-distributed ducks breed in fast flowing, whitewater rivers.

The Millers River is well-known among paddlers for its fast current and rough stretches. Not many rivers in Massachusetts have the wide expanses of rapids that Harlequins prefer, making the Millers a likely candidate for our first inland record of this species.

Even Wandering Birds Follow Habitat Guidelines

This sighting is a great example of how rigidly habitat preferences govern  where birds are found, even in cases when birds show up in unusual geographic regions.

Most vagrant birds (that is, birds outside of their normal range) also stick to their usual habitats, or the closest thing they can find. Massachusetts’ last sighting of a Tropical Kingbird, for example, showed up in the brushy fields of Rock Meadow in Belmont—a fair local approximation of the low plains a prefers in the extreme Southwest.

And, true to its name, a Barn Owl that strayed farther north than normal was spotted taking shelter in the rafters of a high-ceilinged wooden garage in Lexington.

Stay in the Know

If you’re interested in following along with the latest unusual sightings, check out our weekly rare bird reports!

Black-capped Chickadee at a Feeder

Why Cleaning Bird Feeders Matters

Enjoying watching birds visit your feeder? Great! Make sure the birds that visit stay healthy by keeping your feeder clean.

Black-capped Chickadee at a Feeder
Black-capped Chickadee at a Feeder

Why a Clean Feeder is a Happy Feeder

High concentrations of birds in close proximity to one another can contribute to the spread of disease at bird feeders. The four diseases that most frequently affect birds that use feeders are: salmonella, trichomoniasis, aspergillosis, and avian pox.

All of these diseases are transmitted from one bird to another at feeding stations, especially when overcrowding occurs. Birds are also susceptible to mites and lice. There are many steps you can take to help keep feeder birds and people safe and healthy.

How to Keep Birds Healthy

  • Clean feeders monthly using one part bleach to nine parts warm water. Soak the feeder in the solution for a few minutes, rinse, and air dry.
  • If uneaten food is accumulating in or under feeders, consider using less food or switch to a seed more to the birds’ liking.
  • If birds are fighting over space at a feeder, consider adding more feeders to alleviate the congestion that can potentially be responsible for the rapid spread of disease.
  • Store seed in airtight containers to prevent spoilage.
  • Avoid throwing large amounts of food on the ground or alternate ground feeding areas so that uneaten food does not accumulate and develop bacteria or mold.
  • If dead birds are found, stop feeding for a few weeks and thoroughly clean feeders and areas under feeders. Use disposable gloves when handling dead birds.

Learn More

Get answers to bird feeding frequently asked questions. Still have questions? Ask our wildlife experts.

Dark-eyed Junco © Eladi Bermudez

Take 5: Whatcha Gonna Do With All That Junco?

If you enjoy watching birds at feeders, there’s a good chance you have a soft spot for these little darlings of the winter bird feeder crowd: Dark-eyed Juncos.

Although there are juncos to be found in Massachusetts year-round, these “snowbirds” are most recognizable hopping around on the ground or in the snow beneath seed feeders, often in small flocks. These ground-feeding sparrows love to snap up fallen seeds in their cone-shaped pink bills, which contrast sharply with their dark grey or brown upper plumage. Their white outer tail feathers will flash into view when they take flight.

Many juncos spend the breeding season to the North of us, across much of Canada, flying south and spreading out across North America the rest of the year, although some will stay year-round and retreat to the woods or higher elevations as the weather warms.

Enjoy these five photos of Dark-eyed Juncos from our annual Picture This: Your Great Outdoors photo contest and look for them on your next winter walk in the woods!

Dark-eyed Junco © Rob Cardinale
Dark-eyed Junco © Rob Cardinale
Dark-eyed Junco © Andy Eckerson
Dark-eyed Junco © Andy Eckerson
Dark-eyed Junco © Dan Harrington
Dark-eyed Junco © Dan Harrington
Dark-eyed Junco © Jim Feroli
Dark-eyed Junco © Jim Feroli
Dark-eyed Junco © Eladi Bermudez
Dark-eyed Junco © Eladi Bermudez
Snowy Owl © Paul Malenfant

Take 5: Superb Snowy Owls

They’re here! Snowy Owls have arrived from their breeding grounds in the Arctic and can be spotted at Plum Island, Duxbury Beach, and other open, treeless areas near the coast through March—if you make the trip to see Snowy Owls this winter, please protect these beautiful raptors by viewing them from a safe and respectful distance at public sites and do not approach them.

Norman Smith, the former director of Mass Audubon’s Blue Hills Trailside Museum, is keeping busy in his retirement by continuing his Snowy Owl rescue and research efforts: The first report of a Snowy Owl at Logan Airport this season came in on November 5, so he hurried down to capture the owl, take some measurements and research notes, and release it at Duxbury Beach.

Norman reports that it was a healthy “hatch-year” bird (meaning it was born this past summer), which suggests there was good breeding this year in the region of the Arctic where this particular owl was born. Historically, since he started with the Snowy Owl Project in 1981, Norman would capture almost all hatch-year birds, but the past several winters saw predominantly adults arriving in Massachusetts, a poor sign for breeding success. Norman says his colleagues in Greenland reported their best breeding year since 1998 this past summer, while others in Barrow, Alaska, reported no breeding at all, so it can vary dramatically by location due to a number of factors, including climate change.

Snowy Owls predominantly feed on rodents called lemmings, so the success of lemming populations affects Snowy Owl populations: when there’s a boom in lemmings, we see a rise in the number of hatch-year owls traveling south. Lemmings are now facing increased pressure from climate change, such as rising temperatures, milder winters, shifting weather patterns, and changes in vegetation, which makes breeding success more difficult. So a decline in hatch-year Snowy Owls can signal climate impacts across entire food chains.

Enjoy these five photos of Snowy Owls from our annual Picture This: Your Great Outdoors photo contest, then visit our website to learn how you can support our work to monitor and protect these beautiful birds and where and how to observe Snowy Owls yourself.

Snowy Owl © A. Grigorenko
Snowy Owl © A. Grigorenko
Snowy Owl © Jenny Zhao
Snowy Owl © Jenny Zhao
Snowy Owl © Paul Malenfant
Snowy Owl © Paul Malenfant
Snowy Owl © Sara Silverberg
Snowy Owl © Sara Silverberg
Snowy Owl © Karen Walker
Snowy Owl © Karen Walker
Pine Siskin. Photo © Terri Nicker

Siskins and Grosbeaks and Purple Finches, Oh My!

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 Finch
Purple Finches have more extensive color and a different shape than similar House 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

Red-breasted Nuthatch
Red-breasted Nuthatch

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!

Golden-crowned Kinglet © Ken Lee

Take 5: The Littlest King

Small but mighty, kinglets are barely bigger than hummingbirds, weighing less than half an ounce, and yet they are still capable of surviving in remarkably cold environments, in some regions overwintering in places where nighttime temperatures can fall below 0°F. Their preference for the upper canopy of thick stands of tall conifers, especially spruce and fir, coupled with their diminutive size, makes them difficult to spot, but fall migration is likely your best chance.

Both Golden-crowned and Ruby-crowned kinglets are migrating from northern forests to their wintering grounds and passing through Massachusetts this time of year, but only individuals of the golden variety tend to linger beyond the fall migration period. You’ll need a keen ear to pinpoint the very piercing call of the male Golden-crowned Kinglet, which is so high-pitched that some older birders find that they lose the ability to hear the highest notes as they age.

Here are five photos of “kingly” Golden-crowned Kinglets from our annual Picture This: Your Great Outdoors photo contest.

Golden-crowned Kinglet © Ken Lee
Golden-crowned Kinglet © Ken Lee
Golden-crowned Kinglet © Claudia Carpinone
Golden-crowned Kinglet © Claudia Carpinone
Golden-crowned Kinglet © Davey Walters
Golden-crowned Kinglet © Davey Walters
Golden-crowned Kinglet © Mary Keleher
Golden-crowned Kinglet © Mary Keleher
Golden-crowned Kinglet © Nathan Goshgarian
Golden-crowned Kinglet © Nathan Goshgarian
Song Sparrow © Thomas Kilian

Take 5: A Song in Your Heart

“A bird doesn’t sing because it has an answer, it sings because it has a song.”

Maya Angelou

The Song Sparrow is a welcome visitor to fields, farms, parks, and gardens throughout Massachusetts. One of the first birds that many novice birders learn to identify by sound, the aptly named Song Sparrow may be heard singing its bright and cheery song from sunup to sundown from spring to fall.

The Song Sparrow took home the title of “most widely distributed bird” in Massachusetts in both of our Breeding Bird Atlas surveys. While many sparrow species are struggling to maintain their numbers, the irrepressible Song Sparrow seems to be holding its own. Its massive breeding range, adaptability, and ready use of almost any open or semi-open habitat have helped the species remain practically ubiquitous even in the face of suburbanization and other major landscape changes. Still, despite the stability of its breeding footprint, the Song Sparrow has demonstrated significant declines in overall abundance over the last half-century, suggesting a need for continued monitoring and conservation efforts.

While Song Sparrows can be found in Massachusetts year-round, you may see an uptick in their numbers in the fall as migrants pass through from their northern breeding grounds on their way to warmer places to over-winter. Look for a streaky sparrow perched on low shrubs in open, scrubby, often wet areas, pumping its tail in flight as it flits from bush to bush, and listen for the clear, crisp notes of the colorful repertoire of songs for which it is named.

This is your last chance to enter the 2020 Picture This: Your Great Outdoors photo contest! The deadline for entries is September 30, so enjoy these five submissions from past years and send us your own nature photography today!

Song Sparrow © Amanda Altena
Song Sparrow © Amanda Altena
Song Sparrow at Waseeka Wildlife Sanctuary © Charlene Gaboriault
Song Sparrow at Waseeka Wildlife Sanctuary © Charlene Gaboriault
Song Sparrow © Thomas Kilian
Song Sparrow © Thomas Kilian
Song Sparrow © Lucy Allen
Song Sparrow © Lucy Allen
Song Sparrow © Cristina Hartshorn
Song Sparrow © Cristina Hartshorn
Red-tailed Hawk copyright George Brehm

Fall Hawk Migration is in the Air

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.

If you want to plan a trip to see migrating raptors this season, check out our list of hawkwatching sites as well as resources from the Eastern Massachusetts Hawk Watch club.

American Goldfinch © Mark Uchneat

Take 5: Go For the Goldfinch

Out of the corner of your eye, a sunny, cheerful flash of bright yellow alights upon your bird feeder and almost certainly means one thing: the American Goldfinch!

Almost exclusively seed-eaters, the so-called “wild canaries” of the Americas are late nesters relative to most of our breeding birds here in Massachusetts, giving them access to nutritious native thistle seeds to feed their young. Known for their energetic seed-harvesting acrobatics, look for them plucking thistle seeds this time of year and listen for their sweet, enthusiastic song, a long, fluctuating string of warbles and twitters. They are also known to make contact calls, often mid-flight, the most common of which bears the mnemonic phrase po-ta-to-chip.

Before you know it, the arrival of cooler weather will turn the vibrant yellow males’ plumage a drab brown until the arrival of spring and the return of the breeding season, so enjoy the cheery colors while they last, but the varied sounds and acrobatic antics of these beloved birds can be appreciated year-round in virtually every part of the state.

Here are five photos of fabulous goldfinches to brighten your day. We want to see your nature photos, too! Enter the Picture This: Your Great Outdoors photo contest by September 30

American Goldfinch © Mike Iwanicki
American Goldfinch © Mike Iwanicki
American Goldfinch © Sarah Keates
American Goldfinch © Sarah Keates
American Goldfinch © Karen Karlberg
American Goldfinch © Karen Karlberg
American Goldfinch © Mark Uchneat
American Goldfinch © Mark Uchneat
American Goldfinch © Anindya Sen
American Goldfinch © Anindya Sen