Category Archives: Birds and Birding

ACT Season 2 Wrap-up

The Avian Collision Team is a volunteer effort to monitor bird-window strikes in downtown Boston. This fall was the second season, running from early August to mid-October. Volunteers walked 7 survey routes from Saturday to Tuesday between 6 and 9 a.m., finding a total of 74 individuals. This makes 193 total strikes between the fall and spring seasons. 

The volunteer process

Birds that were alive but injured, which was about a quarter of the time, were taken to Tufts Cummings School of Veterinary Medicine to be rehabilitated and released. Those that were deceased were collected and donated to the Harvard Museum of Comparative Zoology’s Ornithology department to be used as study specimen. 

Note: Mass Audubon’s volunteers collect specimen with a permit from the Division of Fisheries and Wildlife. It is illegal to collect birds under the Migratory Bird Treaty Act.

A Commmon Yellowthroat outside of University Hall at UMass Boston

Table 1 shows a preliminary roundup of the window-strike species found by ACT volunteers. Locations and images can be found on iNaturalist, where other citizen scientists around the world are submitting similar window-strike data on a project called “Bird-window collisions”.  

Table 1: Number of individuals of each species found by ACT

White-throated Sparrow. . . 23 House Finch. . . . . . . . . . . . . . . . 3 Black-billed Cuckoo. . . . . . . . . 1
Ovenbird . . . . . . . . . . . . . . . 22 Northern Waterthrush. . . . . . . 3 Yellow-billed Cuckoo . . . . . . . 1
Common Yellowthroat . . . . 19 Blackpoll Warbler. . . . . . . . . . . 3 Red-eyed Vireo. . . . . . . . . . . . 1
Hermit Thrush . . . . . . . . . . . 7 Northern Flicker . . . . . . . . . . . . 2 Blue-headed Vireo . . . . . . . . . 1
Black-and-white Warbler. . 7 American Robin. . . . . . . . . . . . . 2 Blue Jay . . . . . . . . . . . . . . . . . . 1
Lincoln’s Sparrow . . . . . . . . 6 Song Sparrow. . . . . . . . . . . . . . 2 European Starling . . . . . . . . . . 1
Magnolia Warbler. . . . . . . . 5 Nashville Warbler. . . . . . . . . . . 2 Cedar Waxwing . . . . . . . . . . . 1
American Redstart . . . . . . . 5 Chestnut-sided Warbler. . . . . . 2 Veery . . . . . . . . . . . . . . . . . . . . 1
Brown Creeper . . . . . . . . . . 4 Black-throated Green Warbler 2 Chipping Sparrow. . . . . . . . . . 1
Golden-crowned Kinglet . . 4 Canada Warbler. . . . . . . . . . . . 2 Clay-colored Sparrow. . . . . .  . 1
Dark-eyed Junco . . . . . . . . . 4 Indigo Bunting. . . . . . . . . . . . . . 2 Swamp Sparrow . . . . . . . . . . . 1
Savannah Sparrow. . . . . . . 4 Virginia Rail. . . . . . . . . . . . . . . . 1 Pine Warbler. . . . . . . . . . . . . . 1
Northern Parula . . . . . . . . . 4 Belted Kingfisher. . . . . . . . . . . 1 Black-throated Blue Warbler 1
American Woodcock . . . . . 3 Yellow-bellied Sapsucker. . . . . 1 Palm Warbler. . . . . . . . . . .  . 1
Ruby-throated Hummingbird 3 Red-bellied Woodpecker . . . . 1 House Sparrow. . . . . . . . . . . 1
Mourning Dove . . . . . . . . . . . 3 Red-breasted Nuthatch. . . . . . 1 Brown-headed Cowbird . . . 1
Swainson’s Thrush . . . . . . . . . 3 White-breasted Nuthatch. . . . 1 Baltimore Oriole . . . . . . . . . 1

Note: This list is still being updated as we finalize our data

As evident in Table 1, window collisions in downtown Boston during the times in which we survey are primarily migratory species. Much like moths to a light bulb, migrating birds are drawn to city lights during their nighttime migratory journeys. They land in cities and in the early mornings when they re-orient themselves and look for food, they fly into glass windows. Learn more about this hazard and how you can do something about it on Mass Audubon’s website

A Lincoln’s Sparrow at the John Hancock Tower

ACT will start again during spring migration, running its third season from April 11 – June 2. Sign up to be a volunteer and direct questions to kkeohane@massaudubon.org. 

Drumlin Farm is banding Massachusetts’ smallest owl – the Northern Saw-whet

A team of researchers measure the wing feathers on a Saw-whet owl at Drumlin Farm’s banding center. Handling owls is only legal with a government permit, and only by researchers trained to handle them safely.

Each year, Mass Audubon sanctuaries across the state set up banding stations to track Saw-whet owl migration. Drumlin Farm in Lincoln, Moose Hill in Sharon, and Daniel Webster in Marshfield all have dedicated crews of Saw-whet owl banders. November is the best time to find these tiny predators, as large numbers are passing through Massachusetts on their migration route.  

Saw-whets were an under-studied species 

At 7-8 inches long and weighing 2-5 ounces, Saw-whet owls are about the size of an American Robin. Because of their small size, Saw-whets are difficult to find. Many birders used to consider them a rarity, but in 1994 a study at Daniel Webster Wildlife Sanctuary revealed that these birds are much more widespread than previously thought. In fact, they are found in higher numbers than any other owl species in Massachusetts in the fall. 

Saw-whets are migratory 

Not only were these birds mistakenly thought to be a rarity, but they were also thought to be permanent residents. With anecdotal evidence as well as increased banding efforts, researchers have discovered that most of them do migrate, and can travel as far south as the Mexican border. Their migration routes, however, are less consistent and more unpredictable than other migrants, making them a complicated species to study.

A scientist holds a Saw-whet Owl with a “bander’s grip,” securing it’s talons in a way that’s safe and comfortable for both the bird and the human.

Banding efforts in the US 

In 1994, Project Owlnet was initiated as a way to bring together data from across the country and recruit new banding stations. Participating organizations share research and best practices to better understand these birds. The map below shows a map of owl banding stations that are a part of Project Owlnet. 

Mass Audubon sanctuaries contribute to this dataset by banding, weighing, and measuring Saw-whets. They also identify each bird’s age, sex, and take feather samples for DNA research. 

Fun fact: Saw-whet age can be determined with UV light 

The fluorescent color in young owl feathers comes from a pigment called “porphyrin,” which causes the feathers to appear red under UV lights. This pigment breaks down over time and exposure to light, so researchers can use this technique to identify an owl’s age. The pictures above show a second-year Saw-whet because they have clear pink hues in their newer primary feathers and on their coverts.  

Findings 

The map below shows banding stations in Massachusetts (yellow dots), Saw-whet owls from Massachusetts that were recaptured elsewhere (red dots), and Saw-whet owls banded elsewhere that were recaptured in Massachusetts (blue dots). Owls have been banded along their migratory route from as far north as Ontario and as far south as Maryland. 

Interested in seeing these owls for yourself? Join Mass Audubon at one of many upcoming nocturnal events. Happy owling! 

Dial-a-Bird: A Tribute to the Voice of Audubon

Before the internet age, informational phone lines were widespread— providing everything from weather forecasts, time of day, or even local rare bird alerts.

Mass Audubon started the original bird hotline in 1954 with some help from a telecom executive, Henry Parker, who happened to be an avid birder.

In fact, the system that Parker developed for the Voice of Audubon came before the widespread use of phone hotlines. The Dictaphone-based system he gave Mass Audubon eventually became the basis for other users to pre-record airline schedules, theater showtimes, and other, more general-interest uses.

The rarities hotline, called “The Voice of Audubon” or VoA, reduced the need for staff to recite sightings to every birder who asked—making it as much a boon for Mass Audubon as for the hundreds of birders calling in each week.

Making the Papers

Shortly after its introduction, the Voice of Audubon was incorporated every week into a bird sightings column in the Boston Globe.

Initially, non-birder Globe interns had to transcribe the bulletin entirely by ear, leading to some amusing misspellings of bird names—such as “wobbling vireos” instead of “Warbling Vireos, “dowagers” instead of dowitchers,” “dick sizzles” instead of “Dickcissels,” and a “pair of green falcons” instead of a “Peregrine Falcon.” Eventually, a written transcript was made available to anyone interested in printing the week’s bird sightings.

A group of photographers respond to a report of a rarity, in this case a Great Gray Owl in southern New Hampshire. Always be respectful of vagrant birds– particularly owls and waterbirds– by not approaching them.

Changing Tastes

The Voice of Audubon became a wildly popular model, with similar call-in lines eventually cropping up in most US states. The nationwide rare bird alert even made it in the birding-centric Hollywood movie, The Big Year.

Email changed everything for birding hotlines. With the advent of the listserv, or email message board, call-ins to the Voice of Audubon began to decrease.

Listservs went out of vogue when eBird emerged on the scene, revolutionizing how birders reported their observations. Still, some preferred listservs for the opportunity to discuss sightings in addition to reporting them, for the way listserv conversations build community, and for the ease of reporting a sighting in text rather than via online form. These needs have also come to be addressed by Facebook groups for bird sightings, adding another medium vying for birders’ time and information.

Standing the Test of Time

Through it all, the Voice of Audubon has held firm as a resource for birders, even as it’s call-ins have declined since the heyday of the 1960s and 70s.

Continuing to publish the VoA serves a dual purpose. Firstly, it informs birders who don’t have access to a computer or who prefer the hotline format. Perhaps more importantly, its existence and regular publication in newspapers serves to raise the public profile of birdwatching among the general public.

Do you ever call the Voice of Audubon (781-259-8805), read it in the Sunday Globe, or check out the sightings on our website? Let us know in the comments!

Do Vagrant Birds Indicate a Changing Climate?

It’s been an incredible past few weeks for rare birds in Massachusetts. First, a Purple Gallinule showed up in Milton. Then a White-faced Ibis arrived in Sterling, and a Tropical Kingbird shocked birders in Belmont—the first ever to be seen in Middlesex County. Finally, the first Pacific-Slope Flycatcher seen anywhere in the state was spotted in Hadley, and a Western Kingbird and Rufous Hummingbird rounded out the glut of unusual visitors.

More than 2,000 miles from home, this boldly-colored Tropical Kingbird in Belmont made birding headlines.

It’s tempting to think that these out-of-range birds (or “vagrants”) are the result of climate change. Although climate change certainly affects species’ normal ranges, and may make vagrancy more common and extreme, it’s a reach to say that these “lost” birds themselves indicate any larger trends.

Instead, these birds are just as likely examples of species that only show in Massachusetts every several hundred years. This phenomenon of once-in-a-lifetime birds has plenty of precedent. Consider, for example, the first time a Masked Duck was seen in Massachusetts was in 1889—and the species hasn’t been reported in New England since. Similarly, the first and only record of a Brewer’s Sparrow was in 1873, and the first and only record of a White-tailed Kite was in 1910.

Vagrants: Unpredictable in Predictable Ways

As fall migration draws to a close, there’s almost always a spike in vagrant birds in Massachusetts. Birds from the interior southwest of the US ride winds blowing northeast, often making it as far as the coast.

Many bird populations contain a few individuals prone to wandering. In some cases, wanderers are biologically hard-wired to migrate differently than others of their species, and in other cases, the cause is unknown. These outliers aren’t unique to migratory species; even flightless penguins have been documented walking into the icy mountains of Antarctica, far from any food source.

Most vagrants either perish or (less often) make it back to their home ranges. Even if the vast majority of these birds don’t manage to reproduce on terra incognita, some scientists theorize that having a few exploratory or mis-oriented individuals gives the species an evolutionary advantage. This may allow a population to very occasionally colonize new, faraway areas that turn out to be hospitable, serving as a bulwark against sudden cataclysmic change across its entire normal range.

Climate Affects Vagrants, But Vagrants Aren’t Necessarily Climate Indicators

Fall isn’t the only time when wind patterns regularly bring Massachusetts a handful of unusual birds. Southern birds that overshoot their breeding grounds in spring are mostly the result of wind patterns that blow them far over the Atlantic, where they continue north until making landfall in New England. Even more noticeable are the hurricanes that have brought tropical seabirds like Sooty Terns and Red-billed Tropicbirds inland into Massachusetts.

As rising global temperatures create stronger storms and shift continental wind currents, it’s reasonable to think that new patterns in bird vagrancy will emerge. This doesn’t mean, however, that recent “firsts” (such as last month’s Pacific-slope Flycatcher or Tropical Kingbird) are indicators of climate change– especially with only 200 years of records and a long list of vagrants that showed up in the 18th century and never again.

Demonstrating an increase in vagrant birds (or changes in where they show up) is a tricky proposition, in part because there’s no good way to adjust for how many people are looking. Not only has the number of birders increased dramatically since the 19th century, but birders’ knowledge of how to predict vagrants has improved—and their interest in finding them has intensified. This complicates studying patterns in bird vagrancy, let alone linking them to long-term climate trends.

Fall is Social Season for Blue Jays

Fall holidays mean family gatherings – for people and for Blue Jays. Much like people, these highly social birds are more active in the fall, when the harvest is good and families are reuniting. This pattern is borne out by data on eBird, when observers’ Autumn checklists show a spike in sightings. Here are a few explanations for jays’ noisy behavior right now. 

Image: David Young

Predators on the move mean agitated birds 

When there is a predator nearby, many birds exhibit mobbing behavior to warn others of the threat. This means loud calling and erratic flight patterns. During migration, higher numbers of hawks, owls, and falcons may excite young jays and cause them to vocalize more frequently.  

Blue Jays have also been known to imitate hawk calls. Some researchers think this is a signal to their flock of a potential threat nearby. Others believe Blue Jays are cleverly trying to scare other birds away from their food source. Ross D. James, in a 2002 edition of Ontario Birds, theorizes that young birds learn raptor calls during periods of high stress and excitement and therefore will reproduce them under those same conditions.  

Acorns are plentiful  

Image: Peter Flood 

Every two to five years, Oak trees drop their acorns in much higher abundance than usual. These periods of higher acorn production are called “mast years” and greater Boston residents have taken notice. Fortunately for Blue Jays, who eat mostly seeds, this means lots and lots of food. They flock to areas with high densities of Oak trees, like many Massachusetts forests, and call out to their kin that they’ve hit the jackpot. 

Winter flocks are recruiting 

Blue Jays are winter residents in Massachusetts. Some individuals do migrate, but little is known about how or why they decide to do so. Families group together in large flocks starting in the fall. These flocks are constantly communicating potential threats and food sources since fledglings are still learning the ropes.  

One study of Blue Jays at Mass Audubon’s Wachusett Meadow Wildlife Sanctuary observed wintering jay groups of 14-49 individuals. These birds tended to stay in the same groups throughout the winter and in subsequent years.  

Image: Raina Aiello 

Have you noticed more Blue Jay activity lately? Let us know in the comments! 

Bird-a-thon and Southern Overshoots

Bird-a-thon, Mass Audubon’s annual competitive birding fundraiser, is fast approaching on May 10-11! Spring migration is heating up right on time for the big day– with a few surprises in the mix.

This year’s migration has been marked by an unusual number of southern species overshooting their breeding grounds and ending up in Massachusetts. These “southern overshoots” ride the winds to our state and only stay for a few days before returning to their normal ranges in the mid-Atlantic and southeast, but it’s fun to see them while they’re here!

The Slingshot Effect

Southern overshoots require more than just south winds over Massachusetts. Birds aiming for southerly climes only get a boost into our state when winds line up just right across the eastern seaboard in what’s called the “slingshot effect.”

This pattern starts with strong wind blowing birds offshore over Florida, the Gulf, or the Southeastern US. These birds normally return to land unless they meet a strong south-to-north air current over the ocean, which “slingshots” them northward until they meet the coast of New England. A heavy west wind over the entire mid-Atlantic region can also prevent them from returning to shore until they make landfall in our region.

Here are just a few of the species that rode “slingshot winds” up to Massachusetts in the past month, with maps comparing sightings from April 2018 with April 2019:

Summer Tanagers

Summer Tangers are birds of humid thickets in the southeastern US. Last April, none were reported in mainland Massachusetts. This year, two were seen in Plymouth, one on Plum Island, and a handful as far north as Maine!

Summer Tanager sightings – April 2018
Summer Tanager Sightings – April 2019

Hooded Warblers

Another bird prone to the “slingshot effect,” Hooded Warbler been unusually numerous this year, including late into the month. Here’s the same comparison between this and last April:

Hooded Warbler sightings – April 2018
Hooded Warbler sightings – April 2019

Blue Grosbeaks

Similarly, last April produced just two reports of Blue Grosbeak, a grassland bird of warmer climes. This April, there were no less than 12!

Blue Grosbeak sightings- April 2018
Blue Grosbeak sightings – April 2019

Sign up for Bird-A-Thon and Find Southern Wanderers!

Bird-a-thon is coming up on May 10t-11. Make sure to join a Bird-a-thon team if you haven’t yet! Then, find out which award you’re competing for, plan your strategy, and tell your friends who you’re raising money for!

If the current forecast for Bird-a-thon weekend holds, some overshoot species will no doubt be a key piece of the winning checklists. Southern overshoots get most attention from in-the-know birders in late April, mostly because it’s so striking to see them arrive even before our more common spring migrants show up. But conditions for overshoots can persist into early May, when southern birds show up at coastal thickets and migrant traps like Mass Audubon’s Marblehead Neck Wildlife Sanctuary and Mount Auburn Cemetery in Cambridge (psst– that’s a hint!)

If you’re joining us for Bird-a-thon, good luck, and may the best team win!

The Cardinal Chimaera: half male plumage, half female

Chimaera Northern Cardinal in Erie, PA (Photo by Shirley Caldwell)

Sometimes Nature offers up anomalies that seemingly defy credibility. Such was the case when a striking Northern Cardinal showed up recently at a backyard bird feeder in Erie, Pennsylvania. In appearance the cardinal appeared to have the typical red plumage of a male on its right side, and the light buffy-brown plumage of a female on the left side. So what’s the deal, you may ask?

This remarkable cardinal isn’t quite as unusual as you might suppose. It is actually a classic example of a chimaera—also known as a bilateral gynandromorph. So what does this mean in everyday-speak? A little review of Biology 101 reminds us that in humans, males have one copy of each sex chromosome (i.e. X and Y) while females have two copies of the X sex chromosome. In birds, this scheme is a little different in that in birds the sex chromosomes are referred to as Z and W, and it’s females that carry a single copy of the ZW chromosome, while males on the other hand have two of the ZZ chromosomes. Accordingly the cell nuclei of avian reproductive cells normally would possess only Z-carrying sperm cells in males, or Z or W-carrying egg cells in females.

Very rarely however, individuals occur where a female egg cell develops two nuclei — one with a Z sex chromosome and one with a W sex chromosome—and then gets fertilized twice by two Z-carrying male sperm cells. Clearly the odds of this happening are very low, but when it occurs, literally half of the double-fertilized product offspring will exhibit one set of gender characteristics while the other half will exhibit characteristics of the other gender. In the present instance, the right half of the Pennsylvania cardinal is exhibiting male features and the left side the features of a female. An ultramicroscopic examination of cells from the male half of this cardinal would reveal that it has a ZZ chromosome makeup, while cells from the female half would have a ZW makeup.

As if the circumstances described above are not improbable enough, the fact that the female (or left half) of the Pennsylvania cardinal has to be carrying both Z and W sex chromosomes, it’s actually possible that the bird could become fertilized since in birds, only the left ovary is functional! And the most exciting news of all is that the Erie cardinal is currently keeping company with a normal male Northern Cardinal, and local ornithologists are carefully tracking the chimera to see if it successfully breeds and lays eggs. So stay tuned for what could prove to be another chapter of this remarkable circumstance.

In conclusion it should be pointed out that such genetic reproductive anomalies may not actually be as infrequent as they might seem, since unless a species is strongly sexually dimorphic (i.e., males and females with highly different-looking plumages), bilateral gynandromorphism may not be as readily detectable as it is in cardinals. As an example, check out the “half-sider” images of a Rose-breasted Grosbeak that briefly attended a Newbury, MA feeder in 2015. For a full account of this individual, see Bird Observer (Vol. 43, No. 5, 2015).  Additionally, bilateral gynandromorphism is not uncommon in certain insects, fish, and even rarely in mammals. So if nothing else, not only have you possibly learned some new scrabble words, you may also now know to be particularly careful when you think you’re seeing double!

“Half-sider” Rose-breasted Grosbeak spotted in Newbury, MA in 2015 (Photo by Peter Brown)

Note: This post has been updated to remove an anachronism.

The Greatest Black Hawk: An epic journey recounted

Great Black Hawk by John Harrison

Black hawks are hefty, Buteo-like hawks not too distantly related to the widespread and familiar Red-tailed Hawk (Buteo jamaicensis). There are several species, but most common are the Common Black Hawk (Buteogallus anthracinus) that sparingly nests in the extreme southern portions of the southwestern U.S. south to northern South America, and the Great Black Hawk (Buteogallus urubitinga) that primarily breeds from coastal Mexico south through tropical South America. Both species feed on a variety of creatures including reptiles, amphibians, crayfish, crabs, small mammals, and occasionally even birds.  Both black hawks are relatively sedentary and neither species is a long-distance migrant.

With this information in mind, it understandably came as a mind-blowing surprise to several ecstatic birders who saw and definitively photographed for 20 minutes a juvenile Great Black Hawk on South Padre Island on the coast of Texas, April 24, 2018.  But this is only the beginning of a saga! 

Fast forward to August 6 in Biddeford, ME, where the same individual Great Black Hawk was again definitively photographed and the images were matched exactly to the April sighting in Texas.  The hawk lingered in Biddeford until August 9 before once again disappearing, this time until October 29, when it showed up in Portland, ME! Only this time the elusive tropical raptor only stayed under cover until November 28 when it appeared in a different part of the city only two miles away.

Virtually as I write, this itinerant tropical raptor is still present in the vicinity of Deering Oaks Park, just west of downtown Portland where it has become headline news and is happily feeding on the plethora of gray squirrels inhabiting the urban park.  What will be its ultimate fate when the snow flies and the inevitable cold becomes extreme may never be known….but for now, this has to be the Greatest Black Hawk of them all!

A Birder’s First Christmas Bird Count

This is a guest post by Nick Tepper. A recent graduate from the University of Vermont, Nick is an up-and-coming expert on New England birds, a lifelong naturalist, and is currently fulfilling an AmeriCorps service year with Mass Audubon.

It was 5:30am on a frigid causeway in the middle of Lake Champlain– technically Colchester, VT, but we may as well have been in the Bering Sea given the arctic wind and cold. I remember stepping out of the car at our first site and walking the first steps of a two-mile icy bike path into the freshwater ocean. This was the inauspicious start to my first-ever Christmas Bird Count (CBC), in the winter of 2017. We could barely see, perhaps because the sun had not yet risen, or perhaps because of the 20mph winds that froze our eyelids shut. I spent the next hour or so shivering and trying to figure out what we were doing out there!  Why torture ourselves? Had we no self-respect?

Finally, the sun rose over the trees, and somehow in the –12-degree weather, it was warm. Looking towards the sunrise, we saw birds begin to appear in the dawn. A Snowy Owl was the first species we saw, glowing orange in the early light. What a moment to behold… its yellow eyes opening for seconds at a time to scan the lake for ducks, just as we did with our binoculars. That bird kept us warm all day. We ended up tallying 48 species, and I learned more about birding than I had in all my younger years memorizing plumage patterns, molts, and call notes.

A distant Snowy Owl perched on a block of ice in a watery, frozen marsh. Photo by William Freedberg.

Birding as defined by my first CBC was not a hobby, a job, or a passion— it was a mindset. More importantly, it is a mindset that people could share. If you participate in a CBC, you will inevitably make acquaintances, connections, and very likely some lifelong friends. For me, the best part of the CBC is that you do not need to be a seasoned birder to participate, you need only have an interest in birds and a pair of binoculars.

CBCs, Formerly Known As Christmas Bird Hunts

The Christmas Bird Count, now a grand tradition understood as an all-hands-on-deck census, was borne out of a more grisly 19th-century rite. CBCs were developed by conservation-minded ornithologists as replacements for a tradition known as the Christmas “Side Hunt.” Hunters would celebrate the season by taking “sides” after Christmas Day and filling the sky with bullets, with the goal of (quite literally) stacking up as many species as possible.

During the holiday season of 1900, noted ornithologist Frank M. Chapman piloted the idea for a Christmas Bird Census instead of a competitive hunt. On Christmas Day 1900, Chapman and 26 other counters pioneered 25 counts, counting 90 species. The count has since grown. Last year, 76,987 counters completed 2,585 counts internationally, tallying a total of 2,673 species! Even so, the CBC can always use more counters, and the birding community would love to have you along for the jolliest day of the year. 

Join Your Local Bird Count!

While some CBCs have already taken place, there are plenty more in Massachusetts before the year is up. Try getting in on one of the following:

  • The Concord CBC will take place on Sunday, December 30, and includes the towns of Concord,Lincoln, Acton, Maynard, Sudbury, and others.
  •  The Marshfield CBC is scheduled for Sunday, December 30 on the South Shore, and includes Marshfield, Duxbury, Hanover, and Pembroke.
  • The Newburyport CBC will take place next weekend on Sunday, December 23, and includes an abundance of saltmarsh habitats including Salisbury State Reservation, the famed Plum Island, and several towns on the North Shore.

Evening Grosbeaks Used To Be Common In MA. This year, They’re Back.

Just as ornithologists predicted, 2018 is shaping up to be a banner winter for a number of nomadic finches in the Northeast, especially Evening Grosbeaks. Having steadily declined as winter visitors since the 1970s, these predictably unpredictable birds are a welcome sight this year.

Evening Grosbeak (Creative Commons)

Irruption Years: Boom And Bust

Evening Grosbeaks, like several species of “winter finch”, rely on conifer seeds and berries whose yield in the wild (or “crop”) varies intensely from year to year. When cone and berry crops in certain areas of the boreal forest are strong, winter finches stay close to their breeding areas year-round. When cone and berry crops fail, winter finches become nomadic, sometimes moving hundreds of miles to the south and to lower elevations.

Even within the season, these birds move around a ton. After an historic number of Evening Grosbeak sightings this mid-November, things seem to have quieted down a bit. EBird records suggest that as many birds may have moved on from or even “overshot” Massachusetts and landed deeper into the mid-Atlantic.  This is unlikely to last though—new pulses of irruptive species will continue into the winter and there is still plenty of finch forage left in the trees.

Shifting Distributions

Misconceptions abound regarding Evening Grosbeaks’ status in Massachusetts, in part because this species’ distribution is in almost constant flux.

The last Breeding Bird Atlas showed these grosbeaks breeding in small but growing numbers in the western highlands of Massachusetts, despite a precipitous decline in winter observations statewide. Climate change is shifting the general range of this species northwards, and the prognosis for breeding grosbeaks in Massachusetts–which rely on climate-sensitive and declining conifer species– is grim. Indeed, eBird data suggest they may have already declined since the last atlas.

Birders who were around in the 1960s and 70s often fondly remember the times when Evening Grosbeaks were abundant every couple of winters. It’s a popular misconception that this species was naturally abundant in Massachusetts, and that climate change alone is responsible for their shifting status.

In fact, breeding Evening Grosbeaks were historically restricted to northwestern North America. Their population slowly advanced south and east during the latter half of the 19th century until a significant irruption brought them into the northeast in 1890. The 1890 irruption carried them as far east as Revere Beach, and in subsequent winters, the birds returned in larger and larger numbers. Nearly 14,000 Evening Grosbeaks were recorded in the 1972 Christmas Bird Count, but in the 1990s and 2000s, their winter range shifted away from Massachusetts dramatically– despite a modest increase in local breeders.

This Year’s Conditions

Winter finch irruptions do not only reflect a snapshot of food availability in the current year, but are affected by longer-term trends. For example, 2017 was an excellent year for cone crops in Manitoba, Ontario and Quebec, leading to increased reproductive success for seed-eating birds. This year, winter finch numbers are high as a result– in a year when food happens to be scarce.

This makes it a particularly good year to put out black-oil sunflower seeds, Evening Grosbeaks’ birdseed-of-choice. While many Evening Grosbeaks have been reported eating crabapples and ornamental tree fruits this winter, they’ve also been showing up in strong numbers at feeders.

Check out Your Great Outdoors for more information on this year’s winter finch irruption!