Author Archives: 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.

Loons Return to Plymouth County after a Century-Long Absence

Posted on July 24, 2020 by William Freedberg

Fast on the heels of Bald Eagles’ exciting return to Cape Cod, another iconic species of the north has recolonized Southeastern Massachusetts after more than a hundred years’ hiatus. This summer, Common Loons are raising chicks in Plymouth County for the first time since at least 1872.

It started with an oil spill

A pair of Common Loons in Maine, the birthplace of most of Massachusetts’ reintroduced loons. Photo by Will Freedberg.

Loons used to be common in some of the deep, clear lakes of Plymouth County until the 19^th century, when sport hunting and state-sponsored extermination programs removed them from the state entirely. While loons that breed in New Hampshire and Maine spend winters off the Massachusetts coast, it wasn’t until 1975 that they started nesting here again. In fact, Massachusetts is the only state where loons have returned of their own volition, and they now number over 100 birds—but only in the north-central and western parts of the state.

Strong, proactive environmental laws are enabling loons’ renewal to this part of their original range. The male of the Plymouth County pair arrived as part of a reintroduction program, funded by a legal settlement over a Buzzard’s Bay oil spill.

In 2003, the population of overwintering loons in Buzzards Bay took a hit when an oil barge spilled 100,000 gallons of oil into the water after striking a rock. The spill killed over 1,000 marine birds (the total loss, accounting for those birds’ future contributions to their populations, is closer to 20,000 birds).

Under the Oil Pollution Act of 1990, the barge company had to pay to clean up its mess. (At the time, the Migratory Bird Treaty Act also required that companies pay to restore any birds they accidentally killed, whether or not an oil spill was involved). Some of the funds went towards habitat protection, lead fishing tackle cleanups, and artificial nest sites in areas with existing populations. But there’s no easy way to quickly replace 530 Common Loons, especially when it’s not clear which breeding areas the dead birds came from.

So, the remainder of the funds went towards facilitating loons’ return to places they had historically occupied by translocating “excess” birds from upstate New York and Maine. When loons have two chicks, one often outcompetes the other, which is less likely to survive—making the second chick a great candidate for captive rearing.

Giving loons a head start

Local loon reintroduction efforts formally began in 2015, when the Biodiversity Research Institute began raising loon chicks in captivity in partnership with state wildlife agencies. For the next few years, they managed to release around eight young-adult loons annually into unoccupied, good-quality habitat in Massachusetts.

The project’s success would only become clear a few years later. Young loons don’t breed until they reach several years of age, spending at least the first three years of their life at sea. The marine areas they use as juveniles continue to be their wintering grounds as lake-breeding adults.

While one of the (now fully-grown) male loons has returned to the Plymouth County lake where it was raised for the past couple of years, it was joined by a fully wild female in the spring of 2020. Their chick— the first of what will hopefully be many to come out of the translocation effort—was spotted a few weeks later.

Strong conservation laws yield results

In this case, loons’ reintroduction into southeastern Massachusetts was part of a larger vision for restoring public resources—from fisheries, to swimming beaches, to migratory birds—after they were accidentally damaged by a private company.

But were the damage to bird populations not caused by an oil spill or other pollution that affected people’s health, only the MBTA could have been used as a legal tool to require that a company make amends. Now, that framework is gone—and the current administration’s decision may soon become difficult to overturn.

Birders have already observed several other loons from the reintroduction project at different sites across eastern Massachusetts. If you see a loon with a leg band, or on fresh water inside of route 495, let us know in the comments!

Looking for Love in All the Wrong Places: The Woodcocks of Alewife Reservation

Posted on March 27, 2020 by William Freedberg

American Woodcocks appear to be thriving at the Alewife Reservation in Cambridge, an urban wild sandwiched between office complexes and a subway garage. Despite the myriad dangers of city life, up to a dozen woodcocks perform their aerial mating displays over Alewife every March.

Resilience against the odds

Alewife is awash in threats to these hapless birds. Peregrine Falcons occasionally snag woodcocks in midair as they hunt along the clifflike walls of a brutalist-era parking garage. The expansive glass façade of the recently-expanded office park looms over the adjacent greenspace, causing fatal window collisions. Feral cats prowl around the urban wetland’s thickets. Heavy metals and pollutants from long ago still linger in the soil.

At Alewife, small patches of woodlands, wetlands, and fields persist amid urban infrastructure and new development.

And yet, at least a handful of woodcocks return here every year. In early spring, they give their explosive, nasal calls at dusk, leap into the sky, and twist and turn in midair to attract a mate. Once paired off, they nest and raise young in nearby woodlands.

Is it a trap?

It’s worth considering that this urban wild might be what’s known as an “population sink,” or “ecological trap.”

An ecological trap is any low-quality habitat where more birds die than can successfully reproduce, but which attracts birds even when there’s safer places for them nearby. Traps can appear to have a stable population of birds, when in fact most of those birds die before being replaced as more birds are lured in from safe areas.

A population sink, on the other hand, doesn’t necessarily attract birds more than areas with suitable habitat. Rather, birds end up there as “overflow,” when better territories are fully occupied or made inaccessible. Sinks don’t cause as steep declines, but do put a cap on the birds that can successfully reproduce in an area.

So, it’s entirely possible that Alewife isn’t doing the woodcock population any favors. No woodcock nests have been found in the area, but that doesn’t necessarily mean they’re failing to reproduce.

Brushy fields are all you need

Whether or not Alewife is a net plus or minus for its resident woodcocks, data from the rest of the country show that habitat availability is the main factor limiting woodcock abundance.

The strange, lumpy, long-billed form of an American Woodcock (Scolopax minor). Photo: Will Freedberg

Woodcocks love fields with low, woody brush, and adjacent mature forest. They display in springtime over open, grassy areas, but need some cover—ideally patches of shrubs or grass 2’-5’ high—for shelter. They use forest to forage during the rest of the year, especially when they’re raising young.

Without disturbance, either by fire, mowing, or agriculture, brushy fields revert to forest in a couple of decades. This is the story of woodcock habitat across Massachusetts: most ex-farmland has reverted to forest. Remaining fields are farmed more intensively, leaving less and less brushy patches and edge habitat, and fallow fields are becoming rarer.

Mass Audubon’s Foresters for the Birds program is emphasizing the value of young forest and shrubland habitat for birds. By educating foresters and landowners on bird-friendly forestry practices, we’re trying to create more habitat for woodcocks and other young forest specialists.

Keynote at This Sunday’s Birders Meeting: Peter Marra

Posted on March 6, 2020 by William Freedberg

Do you remember the paper on bird declines that made global headlines last fall? Its lead author, Pete Marra, will be speaking on the science behind bird migration at this Sunday’s Birder’s Meeting.

Marra’s studies have helped guide bird conservation priorities for the past 20 years, in part through his work at the Smithsonian Institution and Georgetown University.

This Sunday, we’ll get to hear him discuss new discoveries on how, why, and where birds make long-distance journeys—and why it may not be too late to save some of North America’s most imperiled migrants.

Other speakers will follow the theme of bird migration:

Mariamar Gutierrez will take us through the ways in which new technologies can help us track and understand migrant birds’ movements.
Sean Williams, ornithology professor and one of Massachusetts’ top birders, will discuss the best hotspots for seeing big numbers of Spring migrants.
Speakers on Chimney Swifts (Margaret Rubgea– UConn), shearwaters (Kevin Powers–FWS), window strikes (Will Freedberg– Mass Audubon) and more!

Of course, there will be a number of other draws in addition to speakers. We’ll have a vendors area staffed by nature tour agencies, booksellers, and local bird-related companies. A number of raffle items will include field guides, bird feeders, and other birding goodies. Most importantly, there’s the chance to meet new community members, catch up with old friends, and stay up to date on news in the Massachusetts birding world.

Attend the Event

Whether you come out to learn, socialize, or both, we hope you’ll join us this year!

The 2020 Birders Meeting will take place on Sunday, March 8 from 8 am-4:30 pm, at College of the Holy Cross in Worcester.

Get your ticket >

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

Posted on November 12, 2019 by William Freedberg

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, 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?

Posted on November 6, 2019 by William Freedberg

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 18^th 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 19^th 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.

29% of America’s Birds Are Gone. What Are We Doing About It?

Posted on September 24, 2019 by William Freedberg

“Species extinctions have defined the global biodiversity crisis, but extinction begins with loss in abundance of individuals” —Rosenberg et al., Decline of the North American Avifauna (2019)

So begins the first comprehensive review of bird population trends since the mid-20th century. Summaries of the study are available via the New York Times and NPR.

The results were unequivocal: 76% of all bird species in the US are declining, some precipitously. Compiling on-the ground data from Breeding Bird Atlases revealed that the total number of birds in the US has fallen by 29% since 1970. Some groups fared worse than other over the five decades in question: shorebirds were down 37%, warblers were down by 33%, and aerial insectivores were down by 32%. And the total volume of birds in the sky, as detected by the national weather radar, was down 14% in the last ten years alone.

Rusty Blackbirds, an inconspicuous, clear-eyed relative of the more common Red-winged, underwent a population crash of over 93% over the past several decades. They are now rare enough that monitoring them is difficult.

This is bad news. Really bad news. But it’s possible to fight, and it’s even reversible. Scientists and conservation professionals have time-tested and proven strategies for stemming the tide of ecological decline, and the only obstacles are funding, public interest, and political will.

Mass Audubon continues to take a multi-pronged, species-specific approach to mitigate the damage in our state. Here are a few of the solutions we’ve already mobilized:

Habitat protection

Birds simply can’t exist without bird habitat. We protect 36,000 acres of bird habitat in Massachusetts through direct ownership, and another 6,000 through “conservation restrictions” and other legal protections against development.

We’ve recorded 149 species of bird breeding & raising their young on our wildlife sanctuaries– over two thirds of the total species in the state.

Landowner Partnerships

Where we can’t protect land through direct purchase, we find ways to ensure that it’s being used in bird-friendly ways. Many grassland species have healthy populations on agricultural land, and agricultural practices can make or break their prospects for survival. The same goes for forest birds living on land actively managed for timber; birds and forestry can coexist where sustainable practices are applied.

Mass Audubon encourages bird-friendly agriculture through projects like the Bobolink Project, incentivizing landowners to delay mowing hayfields until after Bobolinks and other grassland birds have completed nesting. The project compensates landowners directly for any profits lost due to delayed mowing, and the compensation fund is 100% donor-supported. In 2018, we saved more than 1,000 Bobolink fledglings from going under the mower.

Similarly, our Foresters for the Birds program pushes a bird-friendly approach to forestry in Massachusetts. One of our sanctuaries even acts as a demonstration site for how sustainable forestry and bird habitat go hand in hand.

Direct Habitat Management

Mass Audubon is directly responsible for managing between 40-50% of Piping Plovers (a federally Endangered species) in Massachusetts, a state with 1/3 of the Atlantic Coast population. We also are responsible for 20% of the state’s American Oystercatchers, and 40% of its Least Terns.

Since 1986, Piping Plovers have rebounded from 135 pairs to 680 pairs.

While the Cornell study showed shorebirds declining on a continental scale, conservationists in Massachusetts have known that shorebirds were in trouble since the middle of the last century. That’s why Mass Audubon developed our Coastal Waterbird Program to protect shorebirds through management, conservation, policy development, and education.

Science-based Advocacy

In the past year alone, Mass Audubon petitioned for three species to receive special legal protections from the state: Eastern Meadowlarks, Saltmarsh Sparrows, and American Kestrels. These petitions were based on our own monitoring of these species’ populations, which are in particular trouble and require intervention, as well as growing consensus among ornithologists.

We also speak up when legal frameworks for protecting birds are under attack. The rollback of the Migratory Bird Treaty Act last year was a major setback for bird conservation, and we spoke up.

Fight the decline with your donation today >

Field Notes: Southern Breeding Birds Are Moving North

Posted on September 16, 2019 by William Freedberg

“Whe-peet!” Hearing the explosive, snappy squeak of an Acadian Flycatcher at a Mass Audubon sanctuary would have been a huge surprise, were it not for the species’ ongoing shift northward into Massachusetts. Stumbling on this denizen of the American South used to be a downright rare occurrence here, but the northern edge of its summer range has advanced in fits and starts since the early 2000s.

When this particular bird was observed defending a territory at a sanctuary in Central Mass this summer, it was the first time it had been recorded as a likely breeder at a Mass Audubon property. Yet breaking the news in the Bird Conservation Department’s offices elicited mild enthusiasm and a hint of fatalism, with reactions ranging from “Cool!” to, “yeah, they’re comin’.”

Along with a few dozen other species, it seems this once-scarce visitor is on track to become a regular summer resident in a growing part of the state.

As Climate Changes, So Do Bird Ranges

Data from Mass Audubon’s first and second Breeding Bird Atlases showed an increase in breeding records of Acadian Flycatcher between 1974–2011.

Acadian Flycatchers are a naturally inconspicuous species, but other birds have made more dramatic entrances into Massachusetts. Red-bellied Woodpeckers are a loud, gaudy species of wet southeastern forests that have become downright common throughout southern New England. Northern Cardinals delighted birders in the middle of the 20^th century as their brilliant reds and muted oranges became common sights in suburban yards and city parks.

*A Red-bellied Woodpecker at a backyard feeder—in the dead of winter! Photo by Christine McCormack.*

All of these range shifts have been thoroughly documented by scientists as well as casual birders. The most comprehensive effort to document these changes is coordinated by the National Ecological Observatory Network (NEON). Mass Audubon is NEON’s partner for bird data in New England, and every summer, our staff contribute bird censuses to NEON from across the region.

NEON treats birds as one piece of a vast puzzle: by studying how long-term ecological trends line up with each other, the project aims to parse out the causes and consequences of environmental change. Read more about our work with NEON in this blog post!

The Role Of Ecological Monitoring

Range shifts represent more than a curiosity to ornithologists. Rather, they are part of larger ecological disruptions caused by a warming climate and other human-caused factors like agricultural intensification, urbanization, and invasive species.

While a few species adapt to these changes and even benefit from them, they do spell trouble in the grand scheme of things. Niches go unfilled as some species’ ranges shift away from habitats they were once well-adapted to, leaving their home ecosystems in flux. Other species’ ranges are limited by physical factors like elevation, or by the distributions of their competitors or their food source. Birds with finely-tuned ecological roles struggle to adapt to changing conditions, most bird species’ populations decline.

This makes keeping tabs on bird populations critical.

Conservationists first establish which species are declining or adapting (and why, and how) in order to target habitats to create or manage and prioritize species for legal protection.

This leads to concrete action, like advocating for the state to list acutely declining species as Endangered, or creating young-forest habitat at wildlife sanctuaries– all pieces of planning for a future with brave new ecological realities.

The Death of a Warbler: A Tragedy in Four Chestnut-sided Parts

Posted on August 9, 2019 by William Freedberg

Prologue

In addition to collecting data on bird-window collisions, Mass Audubon’s Avian Collision Team also generates many good stories that range from hopeful, to tragic, to simply strange. While most of the birds our volunteers found were dead, some were nursed back to health at the Tufts Wildlife Clinic. What follows is an account of one window-struck Chestnut-sided Warbler (Setophaga pensylvanica) that proved to be an emotional roller coaster for our project coordinators.

Part I: The warbler is alive

A dedicated ACT volunteer called up about a handful of window-struck birds outside a building facing the Boston Public Garden. Most were dead, but for a single Chestnut-sided Warbler. It was apparently sitting on the curb, visibly breathing, but injured. The volunteer was a little shaken up. Since they didn’t have a net or tools to safely catch the bird, I advised them to wait to see if the bird could fly off on its own before trying to catch it.

Our volunteers snapped a quick cell phone photo of the injured warbler next to the curb.

Part II: The warbler is dead

A few minutes later, the volunteer called back– sounding even more shaken. The bird had flown away, but just as it lifted off, it was caught in a gust of wind from a passing car and was struck by the fender. From the volunteer’s description, the bird was truly lifeless. The volunteer said they would take the carcass back to their freezer and eventually bring it to the Harvard zoology museum, where we had been depositing specimens for research.

Part III: The warbler is alive, again

“It’s alive!” were the first words out of the volunteer’s mouth on our third phone call within a half-hour. “The bag started moving!”

Stunned birds can truly appear lifeless, and in fact, many birds that hit windows are stunned, concussed, or go into shock before eventually shaking themselves off and flying away. But just because a bird can fly doesn’t mean it’s healthy. A broken clavicle or corocoid bone allows birds to make short flights, but prevents them from gaining altitude, halting their migration and making them an easy meal for predators. Any bird found stunned from a building impact is a good candidate for treatment at a wildlife care center.

The volunteer met Mass Audubon staff at a nearby T station to hand off the bird, which was taken to Tufts Wildlife Clinic.

Part IV: The warbler is dead. Again.

The Tufts clinic graciously provides every animal with a case number, so its finder can call up to check on its condition.

While the bird was initially given an optimistic prognosis, we learned a few days after dropping it off that it had suffered untreatable head trauma. The bird had died.

Epilogue

While healthy bird populations naturally fluctuate enough to practically erase the effect of one birds’ death, there is no harm in trying to save individual lives. Naturally, most volunteers prefer to put in the extra effort involved in helping injured birds than leave them to die from an indirectly human-inflicted injury. It was sad not to be able to save this warbler, but we did successfully release a number of other birds, including Brown Creepers, Song Sparrows, Ovenbirds and Common Yellowthroats.

If you want to help monitor window collisions and ambulate injured birds, join Mass Audubon’s Avian Collision Team for its fall migration via this form!

Join the Avian Collision Team’s Second Season

Posted on August 5, 2019 by William Freedberg

Here’s an easy way for anyone living or working in Boston to help migratory birds: help monitor window collisions!

An Indigo Bunting lies stiffly among litter, hours after striking an office building window in Boston. (Photo: ACT)

Mass Audubon is seeking new volunteers for the fall season of the Avian Collision Team (ACT). ACT is an initiative to collect data on bird–building collisions, and to rescue injured birds.

This spring, the team of birders, conservationists, and other concerned citizens observed 115 birds across 38 species affected by window strikes. This fall, and in coming seasons, we need to keep up the momentum and grow our dataset.

The Problem

Window collisions are an under–appreciated source of bird mortality in the US, causing several hundred million casualties annually.

Birds struggle to distinguish reflections from reality, and often strike glass windows that reflect the sky or nearby greenery. City lights also confuse night-migrating birds, which use the stars to navigate, and which often land near sources of light pollution. Many window strikes occur as birds try to re-orient in the morning, after being drawn in to an unfamiliar concrete jungle.

Project Details

The program runs from August 24–October 28 in downtown Boston. Volunteers need to sign up for 1-4 weekly shifts, Saturday–Tuesday, that can take place between 6-9am. Most shifts last around 30-60 minutes.

Volunteers walk predetermined routes through downtown Boston to photograph or collect deceased specimens, fill out data sheets, and occasionally rescue live birds. We’ll be holding volunteer trainings on August 11, 18, and 22.

Carrying out ACT surveys can be an eye-opening experience, between watching the city as it’s waking up, discovering seemingly out-of-place warblers, buntings, and vireos, and occasionally saving the life of an errant, injured migrant. And once you’ve found your first few birds, a collector’s instinct sometimes kicks in, making the search all the more engaging. It’s like birding with a twist– a sense of urgency, purpose, and sometimes, a touch of sadness.

If this sounds compelling, sign up here!

Avian Collision Team: First Season Updates

Posted on July 18, 2019 by William Freedberg

Since mid-April, a team of Mass Audubon volunteers has combed the streets of downtown Boston in search of migratory birds killed by collisions with windows. Here are some preliminary results of our first season running the Avian Collision Team (ACT).

The first statistic that jumps out is the higher-than-expected number of live, injured birds found by our volunteers. Based on what we heard from New York, Chicago, and Toronto, we had told volunteers it was highly unlikely they’d be able to save any injured birds. This ended up being far from the truth! Here’s one video of a Brown Creeper that was well enough to be released after suffering non-life-threatening head trauma:

The Five “Hardest-hit” Species

Some patterns are also beginning to emerge in the species of birds we’ve been finding. Here’s the full breakdown:

The five most frequently-encountered birds (in bold text above) have something in common: they’re all low-flying migratory species, and they’re relatively common. Certain buildings also seemed to kill a disproportionate number of birds that climb trees vertically, like woodpeckers, nuthatches, Black-and-white Warblers, and Brown Creepers. Other cities have reported similar species profiles with an emphasis on common migratory birds that fly low and weakly.

The Bottom Line

A few dozen people surveying a thin slice of the city for an hour or so per week found 119 window-struck birds of 38 species.

Other cities report that certain seasons have up to four times the number of strikes than others. The wide variability of window strikes makes it difficult, after just one season, to make broad statements about how many birds die from collisions in Boston annually, or establish how Boston shapes up compared to other cities. That said, our numbers fall roughly into the range reported by similarly-sized programs in other cities, like Baltimore, Detroit, and New York.

After accounting for scavengers, industrious building cleaners, and low volunteer detection rates, it’s estimated that only 10-20% of window strikes on a given route are actually recorded. That makes our numbers all the more sobering, especially considering our volunteers covered less than 1/50th of the street area of Boston.

That said, window strikes by themselves may not drive bird declines in Massachusetts. Window strikes are an additional stressor, however, on top of a laundry list of human-caused threats to bird populations. In today’s world of climate change, habitat loss, and invasive species, every bird counts– which is why window strikes are worth understanding.

Cities Are Only Part of the Problem

Outside the study areas in Downtown Boston, our volunteers reported many casualties even without focused searching. Their findings emphasize what other studies already suggest: window strikes are at least as much of an issue at single-family homes and low-rises as they are at tall urban buildings.

The good news is that there are lots of ways to make your home or office windows bird-safe. Here are some tips:

Screens on windows are the cheapest and perhaps simplest option: they break up reflections and also provide a springy barrier that collision-bound birds can bounce off of.

Where screens are impossible, consider buying or building an Acopian Bird Savers (hanging lengths of bird-deterring string). Learn how to build your own here!

Window decals only work when spaced less than 2” apart vertically and 4” apart horizontally, but when used correctly, they’re another great option. Certain kinds are transparent to human eyes, so even narrowly-spaced ones won’t interrupt your view.

Installing UV-reflective patterned glass like Ornilux is extremely effective, and by far the most discrete option– but also the most expensive.

Finally, turning unneeded lights off at night helps conserve energy and avoid drawing birds into strike-prone areas.

(Disclaimer: Mass Audubon has no affiliation with any of the above vendors).