Studying Forest Structure At Elm Hill

Our bird conservation staff spent the past week collecting data at Elm Hill Wildlife Sanctuary, our demonstration site for Foresters for the Birds. Since we’re using this site to show how responsible forest management can enrich bird habitat, we need before-and-after data to compare changes in vegetation and bird diversity.

Birds See Forests For The Trees

The physical structure of a forest directly affects which birds are found there. The amount of vegetation near the forest floor (or “understory”) changes whether or not the forest can host a whole suite species that nest near the ground, like Ovenbirds and Black-throated Blue Warblers. Forests with open midstories (the layer of vegetation between 5–50 feet off the ground) attract flycatching birds like Eastern Wood-Pewees, but dense midstories appeal to Wood Thrushes and Canada Warblers.

The goal of our work at Elm Hill is to demonstrate how every forest species has its own habitat preferences, and how thoughtful land management can create habitat for declining species. Since three quarters of Massachusetts’ forests are in private hands, it’s critical to make these lands as hospitable as possible to wildlife.

Collecting Vegetation Data

A data sheet we use for recording information about trees and forest structure at Elm Hill.

Before we alter any habitat at Elm Hill, we’re recording these factors at sites where we’ve previously done bird surveys:

  • Total woody biomass (i.e., the average size and number of trees in a given area)
  • Tree species makeup (i.e., which trees are there, and how many of each)
  • Canopy density (i.e., the amount of cover provided by leaves in the treetops)
  • Sapling density (i.e., the number of young trees from around 1–6 feet tall)
  • Coarse woody debris (i.e., the number of logs and slash piles on the ground)

We outline a 400-square-meter plot with ropes at every site to make sure we collect data from the same area of land each time. This works pretty well until somebody tangles the ropes:

Jeff tangled the ropes. It definitely was not me.

While measuring trees, logs, and saplings is straightforward, you might wonder how researchers measure canopy density— and the instrument for this is quite cool. A spherical densiometer (pictured below) condenses a wide view of the canopy into a small image (much like a fisheye camera lens) with a grid over it. By estimating the percentage of each grid square occupied by leaves or trunks (and adding them up, and taking readings in each cardinal direction), we have a standardized and simple way of measuring canopy density. This also works as a proxy for determining how much light reaches the forest floor.

A spherical densiometer, used for measuring the amount of leaves in the treetops.

Long-term Goals

After foresters have cleared the woods of invasive species and created a variety of spatial habitat types, we’ll be able to show what changes this brings to Elm Hill’s bird species.

Elm Hill contains mostly 70–90-year-old forest, like much of Massachusetts. We’ll manage parts of the sanctuary for birds that prefer young forest, which are in trouble statewide, and in other part’s we’ll try to mimic old-growth forest conditions, which would take over a century to emerge naturally. Hopefully, we can then use this site as a physical example of how foresters and landowners can improve bird habitat on the properties they manage.

 

 

Cities Need Bird-Friendly Buildings

Between 100 million and 1 billion birds die annually from collisions with windows. Glass windowpanes can reflect nearby trees, shrubs, and sky. Birds’ eyes aren’t able to distinguish clear reflections from the real thing, so they sometimes aim for a reflection and fly smack into a pane of glass.

Earlier this year, Mass Audubon’s advocacy team expressed concern about a plan to install an all-glass façade on a building facing Post Office Square in Boston. An island of green in downtown’s sea of concrete, Post Office Square is a locally important stopover site for migratory birds. A few plantings in the middle of a nearly treeless part of the city attracts a surprising diversity of species, and adding a wall of glass panels across from one side of the park increases the risk of collisions . The well-meaning developer wanted to add a perimeter garden and a green roof to the site, which ironically would increase window strikes by attracting birds to reflections of the greenery.

Luckily, when told about the risk the project posed for birds, this developer was willing to make the site safer. They are in the process of installing glass with non-reflective stripes, which will break up reflections of what’s outside and steer birds away from the windows. Many similar technologies exist to make windows visible obstacles to birds without interfering with peoples’ view—from glass incorporating ultraviolet patterns that only birds can see, to entire panes made of non-reflective material.

Post Office Square, an urban stopover site for migrating birds (Photo by Will Freedberg)

You Can Help!

Skyscrapers account for disproportionate numbers of bird deaths, but the number of single-story buildings in the US make them an equally important front for reducing window strikes. Every homeowner interested in conservation can take steps to make their homes safer for birds:

  1. Keeping window screens on year-round. This is a great option because it provides a visual barrier as well as soft, springy physical barrier to incoming birds.
  2. Purchase and apply a one-way, see-through film to your windows, which both cuts reflections for birds and blocks the view into your home from outside.
  3. Finally, any birdfeeders close to your house (within 15 feet) should be even closer to windows (less than 1.5 feet away). While this sounds weird, birds do slow down before perching, so any window collisions as a bird comes in to land at your feeder is unlikely to injure the bird.

 

 

 

 

 

 

 

References: Daniel Klem, 1990: Collisions Between Birds And Windows: Mortality And Prevention

 

50 Years Of Discovery At Great Gull Island

A Season With The Terns

I first visited Great Gull Island as a volunteer in 1980. I was an undergraduate at Southern Connecticut State College, and had friends who worked on the island. I went out for a weekend, and like many others, I never really left. Sure, I’ve gone off and worked in Georgia, on the Farallones, in Cape May, and for Mass Audubon, but there is something about this place that never leaves you.

This year, the project celebrates its 50th year of full-season tern research. I wanted to go back and indulge in a full summer once again. I arrived on April 22 for an 8-week stint, which meant that for the first time, I saw the birds arrive fresh from their wintering grounds in South America. On a cold and grey April 29 morning, burrowed deep into my winter-weight sleeping bag I heard one tern, then a second calling. I raced outdoors, camera in hand, and got a video of them drifting through the clouds, calling as they came home.

A tern and a bander on Great Gull Island. Photo by Joan Walsh.

A quick check of eBird records showed very few had been reported south of us before they came home. Had they flown over water most of the way? Was the last place they saw South America? Did they fly directly to their island? The details of the transit were important to my science brain, but the shimmering white birds falling from the grey sky, calling for their 20,000 neighbors, was one of the most powerful natural moments I have ever witnessed.

They come back slowly – just a few at first, coming in in the morning, the numbers, and noise, building each day. At first they fly in tight flocks, looking more like a group of migrating Red Knots than terns. They leave at midday to go forage, then return at night and through the early morning. Then, one day you realize they aren’t leaving, and some are even courting, then more, then more.

Their tentative residence is no longer. They are home, and they are fierce.

The Setting

Great Gull Island seems unremarkable at first: 19 acres of sand and rock, formed as so much of our coastline was by the terminal moraine of retreating glaciers 10,000 years ago. The island is tiny— about half a mile long and a quarter mile wide.

The island sits in some of the roughest waters in Long Island Sound, between Plum Island and Fisher’s Island, NY. Each outgoing tide drains Long Island Sound of 2-3 feet of water, and about half of that water comes past Great Gull. A typical tide rushes by at 5 knots; a strong tide moves even faster. The sea is often heaped into 4 foot standing whitecaps, giving the water to the east of Great Gull the title of The Race, and to the west, Plum Gut.

The currents are so strong that sandlance and small herring can’t swim well against them, making them easy prey for lurking striped bass and bluefish. The currents also put baitfish at risk from aerial predators, which is one reason Great Gull Island hosts up 30,000+ Common and Roseate Terns during the summer breeding season.

In profile, the island shows a tall “hill” to the east, a flat meadow in the center flanked by another hill, and a long meadow towards the west. Much of the island is lined with huge granite boulders, similar to those used in jetties along the rest of the coast. In the summer the Island sprouts 20 or more small white-topped towers used as blinds for watching nesting birds. This, coupled with severe signs warning “DO NOT LAND” give it an otherworldly appearance – a mysterious place clinging to the bedrock as tide rush by, and thousands of birds swirl and scream overhead.

The Military History

The two “hills” seen in profile are anything but. They are the remains of a US Army coastal defense project. Great Gull was re-christened Fort Michie when the Army ejected the resident tern colony and began construction of a fort in 1896, which they occupied through World War 2. At one point hundreds of men lived on the island in a self-contained small town, complete with electricity, running water, and a hospital. The remains of the coastal defenses are still in evidence everywhere. Most notable are those cement “hills,” honeycombed with tunnels where armaments were stored.

These tunnels, and 6 gun emplacements, are still standing around the island. And the biggest of them all is the massive gun emplacement that held a 16 inch gun – it actually took a shell that was 16 inches in diameter. Three brick officer’s quarters also remain, and two concrete watch towers are still standing. The rest of the fort was reclaimed by the weather or demolished by 1960.

The Return of Nature

After World War 2, the Army sold the island to the American Museum of Natural History for $1, and for the most part little was done on the island for about 10 years.

In the early 1960s, the island was visited by a group of ornithologists from the American Museum of Natural History. One woman, Helen Hays, saw the island’s potential as a research site, grabbed ahold of her work, and 58 years later is still directing the research on Great Gull Island (GGI). A handful of Common and Roseate Terns had begun to colonize the retired US Army fort, and the visitors, being curious scientists, hatched a plan to return Fort Michie to its former natural glory (and name).

The Research

At GGI, Helen Hays has managed thousands of volunteers to amass one of the longest runs of known-lineage data in the world. It is not hard to trap a bird, read the band, and follow that bird’s lineage back to 1980. This is done by daily nest searches, aided now by GPS locations for all nests. A subset of the adult birds are trapped and banded, and as many Common Tern chicks are banded as possible. Roseate Terns, as federally endangered species, have stricter rules for handling. All nests are marked, but a very limited number of adults and chicks are handled.

Despite the presence of the researchers the colony has flourished. Hundreds of papers have come from the work, and each year more questions are brought to the forefront. Helen has encouraged work by independent researchers, and has mentored thousands of ecologists, despite managing one of the most complex research stations on the eastern seaboard.

Four years ago I began a series of simple observations on Common Tern. We had done them in the past, but what would a repeat show? I select a set of nests, and for two hour intervals record the time of each fish delivery to the young. I identify the fish, and estimate the size. Each year I choose between 10 and 30 nests to watch. Preliminary work with the data showed really impressive changes in the feeding rates for the nestlings. For two years we recorded fairly similar feeding rates – each nest received about 1.1 per hour. But in 2018 that rate tripled to 3.3 fish per hour per nest. These data support the anecdotal observations we had on GGI this year – there were a lot of fish!

Data like these are important for understanding the variability in chick survival, and can act as a surrogate for understanding changes in fish populations. Coupled with the long-term research on annual productivity and survival rates on the island, this helps us to flesh out what is happening in Long Island Sound from year to year, and as the waters warm due to climate change.

 

A team of researchers from Argentina that visits Great Gull every Summer. Photo by Joan Walsh.

1,027 Bobolink Fledglings Saved This Summer

By The Numbers: The 2018 Bobolink Project

We’re tallying up the results of this year’s Bobolink Project, and the numbers look great! The Project protected 932 acres of nesting habitat, up from 512 acres in 2016 (which was the project’s first year at Mass Audubon). Field surveys showed 368 pairs of Bobolinks on participating farmers’ land. Since Bobolinks fledge an average of 2.69 chicks every season, this translates to saving an estimated 1,027 Bobolinks—many of which may return to nest again next year!

It takes just 12 days for nestlings to leave the nest, but another two to three weeks before they can fly well enough to escape the mowers used for haying. Photo by S. Bardella

How it Works

Bobolinks rely on grasslands to breed, and often find that hayfields work just as well. Until the mid-20th century, many hayfields were mowed in late summer, weeks after Bobolink chicks had left the nest. Now, high demand for livestock feed means that farmers are mowing earlier and earlier; early-cut hay is richer in protein and more valuable. Sadly, this means that many Bobolink nestlings end up under the mower.

Every year, Mass Audubon offers farmers compensation for waiting to mow their hayfields until after nesting season. This model has so far proved effective: plenty of farmers would rather not mow over active bird nests, but need their hayfields to produce some source of income. Mass Audubon uses donations to cover these farmers’ losses from delaying mowing, keeping their farms economically viable while protecting grassland birds.

Bobolink © Martha Akey

Photo by Martha Akey

Next Year’s Goals

Even with increased donations, the number of interested farmers is outpacing available funds. This year, we had enough funds to protect two thirds of project applicants’ land. We also had to leave an additional 492 acres of Bobolink habitat on the table. Sadly, this funding gap meant that most fledglings on the unprotected acreage didn’t make it.

While it may not be possible to prevent every single agriculture-related Bobolink death across the region, it is painful to have to turn away farmers who want to partner with us to protect birds.

If you’d like to help us protect even more acres and Bobolinks next year, please donate here!

How Do Pelagic Birds Find Fresh Water At Sea?

The short answer: they don’t.

Seabirds drink ocean water, and excrete the excess salt that would otherwise leave them dehydrated. Specialized glands, located above the beak and just under the eyes, filter salt ions from seabirds’ bloodstream. The glands also draw out just enough water to dissolve salt into a highly concentrated saline solution, which runs out through the bird’s nostrils.

If you’ve ever seen a gull standing on dry land, with fluid dripping down the tip of its beak… that’s because it’s expelling salt!

These glands can atrophy and stop working if not regularly used. Seabirds at zoos and wildlife rehabilitation clinics actually need to be kept in saltwater—if their glands stop pumping, the birds can experience salt poisoning when re-exposed to ocean water.

 

A Sooty Shearwater exhibits a typical “tubenose” beak structure: elongated nostrils through which salt is excreted. Photo © William Freedberg

 

Terrific Tubenoses

Birds in the family Procellariformes (which includes albatrosses, shearwaters, petrels and storm-petrels) excrete salt through one or two tubes that sit atop their beaks, giving the group the informal name of “tubenoses”. A common misconception among birders is that this tube is an organ used uniquely for excreting salt.

In fact, it’s not clear that these birds process salt any more efficiently than any other seabirds, like pelicans or marine ducks. Tubenoses’ beak structure might help them keep saline excretions from blowing into their eyes in high oceanic winds, but that’s probably not its primary function.

Recent evidence suggests that these tubes help channel airborne scents, contributing to tubenoses’ ability to sniff out plankton blooms on the open ocean. There’s also evidence that the nasal tubes of albatrosses contain pressure-sensing nerves, helping these birds find and navigate the rising air currents they use to stay aloft.

 

Seabirds Under Threat

Seabirds’ exquisitely fine-tuned sense of smell serves them poorly in oceans plagued by plastic pollution. It turns out that plastic, especially when covered in marine algae, smells just like the zooplankton seabirds love to eat.

While some seabirds that frequent Massachusetts waters are doing well (like Wilson’s Storm-Petrels and Cory’s Shearwaters) others are in serious trouble. And unlike some declining groups, pelagic birds’ absence flies largely under the radar of most land-bound naturalists. Among myriad dangers, entanglement in fishing gear, climate volatility, and invasive species drive seabird declines.

Help fight these threats by purchasing American-caught seafood—fishery regulations here favor seabirds more than in much of the world— and by reducing plastic waste.

The World’s Funniest Bird Sounds- And How They’re Made

Last month’ post about amazing bird sounds from Massachusetts was so popular, we decided to create a definitive ranking of the funniest bird vocalizations from around the world.

How do birds make so many sounds?

Birds have a vocal organ called a “syrinx” that mammals (and other vertebrates) lack. Different groups of birds have specialized syrinxes that can produce different sounds, but all of them allow for a wide variety of vocalizations.

Humans have a single set of vocal chords that sit in the windpipe, or trachea. Most birds’ syrinxes, on the other hand, are located where their trachea branches in two (towards each lung). This allows some songbirds, like thrushes, to regulate the air exiting each lung individually, creating two distinct notes at once. Other birds, like parrots, have a syrinx in their trachea—but with more moving parts than human vocal chords.

All syrinxes share this complexity. In addition to using membranes that vibrate to produce sound, the syrinx contains a network of muscles to “shape” air as it exits their lungs—sort of like how we use our lips to whistle, but with a few added degrees of complexity.


The contenders:

10. Screaming Piha


This group of Pihas from the Amazon sound… just plain rude.

 

9. Slate-colored Solitaire


Like the Veery in Massachusetts, these members of the thrush family give the forest soundscape an ethereal feel with their clear, echoing whistles. Click on 2:18 for the best part!

 

8. Andean Goose


These aren’t flatulent geese- that’s just their syringeal flutter.

 

7. Willow Ptarmigan


Ptarmigans sound cartoonish, and their clucking can resemble the sound of human speech.

 

6. Great Jacamar


Ambush predators of the rainforest mid-story, Jacamars can sit motionless for hours waiting for their butterfly prey to come within catching distance. Their nasal, drawn-out calls fade out towards the end, sounding almost lazy, and evoking the midday heat of tropical forests.

 

5. Short-tailed Shearwater


Shearwaters and petrels are often silent at sea, but clamorous at their burrows.

 

4. Capuchinbird


These birds are incredibly loud, and their voices can carry for miles. They’re known locally as the “calfbird” for their lowing, cow-like moans.

 

3. Laughing Kookaburra


A classic sound of the Australian bush at dawn, gregarious Kookaburras duet and countersing with each other frequently.

 

2. Imperial Snipe


This combination of cackles and what sounds like a landing spaceship is just about as weird as it gets. But the otherwordly humming and buzzing that accompanies the Snipe’s vocalization is created by air rushing past its wings as it displays– so the snipe only comes in at #2.

 

1. Horned Screamer


Screamers gulp like bitterns, honk like geese, and irritate residents of Amazonian South America with their dawn cacophanies like no other bird.

 


With such a wide range of sounds, it’s no wonder birdsong inspired so many human musicians—from Vivaldi’s 17th century goldfinch themes, to DJ Ben Mirin’s wildlife-inspired EDM.

What do you think about this (deeply subjective) ranking? Can you think of any birds that should have made the cut?

 

 

Two Poems for Bobolinks: Dickinson and Bryant

Mass Audubon’s Arcadia Wildlife Sanctuary: a few miles from where Emily Dickinson was inspired by Bobolinks- which have returned to the property thanks to careful stewardship.

References to Bobolinks abound in poetry from 19th-century New England. Massachusetts authors drew inspiration from local birds for a host of reasons, not least because they saw local species as uniquely American subjects (as opposed to, say, the European Nightingale). Bobolinks and Meadowlarks helped distinguish their work from other English-language poets’, and perhaps more importantly, ground it in a sense of place.

Bobolinks were also particularly an familiar and evocative sight through the 1800s and into the past century. Widespread low-impact agriculture provided habitat for field-loving Bobolinks, which don’t mind living near humans as long as their nests are undisturbed. Conspicuous and bold, Bobolinks became an icon of the countryside, and a cultural touchstone for many.

Emily Dickinson, one of rural Massachusetts most-celebrated poets, took a particular liking to them. Bobolinks recurred as a motif in more than 20 of her works. Dickinson often made the birds into rowdy or joyfully anti-authoritarian figures, as here:

 

Some keep the Sabbath going to Church –
I keep it, staying at Home –
With a Bobolink for a Chorister –
And an Orchard, for a Dome –

Some keep the Sabbath in Surplice –
I, just wear my Wings –
And instead of tolling the Bell, for Church,
Our little Sexton – sings.

God preaches, a noted Clergyman –
And the sermon is never long,
So instead of getting to Heaven, at last –
I’m going, all along.

–Emily Dickinson

 

Loosely interpreted, the poem emphasizes finding joy in nature and in the everyday. Here, the Bobolink is part of Dickinson’s everyday “Heaven” on earth; its song part of her quiet resistance to organized religion. Dickinson had studied religion in a seminary, but perhaps tellingly, dropped out after a year.

Dickinson always ascribes human qualities to the bird to illustrate a point—whether as a “Sexton” (someone who rings the bells of a church) calling her attention to beauty in nature, or in other poems, as a disruptive “Rowdy of the Meadow.”

Other poets, however, grounded poems in Bobolinks’ natural history and biology, although few connected them with complex societal themes as adroitly as Dickinson. William Cullen Bryant, for example, managed to accurately convey key points about Bobolinks’ seasonal behavior (despite leaning pretty heavily on twee personification and cutesy metaphors):

 

Merrily swinging on briar and weed,
Near to the nest of his little dame,
Over the mountain-side or mead,
Robert of Lincoln is telling his name:
Bob-o’-link, bob-o’-link,
Spink, spank, spink;
Snug and safe is that nest of ours,
Hidden among the summer flowers;
Chee, chee, chee.

Robert of Lincoln is gaily drest,
Wearing a bright black wedding-coat;
White are his shoulders, and white his crest;
Hear him call in his merry note:
Bob-o’-link, bob-o’-link,
Spink, spank, spink;
Look what a nice new coat is mine,
Sure there was never a bird so fine.
Chee, chee, chee.

Robert of Lincoln’s Quaker wife,
Pretty and quiet, with plain brown wings,
Passing at home a patient life,
Broods in the grass while her husband sings:
Bob-o’-link, bob-o’-link,
Spink, spank, spink;
Brood, kind creature; you need not fear
Thieves and robbers while I am here.
Chee, chee, chee.

Modest and shy as a nun is she;
One weak chirp is her only note,
Braggart and prince of braggarts is he,
Pouring boasts from his little throat:
Bob-o’-link, bob-o’-link,
Spink, spank, spink;
Never was I afraid of man;
Catch me cowardly knaves, if you can !
Chee, chee, chee.

Six white eggs on a bed of hay,
Flecked with purple, a pretty sight!
There as the mother sits all day,
Robert is singing with all his might:
Bob-o’-link, bob-o’-link,
Spink, spank, spink;
Nice good wife, that never goes out,
Keeping house while I frolic about.
Chee, chee, chee.

Soon as the little ones chip the shell,
Six wide mouths are open for food;
Robert of Lincoln bestirs him well,
Gathering seeds for the hungry brood.
Bob-o’-link, bob-o’-link,
Spink, spank, spink;
This new life is likely to be
Hard for a gay young fellow like me.
Chee, chee, chee.

Robert of Lincoln at length is made
Sober with work, and silent with care;
Off is his holiday garment laid,
Half forgotten that merry air:
Bob-o’-link, bob-o’-link,
Spink, spank, spink;
Nobody knows but my mate and I
Where our nest and our nestlings lie.
Chee, chee, chee.

Summer wanes; the children are grown;
Fun and frolic no more he knows;
Robert of Lincoln’s a humdrum crone;
Off he flies, and we sing as he goes :
“Bob-o’-link, bob-o’-link,
Spink, spank, spink;
When you can pipe that merry old strain,
Robert of Lincoln, come back again.
Chee, chee, chee.

– William Cullen Bryant

 

Bryant’s poem draws a parallel between the Bobolink’s behavioral changes over a breeding season and a human who is burdened with work and worry as they age. But the poem is essentially fanciful, and its goal is mainly to describe these seasonal arcs with flowery language. Still, it’s a rare poem for weaving in a significant amount of natural history.

One could say that Dickinson’s and Bryant’s poems have different goals. Dickinson uses the Bobolink as a device to illustrate the experience of finding joy and religion in nature; she ascribes human qualities to a bird to tell us something about ourselves. Bryant’s poem ascribes human qualities to a bird, but more to illustrate points about the bird itself.

Which poem do you prefer? Do you know of any contemporary poems about Bobolinks—or maybe have written one yourself? Share with us below in the comments!

You can also learn more about (currently-living) Bobolinks and how to protect them at Mass Audubon’s Bobolink Project website.

 

Tips For August Nighthawk-Spotting

Aerobats. Daredevils. Show-offs. The bounding, athletic flight the Common Nighthawk makes for an impressive spectacle in late summer twilight, when groups of these birds swoop to catch insects in midflight.

In the last two weeks of August into early September, these birds power across Massachusetts on hooked, falconlike wings. Nighthawks pause during migration to gather and feed near the edges of open fields, making them easy to observe on their way South.

Two Common Nighthawks streak through the sunset light in Cambridge, MA. Composite image by Will Freedberg.

Nighthawks are totally unrelated to hawks, a group with which they share very little. As members of the nightjar family, nighthawks look similar to the closely-related Whip-poor-will when perched on the ground. In the air, they appear totally unique, agilely swooping and diving in continuous flight.

While springtime brings modest numbers of nighthawks to New England, they show up in much greater numbers on their southbound migration. Nighthawks feed on flying ants, which hatch here en masse in late summer, to fatten up before making the long trip to South America. In spring, when insects are scarce, most nighthawks take a more direct route around Massachusetts to their breeding grounds.

Don’t miss the three-week window for seeing migrating nighthawks this year! Here are some tips for finding them.

 

Find a Field

Just before sunset, nighthawks often emerge around grasslands and big fields. Near Boston, nighthawk hotspots include Millennium Park in West Roxbury, Rock Meadow in Belmont, and Heard Conservation Land in Wayland. In the rest of the state, any open hilltop or good vantage point near a river will do!

 

Follow the Rivers

Nighthawks use river valleys to navigate. While any open field is apt to produce a nighthawk sighting at dusk in late August, rivers running North-South tend to concentrate nighthawks in impressive numbers. In the Connecticut River Valley, this can mean over a thousand birds streaming by over the course of the evening—although such a spectacle doesn’t happen every year.

 

Join a Program

Mass Audubon sanctuaries host nighthawk searches in every part of the state! Here are a few that are coming up:

 

Connecticut River Valley
August 22, 2018

Nighthawks and Chimney Swifts at Arcadia Wildlife Sanctuary

This program will begin with an indoor presentation about each bird before heading out to search the sky for nighthawks and swifts.

 

Western Massachusetts
August 24, 2018

Evening Nighthawk Watch at Canoe Meadows

Search the evening sky for migrating nighthawks at Canoe Meadows. With luck, you’ll be able to observe these beautiful aerial acrobats catching insects on the wing. This event is free.

 

Worcester Area
August 28, 2018:

Migration of the Common Nighthawk in Millbury

Learn about nighthawk adaptations, ecology, and how to look for feeding behavior, while witnessing their migration flight.

 

Boston Area
September 5, 2018:

Sudbury River Nighthawks with Drumlin Farm

Open vistas along the Sudbury River offer perfect vantage points from which to scan the sky for nighthawks. The group will explore the marsh, grassland and orchards for other fall migrants.

 

 

Conservation Success Stories: The Osprey

Ospreys are on the rebound after a troubled past. Despite a history of pesticide poisoning, persecution, and population declines, Ospreys have returned as one of the most abundant raptors of the coast. Today, the Osprey’s story stands as a testimony to the power of scientifically-informed environmental activism.

An Osprey stands watchfully on a snag over a marsh. Photo © William Freedberg 2015

DDT: A Silent Threat

Osprey numbers crashed dramatically following the widespread use of DDT, a pesticide deployed across America in the 1940s. While previous decades saw Ospreys hunted as “pests” and their wetland habitats drained for development, the introduction of DDT all but rang the death knell for the entire US Osprey population.

Nobody realized it at the time, but DDT builds up in animals’ body tissue, and persists in the environment years after being sprayed on farm fields. This spelled trouble for birds of prey: while DDT spraying rarely poisons adult birds to death, it destroys the structure of raptors’ eggshells, preventing them from reproducing.

As a result, Ospreys declined by over 90% between 1950 and 1970. When the now-famous environmentalist Rachel Carson finally named DDT as the culprit in her book Silent Spring, the discovery ignited a movement. A coalition of the National and Massachusetts Audubon societies, as well as local land trusts and nationwide advocacy groups, intervened on behalf of all species threatened by DDT. They sued the Environmental Protection Agency to ban the pesticide—and won.

A few decades later, Ospreys are almost back to their pre-DDT abundance.

A Place To Nest

The DDT ban eliminated a significant threat to Ospreys, but the bird didn’t immediately bounce back. Even in places with clean water and plenty of fish, Osprey numbers are naturally limited by the number of appropriate nest sites. They normally require a tall, dead tree at the edge of a marsh, but lacking standing trees in the open, they settle for utility poles or other problematic locations.

Artificial nest platforms are one solution. In addition to keeping Osprey nests away from telephone wires and buildings, nest platforms increase the number of Ospreys any wetland can support. With wetland edge habitats constantly losing ground to development, it’s critical to maximize the number of Osprey nesting in appropriate wetlands.

Mass Audubon Continues To Support Ospreys

Mass Audubon’s South Coast Osprey Project maintains about 100 Osprey nest platforms. The project also monitors and records data on the Osprey population, including banding and tagging several birds, and tracking their movements. The data never fails to yield exciting results— whether demonstrating Ospreys’ reliance on the spring herring migration for food, or revealing variability in Ospreys’ choice of wintering grounds (South Shore birds end up in places as far away from one another as Cuba and Bolivia).

If you love Ospreys as much as we do, consider sponsoring a nest platform!

The Ten Craziest Massachusetts Bird Noises

If you’ve never heard a male Snowy Egret nasally bubble away at a rival, well, you are in for a treat.

Using Xeno-canto, an online library of bird sounds to which anyone can contribute, we’ve chased down the strangest recordings of species native to Massachusetts. Hit the play button in the clips below to check them out!

In the first half of this post, we’ll run through some strange bird noises that are easy to go out and hear for yourself.

We’ll review even weirder noises in the second half, but ones that are hard or impossible to experience in Massachusetts. This second section is devoted to noises that migratory birds make on their breeding grounds far to the north, or in other parts of their range.

Part 1: Sounds You Can Hear in Massachusetts

1. American Bittern:

Distant relatives of herons, bitterns make a booming, gulping noise while pumping their necks up and down, giving them the nickname “thunder-pumper.” Hit the play button in this clip and turn up the bass!

An American Bittern stands tall among marsh grasses. Photo (c) William Freedberg

2. Bobolink:

A once-common sound of farm fields and grasslands, the Bobolink’s song incongruously brings to mind R2-D2 from Star Wars.  These grassland birds abounded during the height of low-impact agriculture in New England, but farmland loss, development, intensive harvesting and pesticide use have reduced their numbers dramatically.  With recent conservation programs like the Bobolink Project, which pays farmers directly to protect grassland birds, this species’ future is looking a little brighter.

 

3. Veery:

Veeries are drab, russet-colored thrushes with an outsized voice. They can produce several clear tones at once, and almost sound like they are harmonizing with themselves. While uncommon near developed areas, this birds are one of the most numerous summer birds of deep forest far from the coast.

 

4. Barred Owl:

Owls don’t just hoot—they also can yelp, screech, and shriek. This Barred Owl transitions from a high-pitched wail (which may be a regionalism or an alarm call) into its lower and more commonly-heard “who-cooks-for-you-all.”

 

5. Common Loon:

Perhaps the most iconic sound on this list, the wail of the Common Loon is practically synonymous with the wilderness of northern New England (although they also breed in central Massachusetts). In this recording, listen for their yodels at the beginning, a loud wail at 0:31, and keening starting at 0:09 and 0:58.

Part 2: Sounds Massachusetts Birds Make Elsewhere

6. Snowy Egret:

This might be the weirdest one on the list. Graceful Snowy Egrets are common in New England saltmarshes, but rarely vocalize away from rookeries. At rookeries, however, they’re known for a cartoon character-like and downright hilarious.

A Snowy Egret patrolling the shallows for prey. Photo (c) William Freedberg

7. Pectoral Sandpiper:

Pectoral Sandpipers and many other species of shorebirds seem like much different animals on their breeding grounds than on the east coast during migration: they become quite fearless and territorial, their plumage takes on dramatic patterns, and they sing with a surprising variety of chortles, whoops and whistles. This Pectoral Sandpiper’s song sort of sounds like… somebody blowing bubbles?

 

8. Turkey Vulture:

Turkey Vultures almost never vocalize. When they do, all that comes out is a raspy, sizzling hiss, like adding water to a hot pan.

 

9. Atlantic Puffin:

While puffins are uncommon winter visitors to the waters off MA, you can easily hear their characteristic grumbles on breeding colonies in Maine.

 

10: Great Shearwater:

These pelagic, albatross-like birds are frequently encountered on whale watches and offshore boat trips in Massachusetts waters. While silent at sea, they’re… really quite vocal on breeding colonies, where they sound like rubber chickens brought to life.

A Great Shearwater, true to its name, glides tight to the waves. Photo (c) William Freedberg

These are just our picks for the strangest noises made by local birds… but there are so many other options, it’s hard to winnow them down to just a few!

What would make your top ten? Let us know in the comments!