Tag Archives: birds

Species Spotlight: Ovenbird

Posted on October 26, 2017 by Jon Atwood

Ovenbird © Tom Murray

The Ovenbird, whose familiar tea-cher, tea-cher, tea-cher, tea-cher song is a dominant feature of the spring and summer woodlands of New England, was identified in Breeding Bird Atlas 2 as a species on the increase, especially in the central and eastern portions of the state. These increases were thought to reflect increased amounts of suitable forest habitat due to formerly agricultural land reverting to forest.

Change in Ovenbird distribution in Massachusetts between Breeding Bird Atlas 1 (1974-1979) and Breeding Bird Atlas 2 (2007-2011).

But the newly-released State of the Birds report tells a less optimistic story. Ovenbird distribution in Massachusetts is likely to be adversely impacted by projected future changes in temperature and precipitation patterns. By 2050 the species will continue to occur statewide, but occupancy in eastern areas of the state may decline as the species’ climate envelope (their preferred climate) drifts northward, leaving Massachusetts near the southern limit of the species’ continental distribution.

Current climate suitability for Ovenbird in Massachusetts.

Climate suitability for Ovenbird in Massachusetts in 2050.

How to read the climate suitability maps >

Keeping Large Forest Tracts Intact Will Lessen the Stress Ovenbirds May Face

Research has found that Ovenbirds require large intact expanses of forest habitat for successful breeding. This could be in part due to the fact that larger undisturbed forests have lower risk of nest predation and brood parasitism. Therefore, maintenance of large tracts of mature forest is crucial to future conservation of Ovenbirds in Massachusetts. Such areas will continue to be threatened by suburban development and associated habitat fragmentation.

Additionally, climate change may add to the stress of losing intact core habitat, because warmer temperatures may reduce the soil moisture levels that influence Ovenbird’s food resources (mainly insect larvae gathered on the ground).

Conservation Is Needed for the Full Life Cycle of a Migratory Bird

Distribution of Ovenbirds during breeding (orange), migration (yellow), and winter (blue) periods. © Cornell Lab of Ornithology, Neotropical Birds

Ovenbirds migrate through the southeastern U.S., wintering mainly in the Caribbean, Mexico, and Central America – including areas that were recently damaged by Hurricane Irma. Throughout its annual life cycle it is vulnerable to habitat loss and degradation, window collisions, and predation by cats.

Conservation of Ovenbirds demonstrates the broad suite of actions that are important for most

of our Neotropical migrant songbirds. Efforts to reduce losses throughout the full annual cycle are important. Action must be taken on their breeding, migrating, and wintering grounds to effect positive change in the population.

How Can We Help Ovenbirds and Others?

Prevent forest fragmentation in the breeding range by supporting the efforts of local land trusts.
Ensure that your backyard is a bird-friendly sanctuary safe from cats and potential collisions with windows.
Support efforts to reduce window collisions at tall skyscrapers and other office buildings.
Donate to organizations focused on protecting lowland forest habitats in the Caribbean, Mexico, and Central America—actions directed toward all those efforts will help reduce the pervasive impacts of changing temperature and precipitation patterns on breeding Ovenbirds in Massachusetts.

Ovenbirds are often observed strutting (never hopping) like a chicken along the forest floor. © Tom Benson

Please consider supporting our bird conservation work by making a donation today. Thank you!

A Plethora of Pirates: Jaegers rule at Provincetown

Posted on October 19, 2017 by Wayne Petersen

First it was shearwaters—now it’s jaegers!

Earlier this fall the waters off Provincetown made news when an unprecedented concentration of thousands of Great Shearwaters was attracted inshore by a superabundance of small menhaden fish (a.k.a. peanut bunker) that were driven ashore by foraging mackerel. This influx afforded birders, fishermen, and the general public a unique opportunity to see these normally open ocean seabirds at practically arm’s length.

Now, several weeks later, exceptional numbers of jaegers have taken center stage in these same waters. Dusky-colored and predatory, jaegers are gull-like seabirds that in North America nest on high latitude arctic tundra from Alaska to Labrador. Taking several years to mature and exhibiting high variability and a complexity of plumages, jaeger identification can confound even the most experienced observers.

Parasitic Jaeger (dark morph) © Peter Flood

Meaning “hunter” in German, the word “jaeger” (pronounced “yay-ger”) is well-suited to three closely related species—Pomarine, Parasitic, and Long-tailed—all distinctive in adult plumage because of two, long, pointed or twisted central tail feathers. But far more exciting is the kleptoparasitic lifestyle of jaegers. Kleptoparasites are species that obtain much of their food by stealing it from other species, which in the case of jaegers usually means smaller seabird species such as terns.

A Parasitic Jaeger pursues a Common Tern © Peter Flood

Parasitic Jaegers are the new rulers of the waters off Provincetown

In Provincetown it is Parasitic Jaegers that have been maintaining dominion over the hapless terns lingering off Race Point in recent weeks. Literally dozens of jaegers are currently tracking the hard-working terns off Race Point, the ever vigilant pirates constantly on the lookout for terns carrying fish in their beaks. Upon spying a fish-laden victim, a plundering jaeger will at once give aggressive chase. With fighter plane-like precision, one or more jaegers will pursue a target with aerial gymnastics hardly seen in any other bird species. So skillful at piracy are jaegers that they are often able to catch a falling fish relinquished by an intimidated tern before the fish hits the water!

A Parasitic Jaegar prepares to catch relinquished fish © Peter Flood

In the days ahead as the last of the lingering terns head for South America for the winter, the aerial pirates that have been recently harassing them off Provincetown will begin to drift away, shadowing the terns all the way to their South Atlantic wintering quarters. Although Parasitic Jaegers are capable of capturing fish or scavenging food on their own, during their non-breeding season at sea they generally prefer their criminal life style as a way to obtain food. Come spring however, the jaegers will head north for their arctic nesting grounds where their diet will shift to small rodents or shorebird eggs and chicks.

Always predatory and always on the move, jaegers are fascinating seabirds that can only be admired when viewed in full pursuit of a fleeing tern, or when observed deftly flying amid the frothy troughs of a storm-tossed sea.

Get to P-town soon to see these spectacular birds for yourself!

Parasitic Jaegers pursue a tern © Peter Flood

Please consider supporting our bird conservation work by making a donation today. Thank you!

Species Spotlight: Northern Bobwhite

Posted on October 13, 2017 by Jeff Ritterson

Climate change, like all environmental change, is bound to create losers and winners. That is, while some species will experience climate-driven declines, others stand to benefit. The Northern Bobwhite is one species that may be positively affected by climate change, according to Mass Audubon’s new State of the Birds report.

Northern Bobwhite range in North America ©National Audubon

The Northern Bobwhite is a species which reaches the northern fringe of its range in southeastern Massachusetts. According to the Massachusetts Division of Fisheries and Wildlife, Northern Bobwhites were once limited to coastal areas of Massachusetts, but likely expanded statewide following the clearing of land for agriculture during the 1820’s to 1840’s. However, a string of severe winters in the late 1800’s and early 1900’s may have wiped out bobwhites across the state, recovering only in the southeast which has milder winters.

Change in Northern Bobwhite distribution between Breeding Bird Atlas 1 (1974–1979) and Breeding Bird Atlas 2 (2007–2011).

Why Do Severe Winters Hurt Northern Bobwhites?

Northern Bobwhites gather together and form “coveys” in the fall and winter. © Missouri Department of Conservation

Recent research has confirmed the long-standing assumption that severe winter weather events (e.g., ice storms, heavy snow accumulation) can increase Northern Bobwhite mortality and thus suppress northern populations of bobwhites.

One hypothesis explaining the negative effect of severe winter weather on Northern Bobwhites is that too much snow accumulation can limit access to the bare ground, where they forage primarily for seeds. Unlike turkeys, bobwhites cannot dig through snow to find food.

Predicted Less-Severe Winters Could Help Bobwhites in Massachusetts in the Future

Massachusetts can expect to see less snow fall and less accumulation in future winters due to climate change, and this may bolster winter survival of Northern Bobwhites and allow them to expand their distribution from the southeast to other areas of the state.

However, although the climate may be more favorable for bobwhites, as shown by our maps below, successful colonization of new areas will depend on the availability of suitable habitat, such as early successional areas, scrubby field edges, and open woodlands with herbaceous ground cover. Without this, the Northern Bobwhite may continue to decline in the state.

Mass Audubon’s work on the Foresters for the Birds program (of which Northern Bobwhite is a focal species) and habitat management on our sanctuaries are critical for the conservation and restoration of healthy forests and early-successional habitats and species in the state.

Climate Suitability for Northern Bobwhites

Current climate suitability for Northern Bobwhite

Projected climate suitability for Northern Bobwhite in 2050.

How to read the climate suitability maps >

Please consider supporting our bird conservation work by making a donation today. Thank you!

Flight of the Broad-wing: an epic in the sky

Posted on September 19, 2017 by Wayne Petersen

Every year, at about this time, dedicated hawk watchers and serious raptor aficionados begin paying particular attention to radar images and weather prognostications on the evening news. Indeed, some devotees even regularly take their vacation in the middle of September. So what’s so special about mid-September? To those in the know with an interest in hawk migration, mid-September is THE time to intercept the peak southward departure of the Broad-winged Hawk (Buteo platypterus).

Adult Broad-winged Hawks are 15 inches-long with a 24 inch wing-spread, a black tail crossed midway with a single wide, white band, a brown back, and rusty-brown underparts. In flight they are compact, with broad wings that are pale underneath and traced with a thin black border around the edges (as shown in the above photo). Ranging throughout most of the eastern United States and southern Canada west to Alberta, Broad-wings spend much of their summer hunting amphibians, snakes, small mammals, and birds to feed their young. However in mid-September it is the spectacular autumn migration of this species that annually captivates and mesmerizes hawk watchers, and often even the general public as well.

Unlike other raptors (or most other species of birds for that matter) few have such a telescoped seasonal departure as the Broad-winged Hawk. With seemingly mathematical precision, much of the North American breeding population typically initiates its southward migration sometime between September12–20. Depending upon weather conditions, in some years this time window becomes even more compressed, occasionally with many thousands of individuals passing favored observation sites literally within a few hours. Here in Massachusetts, Wachusett Mountain in Princeton, Mt. Watatic in Ashburnham, and Mt. Tom in Holyoke are among the better places to witness this phenomenon.

In mid-September Broad-wings across much of their breeding range wait strategically for the passage of cold fronts accompanied by falling temperatures and light winds from the north side of the compass to begin their migration. Under such conditions the hawks almost simultaneously begin lifting up from the summer woodlands where they nested to search for rising warm air masses called thermals that will help eventually transport them to South America for the winter.

Using such thermals to carry them skyward many thousands of feet, eventually the Broad-wings break out of the thermals and travel to another thermal, often several miles away, by means of long, high-speed power glides that cause them to gradually lose altitude at the same time. Once they reach another thermal, they then ride the new “escalator” skyward. Because hundreds of Broad-wings are using this same strategy, on a good day for migration, a large thermal often contains many hundreds of tightly soaring individuals all rising upwards at the same time. In hawk parlance such an aggregation is called a “kettle” (shown below).

On days favorable for migration, many thousands of Broad-winged Hawks make their way southward at the same time using this combination of riding warm air thermals upward for lift, and then power gliding to another thermal so they can regularly cover hundreds of miles a day under ideal conditions. The migration tends to follow the southwesterly leading line created by the Appalachian Mountains. Between the thermal-and-glide strategy, and wind lift created along Appalachian ridgetops, the hawks gradually make their way to the Gulf Coast, where they gradually “turn the corner” in southern Texas to avoid crossing the Gulf of Mexico, and then make their way into Mexico and south through Central America, and finally into northern South American where most will spend the winter.

Not surprisingly there are variations in this strategy along the way, including several world-famous hawk-watching bottlenecks where, with several other species, they pass through Mexico, Costa Rica, and Panama. While this is by no means the full story, it is the essence of how each year this magnificent raptor accomplishes one of the most amazing autumn migrations in the western hemisphere.

Please consider supporting our bird conservation work by making a donation today. Thank you!

Hot Off the Press! State of the Birds 2017

Posted on September 12, 2017 by Margo Mercer

Black-capped Chickadee may face an uncertain future in Massachusetts. ©Bill Thompson, USFWS

It is with great pleasure that we announce that our third edition of State of the Birds is now available. State of the Birds: Massachusetts Birds and Our Changing Climate focuses on what the future may hold for the breeding birds of Massachusetts as the climate continues to change.

Our last two State of the Birds reports, released in 2011 and 2013, compared the past to the present and identified changes in Massachusetts bird populations. The 2017 edition builds on that work by using science to predict the future.

Climate Matters For Birds and People

Most birds have limited distributions and, to some extent, climate controls the range of those distributions. To glimpse the future, we used a statistical analysis called climate envelope modelling.

Put simply, climate envelope modelling uses real bird and climate (various measures of temperature and precipitation) data to define the preferred climate of a bird species—their “climate envelope”—as it is today. Then the models substitute predicted values of the climate variables into the equation to project a bird’s climate envelope in 2050.

Using the results of our analysis, we assigned each of the 143 species analyzed a “Climate Vulnerability” score. There were some expected results and some surprising results. The overarching message was that birds are already feeling the effects of climate change and even some of our most common birds will probably experience further changes by 2050.

It’s In Our Power to Change the Future

While climate change can feel like an overwhelming problem, it is a problem that we can solve. Much like Scrooge in A Christmas Carol, we are being shown a possible future for our birds, and, just like Scrooge, we can take action today to change that future.

Visit the website, download the report, and share it with your friends and family. If we work together we can protect birds, wildlife, and ourselves.

Check out the article in the Boston Globe about the State of the Birds report.

Please consider supporting our bird conservation work by making a donation today. Thank you!

Beachfront Armageddon: A fish tale and a seabird saga

Posted on September 12, 2017 by Wayne Petersen

For several weeks the sandy beaches at Race Point and Herring Cove Beach in Provincetown have witnessed a spectacular and practically unique confluence of seabirds and fish. The players in the P-town saga have been Atlantic menhaden (Brevoortia tyrannus) and Great Shearwaters (Ardenna gravis).

Great Shearwaters are Ring-billed Gull-sized seabirds that maintain their breeding terminus at Tristan de Cunha, a remote archipelago located deep in the southern hemisphere approximately halfway between the tip of southern South America and Cape Horn in South Africa. Annually most of the world’s population of Great Shearwaters migrates north across the equator to spend the austral winter in the northwest Atlantic Ocean. By late summer most of the adult population has begun the long return journey back to Tristan du Cunha to nest, but the non-breeding sub-adult population regularly remains in North Atlantic waters until late fall. While in the northern hemisphere Great Shearwaters typically remain on remote fishing banks far off the New England and Atlantic Canadian coasts where they forage on baitfish such as sand lance, capelin, sea herring, or squid and fish bycatch obtained by tracking commercial fishing vessels.

Each high tide left behind a swath of dead menhaden.

Menhaden are a super-abundant forage fish often characterized as one of the most commercially important fishes occurring along the Atlantic coast of the United States, particularly from Massachusetts to the Carolinas (Bigelow and Schroeder’s Fishes of the Gulf of Maine, Collette & Klein-MacPhee, eds., Smithsonian Press, 2002). Due to their super abundance, immature Menhaden typically less than 2” in length are important fodder for a variety larger predatory fish, marine mammals, and seabirds. For reasons not always clear, the literature suggests that they are periodically subject to mass late summer stranding and mortality events. These mortality events most often occur in shoal water habitats such as the heads of tidal creeks or small coves like the Herring Cove area in P-town where they may suffer from oxygen depletion or are driven ashore by predators (op.cit.).

Regardless of the explanation, a massive menhaden mortality event took place during the last couple weeks of August and early September. Most notable however was the fact that unprecedented numbers (i.e., many thousands!) of Great Shearwaters appeared inshore to feast on the abundant fish. For many days in a row, on each falling tide the voracious shearwaters literally swarmed in the surf picking off the tiny fish like popcorn. For a normally completely pelagic species that spends most of its life out of sight of land, this behavior was most unusual and provided birdwatchers, fisherman, and beach-goers a rare opportunity to observe these interesting seabirds at literally pointblank range!

Check out this video to see what this phenomenon looked like.

The Treasure Islands of Essex County

Posted on July 20, 2017 by Margo Mercer

by Chris Leahy, Gerard A. Bertrand Chair of Natural History and Field Ornithology emeritus

There is something about islands. Their remoteness generates a certain mystique. Even islands inhabited by people have an aura of “away-ness,” and uninhabited ones stimulate visions of hidden treasures of one kind or another. There is also an ecological significance to islands: their plants and animal communities are often different from those of even nearby mainlands; their isolation from other populations promote evolutionary change; and they may act as refuges for certain species because they are hard to reach by predators.

The coastal waters of Essex County from Nahant Bay to Cape Ann are dotted with more than 50 islands ranging in size from small rocky “skerries” which are nearly submerged at high tide to the well-wooded 83-acre Great Misery Island, two of them populated at least seasonally. In 2002 these were formally designated as the Essex County Coastal Birds Islands Important Bird Area*, due to their breeding populations of water birds that rarely nest on the mainland, including a number of rare or uncommon species.

This summer Mass Audubon’s Conservation Science Department, supported by a grant from the Nuttall Ornithological Club, and the help of several generous private boat owners began a survey of these islands with the following basic objectives:

Developing a comprehensive understanding of past and current bird survey efforts, data sources, and management activities.
Completing an assessment of current breeding bird activity on the islands.
Identifying existing stresses such as human use, presence of rats and other predators, vegetation change, and climate vulnerability.
Developing recommendations for future management in support of the breeding birds.
Raising public awareness of the importance of these islands through programming and networking with state and regional conservation entities.

The survey has already turned up a number of previously unrecorded breeding sites for wading birds and American Oystercatcher. We will be publishing more detailed results in the near future.

*An Important Bird Area (IBA) is an area identified using an internationally agreed upon set of criteria as being globally important for the conservation of bird populations. The program was developed and sites are identified by Birdlife International based in Cambridge, England. Currently there are over 12,000 IBAs worldwide and 79 in Massachusetts.

Please consider supporting our bird conservation work by making a donation today. Thank you!

In the Field: Elm Hill

Posted on July 19, 2017 by Jeff Ritterson

Past blog posts about our Elm Hill Sanctuary – a Foresters for the Birds demonstration site—have largely discussed the planning of forestry practices to manage and enhance bird habitat. We kicked the project off last fall and winter, when our migratory birds were hundreds or thousands of miles away. So, until spring arrived, we were not able to work much with the birds themselves.

A primary focus of the program is indeed birds and their habitat, so it is important to assess how effective any implemented forestry practices are. This enables us to make adjustments to future management and maximize the benefit for birds. We do this by monitoring how the birds respond. At the earliest, on the ground management at Elm Hill will not happen until this coming winter. However, we will need to compare the future bird response to current, baseline conditions. A before-and-after, if you will.

Late May through early July is the ideal time to sample breeding birds. Migration is over, so all the birds have arrived and will likely remain through the season. They are on breeding territories and actively singing, which helps us to detect their presence. During this time we can begin to answer some important questions.

For example, which species are present, and what are their general habitat preferences? How many species are present? How many individuals of each species are present? Is a particular species absent that we may have expected? Answering questions like these help us to characterize the current bird community. Answering the same questions after habitat management will help us assess just how effective our efforts were.

This is why, with the help of volunteers, Sheila Carroll and Mark Lynch, we recently completed a series of point count surveys at Elm Hill, all within areas that are slated for management in the near future. With this initial information in hand, we will eventually see how things change after management, which is geared towards helping species in need of conservation action. The next step will be to dig into the data, and some results will be shared in future Elm Hill updates. Stay tuned!

Please consider supporting our bird conservation work by making a donation today. Thank you!

How birds sing such intricate songs

Posted on June 7, 2017 by Jeff Ritterson

The colorful bursts of flowers and the familiar smell of thawing soils that we all associate with spring is always accompanied by the wonderful sound of bird song. There is nothing quite like waking early enough to experience the dawn chorus, where male birds, representing a slew of different species, are persistently singing to secure a breeding territory and attract a mate for the season.

The beauty and complexity of these songs is attributable to a unique organ that most birds possess, called a syrinx. Located where the trachea – commonly known as the windpipe – splits into the bronchial tubes before entering the lungs, the syrinx has two symmetric halves, each capable of producing sound independently. This enables songsters to make seamless changes in pitch, articulate a complex burst of short notes, and even sing two tones at once.

Some of our most impressive singers are the thrushes. This family (Turdidae) includes species such as the American Robin and Eastern Bluebird, but perhaps the most impressive singers are those which inhabit deep forests. Some of these songs, such as the Wood Thrush’s and Veery’s, are featured on the following website, where you to listen at regular speed as well as slowed down:

http://www.wildmusic.org/animals/thrush

When you slow the songs down you can really hear the intricacies. Put some headphones on to really have a close listen, and maybe you will have a fuller appreciation the next time you hear a bird singing.

Please consider supporting our bird conservation work by making a donation today. Thank you!

The Bobolink Project: 2017 season update

Posted on May 10, 2017 by Margo Mercer

The Bobolinks are arriving in New England and we’re finalizing the contracts with our participating Bobolink Project farmers. Thanks to the generosity of our Bobolink Project donors, we can protect over 630 acres of farmland this year! In return for some compensation, the Bobolink Project farmers will delay mowing on their hay fields until the young grassland birds have had time to fledge.

As in past years, we had more acres submitted into the project than we could cover with the available pool of donations. This year, we received 40 applications from farmers in Vermont, Massachusetts, New Hampshire, Maine, and New York—but our donation pool, as of April 1^st (our deadline for donations), could cover only 17 of the farmers’ fields. This may sound disappointing, but we are able to cover 20% more acres this year at a lower per acre price of $60 (vs. $75 last year).

We are glad that the project is continuing to grow and look forward to welcoming grassland birds to fields enrolled in the program this summer and sharing our results with you. Keep up to date with The Bobolink Project by signing up to the mail-list or follow us on Facebook.

The Bobolink Project donations are accepted all year. The 2018 donation pool is already growing: since April 1^st we have received over $8,000 in donations that will be saved for next year. Donate now to help us protect more acres and birds next year.