Category Archives: Climate Change

Field Notes: Southern Breeding Birds Are Moving North

“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 20th 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.

Rising Seas are Flooding Saltmarsh Sparrow Nests. Can They Adapt?

A recent study showed that Saltmarsh Sparrows choose nest sites based on past experiences. If a pair’s nest floods, for example, they’ll build their next on higher ground.

While this behavior might seem to show resilience to rising seas and climate change, the authors note that populations have still declined by over 75% since the 1980s.

In fact, nesting further away from the water a risky proposition for Saltmarsh Sparrows, and flooding is not the only threat to their nests. As with any species threatened by climate change, what appears to be a successful adaptation to environmental change often turns out to have unforeseen repercussions for the species.

A Saltmarsh Sparrow in the cordgrass (Spartina sp.) of a New England Marsh. Photo by Shawn Carey.

Caught Between a Fox and a Hard Place

Nesting further from the high-tide mark comes with trade-offs. Nests over drier ground are most vulnerable to predators, which are the second-greatest cause of nest failure in Saltmarsh Sparrows aside from flooding. Small carnivores like raccoons, foxes, and even snakes have been spotted feeding on Saltmarsh Sparrow chicks in nests far from the water’s edge.

Ticks, isopods, and other parasites also prefer drier nests. Some tidal flooding deters invertebrate pests, and may actually contribute to nestling survival as long as the nest isn’t completely inundated.

Nests are most likely to be successful in a narrow band near the high-tide mark where they are safe from predators, parasites, and flooding. Researchers found that Saltmarsh Sparrows that lost their nests to predators would re-nest closer to the waters’ edge, just as birds with flooded nests would move to higher ground. But as increasingly severe storms now regularly push spring tides past their normal height, they wash over what was once the “sweet spot” between safety from predators and safety from flooding.

So, even though Saltmarsh Sparrows adjust their behavior to manage risks, they’re still only resilient to mild disruptions like steady and gradual sea level rise. Regularly-occurring extreme floods, coupled with

Saltmarsh Sparrows are in Trouble

Climate threats to Saltmarsh Sparrows are borne out by the data. Their population is currently around 30,000 birds– half of what it was in 2010, and a shadow of the original population of 250,000. They continue to decline at around 9% annually nationwide, but in Massachusetts, careful management of saltmarshes has kept their numbers comparatively stable. 

Climate change is not the only issue facing Saltmarsh Sparrows. Over 1/3 of Massachusetts’ coastal wetlands have been developed. Dikes, railways, and other infrastructure disrupts the drainage of many remaining saltmarshes, raising the threshold for flooding but causing them to retain floodwaters for longer periods.

Mass Audubon continues to monitor Saltmarsh Sparrows in Massachusetts and advocate for the species, including submitting a proposal to list them as an Endangered species at the state level in 2017.

For tips on combating climate change, find out how to reduce your carbon footprint. For more information on Saltmarsh Sparrows, feel free to ask us a question in the comments!


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

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

Evening Grosbeak (Creative Commons)

Irruption Years: Boom And Bust

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

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

Shifting Distributions

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

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

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

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

This Year’s Conditions

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

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

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

Where Do Woodcocks Go In The Snow?

When winter weather drags on into late March, our earliest spring migrants still show up on schedule!  Birders often hear the sharp, reedy “peent!” of American Woodcocks in mild weather amid other spring sounds, like the clamor of wood frogs and spring peepers. Hearing them calling from fields covered in several feet of snow can seem incongruous. So how does lingering snow affect these enigmatic birds’ ability to find food?

Beak Superpowers

Woodcocks find insects by probing underground with their beaks. The tips of their beaks pack a bundle of highly sensitive nerves, which they use to pick up on vibrations from insects moving in the soil.

The tip of their beak can also flex open while the rest of it stays closed, allowing woodcocks to delicately pick up food without having to pry their whole bill open underground. The ability to open just the end of the beak is called distal rhyncokinesis  (rine-co-kin-EE-sis), or simply rhycokinesis  when discussing beak flexibility more generally. It’s a trait shared by many members of the sandpiper family, woodcocks included.


This photo only partially shows how flexible the tip of a woodcock bill is– underground,  they can close the lower two thirds and move just the outer third. (Photo: Will Freedberg) 

 

With such particular feeding habits, spring snowstorms might seem to spell trouble for these ground-dwelling insect-eaters. In particular, 2018 has seen a spate of nor’easters barreling through New England, dumping foot after foot upon snow.

Snowed-in Woodcocks Seek Open Ground

Woodcocks can often feed successfully through a shallow layer of snow, but only if the ground is not frozen through. If the ground has already thawed, a covering of snow will in fact keep the ground from freezing fully again, if temperatures return below freezing.

But March 2018 has seen snowpack deeper than a woodcock’s bill is long, even when the ground hasn’t been frozen solid. In years like this, woodcocks feed near any natural features that keep snow off the ground—along the banks of streams and flowing water, or under coniferous trees that partially shelter the ground from snow.

Birders in the know will look for them in these areas, and are careful not to scare or flush these easily-stressed birds. Their flight displays have continued along the edges of fields so far regardless of snow cover, and should keep going into April.

For more tips on how to find woodcocks, check out our list of sites and programs!

Species Spotlight: Ovenbird

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!

Species Spotlight: Northern Bobwhite

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!

On the Road: National Adaptation Forum

by Daniel Brown and Jeff Collins

Jeff Collins, Director of Conservation Science, and Daniel Brown, Climate Change Program Coordinator, attended the National Adaptation Forum (NAF) in May in Saint Paul Minnesota.

The National Adaptation Forum is a gathering of scientists, educators, and community leaders working to address the challenges of climate change.

The field of climate adaptation is advancing rapidly, and Daniel presented on Mass Audubon’s work with communities to identify local critical weather thresholds. Thresholds are used to plan for emergencies and design infrastructure, but those thresholds are often outdated and difficult to measure. On top of that, climate change is making extreme weather events change over time, creating a great deal of uncertainty for communities looking to stay safe, healthy, and resilient. That may be soon changing, however, based on the assessment of experts at NAF. Land managers and city planners may soon get a whole host of new tools that will help plan for the size and frequency of future extreme weather.

Some of the most common themes discussed at NAF were environmental justice and the need for ecological conservation efforts to make communities more resilient. For years, the focus has been on what’s called “green” infrastructure—using restored landscape types like parks, greenways, and rain gardens to lessen the effects of climate change. Now the focus seems to be shifting to protecting undeveloped open areas and letting nature provide a resilient, adaptable places for people and wildlife. Mass Audubon’s Mapping and Prioritizing Parcels for Resilience (MAPPR) tool will help with that effort by allowing land conservationists to identify parcels that are a high priority for protection.

Climate change poses many challenges for our communities in the decades ahead. Underserved communities with less access to open space tend to be particularly vulnerable, but the inspiring work of so many institutions across North America gives plenty of reasons to be hopeful.

 

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

Climate Change Symposium

Tufted Titmice have taken Massachusetts by storm in the past thirty years. Copyright John Sill.

Tufted Titmice have taken Massachusetts by storm in the past thirty years. Copyright John Sill.

Bird Conservation staff were in attendance at our climate change symposium last week, to enjoy a two part presentation about the impacts of climate change on the nature of the Northeast United States. Mass Audubon’s Regional Scientist Robert Buchsbaum, described the current and projected impacts of climate change on the nature of New England. Robert discussed changes that have already occurred due to warming temperatures, using examples from salt marshes, fisheries, forests, and vernal pools.

The impacts of warming are particularly evident for birds. Robert presented data from our Breeding Bird Atlases and State of the Birds work, which show that the range distribution of many species has changed. Several species, such as the Tufted Titmouse and Carolina Wren, are experiencing range expansions and are now more abundant throughout Massachusetts. Other familiar species such as Tree Swallows and Black-capped Chickadees are predicted to decrease.

Appalachian Mountain Club’s (AMC) Assistant Research Director, David Publicover, focused on the impacts of climate change in the mountains of the Northeast. The AMC has been collecting weather measurements on Mount Washington’s summit since the 1930’s and this is now used to study climatic trends and their impact on northeastern mountain ecosystems.

This event was part of a series: Climate Change, Energy, and the Outdoors—an educational series co-sponsored by the Appalachian Mountain Club, Mass Audubon, and the Union of Concerned Scientists.