Connecticut Audbon Society

News Release: Connecticut State of the Birds 2013 – Long-term Population Decline is Decimating Aerial Insectivores

Tree Swallows are among the aerial insectivores that breed more successfully in areas with man-made next boxes. Photo by Melissa Groo/

Fairfield, Ct., Feb. 22, 2013 – Concerned with the dramatic decline of 17 species of birds that nest in Connecticut and eat only insects caught while flying, Connecticut Audubon Society today called for a multi-agency program of research and assessment along with immediate remedies such as cuts in pesticide use and the creation of man-made nesting sites.

The recommendations and action plan are contained in the Connecticut State of the Birds 2013 report, “The Seventh Habitat and the Decline of Our Aerial Insectivores.” Released annually since 2006 by Connecticut Audubon Society, Connecticut State of the Birds has become the leading research-based assessment of conservation conditions in the state.

The 17 species – known as aerial insectivores because they eat bugs on the wing – include beautiful and well-known birds such as Barn Swallows, Whip-poor-wills, Common Nighthawks, Chimney Swifts, Purple Martins and Tree Swallows.

They are suffering from a long-term population decline that, if unchecked, threatens their survival. The report also contains an article about a similar decline in Connecticut’s bat population, which is also entirely reliant on aerial insects.

Aerial insectivores forage in the “seventh habitat” – the relatively unstudied expanse of air above the earth. Billions of insects, arthropods and other bugs inhabit that space in a shifting mass sometimes referred to as aerial plankton (beaches and offshore islands, tidal marshes, shrublands, grasslands, inland wetlands and forests are the other six.)

Connecticut State of the Birds 2013 notes, in an article by Jon McCracken, director of national programs for Bird Studies Canada, that aerial insectivores are still common enough that extinction is unlikely over the next couple of decades.

“But as Jon reports, unless we reverse the trend, population collapse is something of a mathematical certainty,” said Milan Bull, senior director of science and conservation for Connecticut Audubon Society. “The implications will be even more profound if it turns out that the main cause of the collapse is related to changes in aerial plankton.”

Connecticut Audubon Society will work with local organizations to establish more Purple Martin colonies. Photo by Melissa Groo/

Connecticut State of the Birds 2013 was conceived and edited by Bull and by Stephen B. Oresman, chairman emeritus of Connecticut Audubon Society’s Board of Directors.

CAS released the report at a news conference in Fairfield on Friday, February 22. CAS staff were joined by Susan Whalen, deputy commissioner of the state Department of Energy and Environmental Protection; Kathy Van Der Aue, vice president of the Connecticut Ornithological Association; and Shannon Kearney-McGee, an avian population analyst with the DEEP. Former television host Phil Donahue, who has successfully established Purple Martin colonies on his Westport property, also participated.

Read the report here.

Watch the news conference here.

You can read a list of authors and excerpts here.

You can find links to news coverage of the report in the Connecticut Post, Norwalk Hour, Danbury News Times and WCBS 880 here.

Causes of the Decline of Aerial Insectivores

Research on aerial insectivores and on the air-borne insects they rely on is sparse. Possible causes of the population decline include:

  • fewer man-made nesting sites such as barns, open chimneys and gravel roof tops;
  • loss of open-country foraging habitat;
  • changes in the availability of insects, perhaps because of climate change;
  • exposure to environmental contaminants including pesticides;
  • reduced availability of dietary calcium because of acid rain.

“Our earlier Connecticut State of the Birds reports were based on well-established research, and we were able to make specific recommendations about protecting forest birds or prioritizing conservation strategies,” said Robert Martinez, president of Connecticut Audubon Society. “But the lack of research on aerial insectivores means those kinds of recommendations are harder to make this year.”

Recommendations and Actions
Connecticut State of the Birds 2013 calls on government agencies such as the state Department of Energy and Environmental Protection, academic institutions and conservation organizations to collaborate on a comprehensive assessment of the status of aerial insectivores.

Because the population decline is most severe throughout northeastern U.S. and southeastern Canada, the assessment should be undertaken on an interstate and international basis.

In addition, Connecticut Audubon Society is calling for an increase in aeroecology research, and greater sharing of research and data through workshops and conferences to understand the research being conducted, by whom, and what still needs to be accomplished.

In the shorter term, Connecticut Audubon Society will work with other conservation organizations to help pass pesticide reduction bills in Hartford. In particular, CAS will support a bill to ban the use of pesticides in municipal parks.

The decline in Barn Swallows might be partly attributable to the loss of open-country foraging areas. Photo by Melissa Groo/

Connecticut Audubon Society will also work with four to six local organizations to create new Purple Martin colonies, a proven method of increasing the number of nest sites. CAS maintains a successful martin colony at its Milford Point Coastal Center and is attempting to establish another at its Stratford Point coastal restoration site.

According to the U.S. Fish and Wildlife Service, significant population declines in the eastern United states have been observed since 1966 in Bank Swallows, Common Nighthawks, Olive-sided Flycatchers, Whip-poor-wills, Chimney Swifts, Eastern Kingbirds, Least Flycatchers, Barn Swallows, Willow-Alder Flycatchers, Purple Martins and Acadian Flycatchers.

Whip-poor-will, Common Nighthawk, Alder Flycatcher and Purple Martin are listed as endangered, threatened or of special concern in Connecticut.






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