Connecticut State of the Birds 2013: Authors & Excerpts
Connecticut State of the Birds 2013
The Seventh Habitat and The Decline of Our Aerial Insectivores
Authors and Excerpts
“The Seventh Habitat”
by Stephen B. Oresman
Chairman Emeritus, Connecticut Audubon Society
“There is a seventh habitat … which none of us have ever walked through and which is probably the least known and certainly the least studied. That is the aerial habitat. …. Evidently it is full of small organisms, mostly tiny arachnids …. It has been estimated that a square mile of sky from 20 feet to 500 feet contains 32 million arthropods.”
Eastern Phoebes are among the flycatchers in decline. Photo by Melissa Groo/Melisagroo.com
“The Mysterious Decline of Aerial Insectivores”
by Jon D. McCracken
Director of National Programs, Bird Studies Canada
Possible causes for the 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; and reduced availability of dietary calcium because of acid rain.
“Answers are most likely going to come from the creation of international collaborative networks of scientists, who team up together to focus on one or more research questions.”
“Because most aerial insectivores are still common and have large breeding ranges, the chances of any of them becoming extinct in the next couple of decades seem quite remote. We still have time to figure this out. That’s the good news.
“The bad news is that unless rates of decline are halted or reversed in a timely way, total population collapse eventually becomes something of a mathematical certainty. Even more worrisome are the profound sociological and economical implications that might be facing us if it turns out that declines of aerial insectivores are being driven by changes happening to populations of flying insects.”
“In Thin Air”
Milan G. Bull
Senior Director of Science and Conservation, Connecticut Audubon Society
“Swifts and nighthawks are feeding in the upper layers, sometimes 400 feet high and higher, while Barn Swallows skim the surfaces of lakes and meadows.”
“…although the sky appears transparent, we are actually sitting beneath an enormous mass of animals, day and night – a biomass cloud that we are just beginning to understand and appreciate.”
“Using radar, the scientists (In Britain) calculated that if you add up all the insects passing above you in a .6 mile column of air during a typical spring and summer month, it would add up to over three billion insects.”
“Thoughts on the Air and the Birds that Makes Their Living There”
David Ward Winkler
Professor, Ecology and Evolutionary Biology, Cornell University
“It may be that insects across the board are responding to warmer springs and summers in the north by shifting their emergence earlier in the year, thus reducing the availability of aerial insects in late summer and early fall, just when aerial insectivores need high quantities of food to fuel molt and migration.”
“Chimney Swifts in Connecticut”
Margaret Rubega, Associate Professor, University of Connecticut; Connecticut State Ornithologist
Shannon Kearney-McGee, Avian Population Analyst, Connecticut DEEP, Wildlife Division
Tanner Steeves, Research Assistant, School of Public Health, Yale University
“A Chimney Swift eats hundreds of insects a day, taken only out of the air while flying at high speed.”
“Partners in Flight estimates, on the basis of Breeding Bird Surveys, that there are about 15 million Chimney Swifts in North America…. Yet Partners in Flight also classifies them as a ‘Common Species in Steep Decline.’ “
“The Purple Martin, A Classic Aerialist”
John Tautin
Executive Director, Purple Martin Conservation Association
“Today, the Purple Martin … depends entirely on people, called Purple Martin ‘landlords,’ to provide it nesting cavities in the form of familiar apartment-type birdhouses or clusters of natural or artificial gourds that one sees around the countryside. For their efforts, successful landlords enjoy constant action and song at their sites, and they have the satisfaction of contributing to the species’ well-being.”
“Bulbat in the Sky: The Legacy of a Loser?
Wayne R. Peterson
Director of Important Bird Areas, Massachusetts Audubon Society
“…the Common Nighthawk is a rare and local nesting species in many parts of the region. … In Connecticut, a dedicated effort to locate breeding Common Nighthawks during the period 2005-2007 was unable to confirm the presence of a single nesting pair.”
“Master Aerial Insectivores: Bats”
Jenny Dickson
Supervising Wildlife Biologist, Connecticut DEEP
“As a group, bats are the single largest predator of night-flying insects. They provide tremendous nightly insect control services that have significant ecological – and economic – impacts.”
