Saturday, October 5, 2013

Chim-Chim-in-ey Swifts!

Connecticut Audubon Society helped to monitor a Chimney Swift nest and roost site this summer in Hartford. Watching these amazing birds fly around over the rooftop of the Governor’s Foot Guard Armory on 159 High Street, I soon found myself singing my own version of the popular song from Mary Poppins

Chim chim-in-ey, chim chim-in-ey Chim chim cher-ee!
A swift is as lucky, as lucky can be
Chim chim-in-ey, chim chim-in-ey Chim chim cher-oo!
Good luck will rub off when it swirls above you 

Or blow it a kiss and that's lucky too

Now, as the ladder of life 'as been strung
You might think a swift's on the bottommost rung 
As I watch it flutter around like the ashes and smoke 
In this 'ole wide world there's no 'appier bloke
Chim chim-in-ey, chim chim-in-ey Chim chim cher-ee!
A swift is as lucky, as lucky can be
Chim chim-in-ey, chim chim-in-ey Chim chim cher-oo!
Good luck will rub off when it swirls above you

It has a tail with spiked bristles oh yes it do
Featherless shafts to prop itself ‘gainst the flue
Up where the smoke was once billered and curled'
Tween pavement and stars is the chimney swift world
When it’s the end of the day but not quite night
You’ll see them swirling and twittering in the twilight
About the rooftops of Hartford, oh what a sight!     
                             -Anthony Zemba (with apologies to Richard M. and Robert B. Sherman)

Along with my co-monitors, Jack and Maggie Peretto from the Hartford Audubon Society, we monitored the chimney at the armory starting the last week of April and continuing until just last week. The Perettos and I conducted this monitoring as volunteers for Chimney Swift Watch - a cooperative initiative with the University of Connecticut and the Wildlife Division of the Connecticut Department of Energy and Environmental Protection.

Connecticut's Comprehensive Wildlife Conservation Strategy or “CWCS” (CTDEP, 2005) identified the Chimney Swift as a species of Greatest Conservation Need in the urban habitat environment. To address the findings of the CWCS, the DEEP embarked on this initiative to more thoroughly assess the Chimney Swift population in Connecticut. 

A Chimney Swift inside the flue of a Chimney in Canada

Chimney swifts are aerial insectivores that are often found coursing the skies over towns, cities, and rivers searching for their invertebrate prey during the spring and summer seasons. Although we do not know the comparative status of these birds during the pre-Colonial period, they were reported by Forbush (1907) in Massachusetts to be “one of the common sights of summer twilight as it flies twittering above trees and houses.” In Connecticut, Sage (1911) reported them to be an abundant summer resident from May until September. Zeranski and Baptist (1990) identified this species as a common migrant, yet an uncommon nester throughout the state in unused chimneys. Clark (1994) speculated that if people continued to screen their chimneys to prevent squirrels, bats, and other animals from entering, Connecticut could experience a marked decline in swift numbers.  

Perhaps this is not the only cause of their decline.  Researchers are investigating historic roosts in hopes of finding other clues concerning the breeding biology and life histories of Chimney Swifts and what may have changed over time. Are there changes in diet, environmental factors, anthropogenic disturbances, pathogens, etc. that have contributed to the decline? The results of one research team in Canada and many more pictures of swifts can be found in the link in the photo caption below. 

Outside of the breeding season, Chimney Swifts often congregate in flocks and often spend the night in communal roosts. Photo Credit: Mike Veltri:

Whatever their past status appears to be, the literature suggests that they were once common breeders in Connecticut but have apparently been declining since the 1960s, and appear to be disappearing from their northern range in Canada. Chimney Swift Watch attempts to address the first step in potential future management decisions by monitoring known sites across the state to assess their relative abundance.  Despite their decline, they are still known for their spectacular twilight aggregations in autumn, when numerous chimney swifts form sizeable flocks before the onset of migration. 

Connecticut Audubon Society’s State of the Birds 2013 addressed the decline of aerial insectivores, so the timing was right for me to volunteer for Chimney Swift Watch.  As a volunteer, I got to choose a roost site to monitor throughout the spring and summer seasons.  I chose the Hartford Armory site for no particular reason except that the name intrigued me.  The First Company Governor’s Foot Guard was organized in October 1771. It is the nation’s oldest continually operating military organization.  You can read more about the history of the First Company Foot Guard here:

The First Governor’s Foot Guard Armory in Hartford hosts a known Chimney Swift roost.  Photo by: Anthony Zemba © Connecticut Audubon Society
The First Company Governor’s Foot Guard Armory is one of over a dozen sites across Connecticut that was selected for the 2013 Monitoring Season. Wildlife biologist Shannon Kearny-McGee of the Connecticut DEEP wanted to know whether the site was used for nesting, roosting, or both. Maggie and I took turns conducting weekly counts to document usage of this site. Beginning in the last week of April, we arrived at the armory twenty minutes before sunset and counted all swifts seen entering, leaving, or flying within 100 meters of the chimney. We recorded temperature, visibility distance in meters, precipitation, cloud coverage, wind speeds, and sunset time. In the beginning of the season (April-May) we had multiple swifts using the chimney, but counts rarely exceeded a dozen birds. By early summer counts remained fairly steady at two individuals throughout most of July and August. Where were the large swirling masses that I had read and heard about entering the chimney at dusk? 

On Monday, July 1, the DEEP organized a swift social event at the Willimantic Brew Pub where we all got to congregate with like swift-minded people involved in the monitoring effort. We dined at the pub’s outdoor tables and drank the pub’s “Flying Cigar Ale” of which portions of each sale went toward swift conservation.  At dusk, we were led on a walk a couple of blocks down Main Street to witness the return of swifts to one of the Willimantic roost locations.  We watched as hundreds of swifts poured into the chimney as darkness approached.  Such had not been the case in Hartford for the Perettos and me since we started monitoring the Hartford site in late April. Shannon thought that perhaps the Armory’s chimney had become a nesting site rather than a roost site. 

The “Flying Cigar” shape of the Chimney Swift in flight.  Notice the spikey feather shafts extending from the tail feathers.  Swifts use these structures to help prop them against the wall of the chimney.
By mid-August, numbers again rose up into the dozen range, but still nothing compared to some of the other sites being monitored in Connecticut.  Early September was not much different until I arrived on site on September 11.  That afternoon, large numbers of swifts began to appear out of seemingly nowhere about 10 minutes before sunset. They organized into a large swirling, twittering mass above the armory.  The swirling mass formed an axis plane that was level with the ground surface but above the rooftop of the armory.  As the flock swirled and gained in number, the axis of the mass shifted and approached the chimney like a giant buzz saw, the teeth of the saw being the outmost individuals in the swirling mass.  As the mass got closer to the chimney, birds began to drop with a flutter into the chimney opening and out of site.  To do this they had to slow their velocity and orient their wings up and back above their bodies and thus only a few could enter at a time – a rate far too slow compared to the revolution speed of the swirling mass, therefore, many birds bypassed the chimney opening and circled back around in time with the majority.  Cycles of swirling swifts continued in this manner until all had their chance to pass by and drop into the opening to settle down for the night. I recorded 132 swifts entering the roost at twilight.  What a spectacle to see.   

The following week, only three swifts entered the roost at dusk, and as I began to write this (the week of September 21) a few reports of stragglers remained in the state.  And so it appears that Chimney Swift migration has come to an end here in Connecticut.  I look forward to seeing what’s in store for 2014, and singing Chim – chim-in-ey again for another summer.

To see how the Hartford roost’s maximum recorded count compared to other sites monitored this year visit the CTDEEP’s project Chimney Swift Watch website via this link: Become a volunteer! 

- Anthony Zemba 
  Certified Ecologist / Soil Scientist
  Director of Conservation Services

A “Flying Cigar” appears over one of Connecticut’s industrial chimneys.  Photo credit: Shannon Kearney, CTDEEP.

Clark, G. Jr. 1994. Chimney Swift In: The Atlas of Breeding Birds of Connecticut. Louis Bevier, ed.  Bulletin No. 113. State Geological and Natural History Survey of Connecticut.  Connecticut Department of Environmental Protection: Hartford, CT.

CTDEP. 2005. Connecticut’s Comprehensive Wildlife Conservation Strategy. Developed by the Connecticut Department of Natural Resources in consultation with Terwilliger Consulting, Inc. October 1, 2005.

Forbush, E. H. 1907. Useful Birds and their Protection. Massachusetts Board of Agriculture. 

Sage, J.H. & L. B. Bishop. 1913. The Birds of Connecticut. Bulletin No. 20 of the State Geological and Natural History Survey of Connecticut.

Zeranski, J. D. & T. R. Baptist. 1990. Connecticut Birds. University Press of New England: Hanover, N.H.

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