Nature
Notes for June 28, 2013
While
doing summer errands in downtown Port Hope, Cobourg, Brighton and probably
several other towns in the area, readers may hear “chittering” from overhead.
If you glance skyward, you will see small birds swirling around, often quite
high up.
The
“chittering” is coming from these birds, Chimney Swifts. They fly swiftly, as
their name would indicate, as they hunt flying insects for food.
The
Chimney Swift is one of four species of swift that occur in Canada and the only
one in eastern North America. Its breeding range in Canada extends from central
Saskatchewan to Nova Scotia. It winters in South America.
The
Peterson field guide describes the shape of this species as “a cigar with wings”.
It has a very short tail with stiff tail feathers to help with balance when it
perches on vertical surfaces. Its wings beat very quickly, but for moments, it
will glide with its wings outstretch in a bow shape.
Although
its feeding habits are similar to swallows, it is not closely related to them.
It has been found to be more closely related to hummingbirds.
Prior
to European settlement in North America, Chimney Swifts made their nests in
hollow trees. European settlers cut most of the eastern forests, but they
provided the swift with another suitable nesting place: many chimneys.
The
nest is built from small twigs cemented to the inside of the chimney wall with
the birds’ special sticky saliva. Usually only one pair of swifts nests in each
chimney.
Northumberland County is rich in Victorian era chimneys. However, many are no longer used and
have been blocked up. Changes in fire codes require that wood burning stoves
and fireplaces now have metal lined chimneys. Many chimneys have been capped to
exclude animals and birds. All of this has reduced breeding places for Chimney
Swifts.
In
the 20 years between Ontario’s two Breeding Bird Atlases, Chimney Swifts declined
46% in the province. While part of this population decline is probably due to
the lack of chimneys, there are probably other contributors to this decline.
Some other factors may include a reduction in flying insect populations due to
pesticide use and drainage of wetlands. These factors may also affect swifts on
the wintering grounds in South America.
In
some places, towers are being erected specifically for this species. The towers
take the place of chimneys and hollow trees.
In
2009, Bird Studies Canada started the Ontario SwiftWatch Monitoring Program.
Through this program, volunteers work with professional biologists to locate
Chimney Swift nesting and roosting habitat.
This
involves finding Chimney Swifts and following them at dusk to try to find out
what chimneys they are using. It also involves trying to count the numbers of
birds using a particular chimney.
This
can be a bit tricky. Although only one pair generally uses one chimney for
nesting, after the nesting period, swifts gather in large flocks prior to
migration. Sometimes, so many are entering a chimney at dusk that it looks as though
smoke is going down the chimney.
For details concerning participation in the SwiftWatch program contact
1-888-448-2473 ext. 124 or OntarioSwiftWatch@birdscanada.org. The web site is www.bsc-eoc.org/research/speciesatrisk/chsw/index.jsp?targetpg=index&lang=EN
There is also a Facebook page for SwiftWatch.
In our area, Colin Griffiths is volunteering on this project. He has
agreed to let me publish his e-mail address. If any readers are aware of
Chimney Swift nests or roosts, contact Colin at griff@ancientbrit.ca.
