Early on Sunday morning, Oct 20, a
group of citizen scientists converged on the Knox Preserve to join
Federal bird banders Bob Dewire and Beth Sullivan for a morning
observing the process ornithologists use to study and track
songbirds. The process was new to several observers, but has become
a rite of the Autumn season for several others present.
White Throated Sparrow about to be released after banding. |
Over two decades of banding records
have been compiled for the Knox Preserve where we have studied
mainly the migratory birds. Some are just passing through, others
arriving for the winter, but of course there are several species
that remain year round. During the fall, many species of songbirds
fly south following the visual line of the coast line. Many fly by
night, and at first light, they seek out a welcoming patch of
shrub-land for food, cover and rest. Knox Preserve provides that
oasis along a very densely populated coastline.
On several days during October, at
the peak of migration, mist nets that are seven feet high and forty
feet long are strung up in the pathways through the shrub area of the
preserve. These nets are nearly invisible to the birds as they move
from area to area in search of food. When they encounter the net,
they drop lightly into the mesh pockets and usually remain quite
still.
On Sunday we set up five nets at
dawn. By the time the group arrived, it was time to make our first
rounds of checks. When we approach the nets, it is always a bit like
Christmas, eagerly anticipating the treasures we will encounter. We
have had some wonderful surprises over the years, from Endangered
Species rarities , to hawks and owls. Mostly they are a variety of
songbirds that use this habitat for forage. Birds are gently removed
from the nets and placed in a special box or small bags and then
transported to the station set up with our supplies.
Removing birds from the nets. |
Birds in bags waiting for banding. |
This Sunday morning was quite
successful. In a very short time we captured 26 birds and as all
observers were quite quick to note, almost all of them were the same
species: Myrtle Warblers, otherwise known as Yellow Rumped Warblers
, for the bright yellow patch of feathers on their rump! This is
their peak of migration and the big draw for them at Knox is all the
berries they can find. Many warblers are purely insect eaters and
have had to move farther south as it got colder, but the Yellow Rumps
adapt and thrive on berries, some remaining in CT even over the
winter. They especially love the Bayberry and waxy Cedar berries
that are especially abundant this year.
Yellow Rumped Warbler. |
The banding process itself involves
placing a light weight metal band on the leg of each bird. Each band
has a unique series of numbers, much like our social security number,
which will remain with that bird for its life. If it is caught again,
or found dead, the band number can be reported and traced. A Gray
Catbird, banded here in Stonington was found dead in Guatemala. A
small warbler, an American Redstart, was banded here and only several
days later was re-caught in the Bahamas! Quite the traveler.
Placing the band. |
While we have the bird in hand, it
is an opportunity to measure and record other data about the
individual birds. All this information is dutifully entered into a
USFWS banding database. We determine their gender, when possible, by
looking at plumage and sometimes taking certain wing measurements.
As on a bell curve, the very smallest of a species of songbirds are
often the females, the largest, the males, but there are a lot in the
middle and there is just no way to tell male from female, unless you
are another bird!
Checking plumage on a Yellow Rumped Warbler. |
Measuring the wing chord. |
We weigh the
birds; every little berry counts for these lightweights. We can also
determine if they are the young of this year by checking the skin
beneath their feathers on their head. A young bird’s skull bones
are not fully fused yet, and the skin will show pink. An adult bird
will have full bone cover on their skull and the skin will reveal
white beneath.
Weighing a newly banded bird. |
Each participant was able to hold
and band and do most aspects of the review of these little treasures.
Then they were released to the bushes with just a few chirps and
mutters, to return to foraging, no worse for the experience.
Song Sparrow about fly away. |
In two days this season, we captured
and banded over 100 birds. They included Song Sparrows, a White
Throated Sparrow, a Red Eyed Vireo, a Common Yellow Throat, a Black
Capped Chickadee and over 90 little warblers with the bright yellow
rump!
Written by Beth Sullivan.
Photographed by Rick Newton and Al
Bach.
For more information about the
Federal Bird Banding program visit USFWS Bird Banding Lab's website here.
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