Forest Preserve District of Cook County (Illinois)
Nature Bulletin No. 496-A June 2, 1973
Forest Preserve District of Cook County
George W. Dunne, President
Roland F. Eisenbeis, Supt. of Conservation
****:THE BOBOLINK
Most of our songbirds nest and find their food in woodlands, along
woodland borders, or in old orchards. Some, like the robins, house
wrens, martins and bluebirds, usually prefer to live near human
habitations -- even in villages and cities. Others, notably the redwing
blackbird, are found only around marshes and swampy places. But there
is a small group of songbirds which are seen and heard only in open
country: prairies, meadows, hayfields and abandoned farm lands. In
addition to some native sparrows, the horned lark, the killdeer and the
familiar meadow larks, this group includes that happy-go-lucky
"harlequin of the meadows": the Bobolink.
In spring the male bobolink cannot be mistaken for any other bird. Like
the meadow lark and the orioles, he is a member of the blackbird
family. His underparts are black. The back of his head and neck,
however, is buff colored and there are conspicuous white patches on his
shoulders and rump, so that he seems to be wearing "a full dress suit put
on backwards. "
The bobolink's courtship song is an indescribable bubbling melody that
tumbles out faster and faster, pitched higher and higher, with short
variable notes among which "bobolink" can be distinctly heard. It is
often given during flight; also when perched on a bush or clinging to the
top of a tall weed; but never too close to his mate's nest. That harum-
scarum rollicking music baffles the interpreters and imitators of bird
calls although Henry Thoreau caught the spirit of it when he wrote:
"This flashing, tinkling meteor bursts through the expectant meadow
air, leaving a train of tinkling notes behind. "
The female bobolink, a demure olive-green bird with buffy underparts
and stripes on her back and head, looks like a large sparrow. Her nest is
built on the ground in a heavy stand of tall grass, weeds, clover or
similar vegetation, and wonderfully concealed although not roofed over
like that of a meadow lark. The parents never fly directly to it or from
it. They walk. From 4 to 7 bluish-gray or reddish-brown eggs are
camouflaged by being heavily spotted.
Until the young are ready to fly, a family of bobolinks consumes vast
numbers of cutworms, grasshoppers, weevils and other injurious
insects. Later, weed and grass seeds, or grain, are added to their diet.
By that time the male looks like a different bird: he has molted and
wears plumage very much like that of the female and their young. His
call, if any, is merely a metallic "pink".
During the summer, bobolinks gather first in small flocks and by the
end of August have begun a leisurely migration to their winter homes
which may be as far south of the equator as Paraguay or Argentina.
Some flocks may consist of 2000 or more birds and, like robins,
meadow larks, orioles and blackbirds, they migrate mostly in daytime
rather than at night as most songbirds do. There was a time when
hundreds of thousands of bobolinks, called "rice birds ", were
slaughtered annually and sold in markets because of the damage they
did in the rice fields so extensive then in our southern states. Since the
passage of the Federal Migratory Bird Law in 1913, they have been
protected.
Our next bulletin will be issued on September 6. Enjoy your summer.
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