Biology Reference
In-Depth Information
andfemales“growl”asathreat.Whenmigratingatnight,SongSparrowsalsomakehigh-
pitched
tseep
calls, perhaps to alert nearby birds to their presence in the dark skies.
Paired-up goldfinches make virtually identical flight calls; goldfinches may be able to
distinguish members of various pairs by these calls.
SINGING ON THE WING
Some birds, especially those
that live in expansive grasslands or tundra with few con-
spicuousperches,singinflight.Thisallowstheirvoicetocarryfartherandprovidesthem
with a visual as well as auditory display.
At least one forest bird, the Ovenbird, a warbler living in forests in eastern North
America,alsohasaflightsong,usuallygivenatdawn,dusk,ornighttime.Thebirdstarts
out singing anywhere from ground to mid- or even upper-canopy and suddenly takes off
in labored flight, wings and tail outspread as he circles and continues to sing. This dis-
play has been nicknamed the Ovenbird's “ecstasy flight.” The flight song is quite a bit
different from the normal
teaCHER, tea-CHER, tea-CHER
song produced most of the
day. The function of this song isn't understood yet.
Many male hummingbirds have aerial displays, combining a specific flight pattern,
often a deep U, with a wing buzz. Male Common Nighthawks display by flying toward
the ground and suddenly making a loud boom, produced by air rushing through the
primary flight feathers after suddenly flexing the wings downward during the dive.
Male American Woodcocks may engage in evening “skydances” during the spring.
Several males gather in an open area near the woods where they spent the day. When the
light grows very low, they start producing a buzzy
peent
vocalization from the ground.
Then, one bird will take off, his wings making a lovely chittering sound as he spirals to-
ward the sky. Suddenly he breaks into a chirpy vocalization and drops to the ground to
begin anew. Female woodcocks are drawn in by this display.
