Biology Reference
In-Depth Information
Many birds sing a simple staccato trill. When you master the Chipping Sparrow's
song, you can compare similar trills as being shorter (Dark-eyed Junco), slower (Swamp
Sparrow),moremusical(PineWarbler),moremechanical(Worm-eatingWarbler),andso
on. Listening to sound recordings of wild birds will help you recognize those kinds of
differences.
Q How do birds learn their songs?
A
There are almost as many answers to this as there are species of birds! Some scientists
have devoted their careers to figuring this out, species by species.
Some bird songs are hardwired into a bird's brain. Virtually all flycatchers, including
kingbirds and phoebes, fall into this category. If Eastern Phoebes are raised in captivity
and never exposed to their species' songs, they still develop normal phoebe songs.
Marsh Wrens imitate elements of songs they hear. When a Marsh Wren egg was
hatchedandrearedbyHouseWrens,itproducedunrecognizablesongs.Whenexposedto
a training tape, captive Marsh Wrens imitate song elements of a few other species. Wild
malesengagein“matchedcountersinging”withneighbors,sotheycontinuetolearnsong
elements as adults.
Sedge Wrens seem to improvise their own unique song repertoires. American Robins
share some whistles with neighbors, so they apparently learn song elements from one an-
other. Baltimore Orioles may learn their songs from their fathers and neighboring orioles
during their first summer. It's possible to detect differences between songs of yearlings
and older males, so orioles adjust their songs at least until they're two years old.
As beautiful as Hermit Thrush songs are, there has been little study about how they
are learned. Wood Thrush songs have three parts. The middle part is apparently learned
by listening to other Wood Thrushes. The first and last parts are either innate or invented
bythe birds.When WoodThrushes are hand-reared andnever hear their song,the middle
part is slurred. If they're exposed to wild “tutors” after they're a year old, they don't im-
prove this middle part, so there must be a critical time for learning it during their first
year. If hand-reared Wood Thrushes are exposed to tapes with only the middle part of the
song,theyendupsinginganormalsong,withthemiddlepartmatchingthetapedversion.
