Pennsylvania Game News - September 2017 - 53

move backward, forward and sideways
because they have more-complex brains.
In most animals and in people, the part of
their brain that responds to visual stimuli
has a back-to-front preference. Hummingbirds have no preference and can move in
any direction.
Their tiny brains can support efﬁcient
movement in three dimensions, which
some scientists believe makes them the
most-complicated of any vertebrate species. During their mating ﬂights, which
we've watched with awe from our
front porch, they make instantaneous
course corrections much faster than a
ﬁghter jet.
Although hummingbirds are not
considered songbirds, biologists Claudio
Mello and Erich Jarvis have found that
hummingbirds, songbirds and parrots
have the same areas in their brains that
control learning and producing songs.
They sing at a higher pitch than songbirds, but their songs are amazingly rich,
and in some species, complex.
Neurobiologists have been comparing birdsong with human speech and
language.
Young birds listen to other birds, and
imitate and practice their songs, seemingly using the same brain structures and
genes as children use to learn language.
Some birds even stutter.
There is incredible variety in birdsong,
as various as the 4,000 songbirds on our
planet.
And if you listen as carefully as Donald
Kroodsma, who has been studying birdsong, especially in the eastern United
States, for more than 40 years, you might
hear the 30 to 40 songs of a Carolina wren,
the 50 to 100 songs of an eastern bluebird,
the 200 to 400 different mimicking songs
SEPTEMBER 2017

and calls of a gray catbird or the 2,000
calls and songs of the mimic-champion
brown thrasher.
Then there is the hermit thrush, the
song of which has been compared to human musical scales, with trills and slides
reminiscent of a woodwind instrument.
Some ornithologists have claimed that
hermit thrushes sing major, minor and
pentatonic scales.
Using recordings of 14 hermit thrushes
from the Borror Laboratory at Ohio State
University, composer Emily Doolittle and
biologist Tecumseh Fitch started analyzing the pitches of 114 song types. When
they slowed them down, they could hear
their harmonies.
"They jumped out at us," said Doolittle,
adding that 70 percent of hermit-thrush
songs were harmonic.
Maybe most miraculous of all are
songbirds that migrate.
Scientists have found they rely ﬁrst
on genetic information for both direction
and distance until they gain experience.
Then they use their own brain maps to
ﬁnd their way.
They build up magnetic maps during
migration. Some also might use odor to
help guide them.
Some researchers even think migrants
might hear the landscape - especially the
ocean - infrasonically to help navigate.
But to do all that, and more, they must
possess fantastic spatial memories.
Every day, it seems, more is being
revealed about the brains of birds.
Researchers recently have found that
the bird that is closest to its dinosaur ancestors is our own wild turkey.
Its chromosomes have had fewer
changes over time than those of other
birds.
And, as any hunter knows, wild turkeys
are wily and smart.
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Pennsylvania Game News - September 2017

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