one-note squawks alike— are im-
mediately absorbed, reflected, and
scattered by everything in a bird’s
habitat. Nearby leaves or branches,
canyon walls, and even the wind in-
fluence notes, so over time, species
tailor songs to suit those surround-
ings. Some minimize echoes by
putting more space between notes,
while others use low frequencies
that travel farther. Here’s how some
birds have tweaked their waveforms.
USUAL SUSPECTS
their groove
Fig. 2
Northern cardinal
This seconds-long song often begins
with a loud string of two-part whistles
and ends in a slow trill. Cardinals nest
in dense foliage, but they sing from
lofty perches so their high-pitchedyellowthroat
These marsh-dwellers sometimes re-
peat their short, choppy melodies up to
300 times per hour in the summer. The
explosive sound can bounce through
dense cattails and other tangled vege-
tation at the edges of their native
wetlands. By singing ad nauseam, the
species ensures at least some repeti-
tions reach potential mates’ ears.Canyon wren
This cliff-nester makes a musical ripple
of cascading notes. Although the
melodies bounce and echo off the sur-
rounding canyon walls, the repetitive
nature and slow, descending scale help
female wrens (and human hobbyists)
pinpoint each bird’s location along the
steep rock faces it inhabits.Fig. 1
Wood thrush
This three-part call often consists of
soft, low-pitched phrases flourished
with a final, elaborate trill—a complex
tune compared with other thrushes.
The intricacy makes the tune suscepti-
ble to warping when it hits vegetation,
so males manage by singing from the
lower canopy or midstory of forests,
where there’s less obstruction.
Fig. 6
Black-capped chickadee
Because they often live and feed in
dense, wooded habitats, these cute bits
of fluff can’t always spot other mem-
bers of their flock, even when they’re
close by. The simplicity of their two- or
three-note whistles allows a listener to
judge the song’s quality (and therefore
the singer’s), regardless of any distor-
tion caused by the surrounding forest.Fig. 3
Eastern meadowlark
Amorous males of this species sing from
exposed perches like fence posts or
telephone lines—or while in flight. The
slurred, slightly drooping whistles are
easily heard ringing out through their
native grasslands. In open areas with
few trees to distort their songs, these
birds are free to devise complicated and
variable tunes.Human mnemonic:
cheer-cheer-
purty-purty-purtyHuman mnemonic:
witchety-witchety-
witchety (slow)Human mnemonic:
chk-a-dee-deeHuman mnemonic:
ra-vi-o-li (flutelike)
oo-duh-lay-oh or oodle-drrrrHuman mnemonic:
but-I-DO-love-you
spring-of-the-yearHuman mnemonic:
tewee-tewee-
tewee (slowing)WINTER 2019 • POPSCI.COM by Marion Renault / illustration by AJ FrenaSOURCE:^ MIKE^ WEBSTER,^ CORNELLLAB^ OF^ ORNITHOLOGY20