Birds
Birds do not have vocal cords but have a structure
at the bottom of the trachea called a syrinx.
Muscles around the syrinx contract to allow vibrations in the walls of
the syrinx when air flows from the lungs, producing sound.
Canada
Geese often call as a flock flies overhead.
The male's sound is a low a-honk, while the female's a higher pitched
a-hink.
During breeding season, a pair may alternate their honks as if the
sound is from a single bird: a-hink-a-honk-a-hink-a-honk.
Sandhill Cranes migrate in large
V-formations, often noisily honking.
Flocks sometimes can be seen circling overhead, gliding on thermals
rising from the concrete jungle below.
American Robins sing a
melodic, cheery carol, often heard at dawn.
Sometimes a bird may pronounce short "peek" and "tut" calls:
When alarmed, it may also give a "whinny" call:
Early American colonists named this bird for its similarity to the
European Robin, which also has a "red breast".
Sometimes the name "Robin" may cause a little cultural confusion, as
in the movie Mary Poppins
"A Spoonful of Sugar"
in the movie Mary Poppins features an American Robin rather than the
European Robin,
though the story takes place in London.
Song Sparrows sing a melodic
tune that begins with three introductory notes, followed by a series
of faster trills.
Here we hear 5 individual variations of this theme.
One representation of the song is "maids, maids, maids, put on your
tea-kettle-ettle-ettle-ettle."
Mourning Dove males begin to
sing in early spring to attract females.
Their sorrowful cooing notes are often mistaken for the hoots of an
owl.
When taking off, their wings can make a whistling sound, or "wing
whistle".
Gray Catbird is another
bird mimic.
It usually does not repeat its phrases, and also has a meow-like call.
Insects
and other arthropods.
Insects do not have lungs or trachea.
Stridulation:
- Crickets and katydids sing by rubbing their forewings together,
vibrating the membranes.
- Some grasshoppers rub a hind leg against a forewing:
Crepitation:
- Band-winged grasshoppers can snap their hindwings when they fly,
making a crackling sound:
Tymbals:
- Cicadas have a pair of "tymbals" in their abdomen.
Muscles in the tymbal pull stiff membranes in a rapid cycle,
creating a buzzing song:
This male True Katydid
sings "katy-did katy-did".
The number of syllables he pronounces is affected by temperature:
- In warmer temperatures, he sings faster and seems to say "Katy did
it, Katy didnt":
- In colder temperatures, he slows down and just says "Katy",
"Kate", or "Did":
Females produce a less strident song:
Snowy Tree Cricket males chirp
to court females.
The chirping rate also varies with temperature; here he is singing at
30°C (86°F).
The chirps slow down at 12°C (54°F):
You can find the temperature in °F by counting the number of chirps in
13 seconds and adding 40.
Snapping Shrimp use their large claw to
produce a sound loud enough to stun prey.
Cavitation occurs when liquid moving at
high speed causes tiny air bubbles in the fluid to form.
The bubbles then collapse, producing a shock wave and the snapping
sound.
Pistol Shrimp
Image: Michel Versluis
Animal Audio Jeopardy
These notes best displayed with Internet Explorer