ADVANCED
ORNITHOLOGY
University of Rio Grande
Donald P. Althoff, Ph.D.
Sound Production
& Song – Part I
Reference Chapter 8
LEC
10
Sound Production
There are four basic ways birds can produce sound
• ___________ – through the syrinx
• _____ clipping (think Royal Albatross) and Pecking
(think woodpeckers) using the bill/beak
• __________ (think woodcock with wing feathers
and manakin with wing and tail feathers)
http://vimeo.com/40657519
• _______________ (think prairie chickens and sage
grouse)
Feathers Sound Production
• Manakins
http://vimeo.com/40657519 red-capped manakin
http://vimeo.com/40652880 club-winged manakin
• Woodcock—3 outer primaries
narrower…produce “whistling”
sound in flight
• Prairie Chickens & Sharp-tailed Grouse: as part of
breeding displays “wag” tail that produces some sound
(video clip)
Air Sac Sound Production…with a little help
from the syrinx
• Prairie chickens –
anterior end of
_________ modified as
a vocal sac/resonating
chamber
• Air is forced into the
sac directly from the
trachea via the pharynx
• As sac inflates, sound
waves from syrinx strike
the tense walls acting
as resonators
Vocalizations
• Involve the syrinx
• Two broad distinctions:
A) _____ –associated with _______ territorial males
B) _____ –not associated with breeding
i) distress/alarm calls
ii) flight calls
iii) begging calls
iv) feeding calls
v) nests calls
vi) flock calls
• Technically, there is ___ real dichotomy between songs
and calls in their _______________________________
_____________________________________________
___________ – visual display of the frequency of
a sound distributed in relation to time
Example of two “songs” (top and bottom) of buntings. _________ are
the principal basic units. ______ are 1 or more syllables. Gill Fig 8-2 p217
Range of Vocalizations
• From short clicks of swifts….
• …to quavering whistles of the tropical, partridge-like
tinamous http://www.youtube.com/watch?v=llBEEeBe-P0
• …to the long melodies of wrens
http://www.youtube.com/watch?v=Kbl-mWkSId8
• …to the annoying mockingbird
http://www.youtube.com/watch?v=NNNX3f3_svo
• Range from deep infrasounds to high pitches inaudible
• Range from almost no vocalizations (mute swans, turkey
vultures) to almost unlimited “vocabularies” (mynas,
parrots, mockingbirds)
Modulations within bird songs/calls are
______ among animal sounds
• Modulation—in the form of frequency (pitch) and
amplitude (energy)
• Example—little modulation:
white-throated sparrow
http://www.youtube.com/watch?v=dtZkV_hiiKY
• Example—considerable modulation:
song sparrow
http://www.youtube.com/watch?v=wdaE7eaayKM
Fundamental Dichotomy
• _____________ vs. _____________ songs/calls
• Whistled songs consist of nearly pure (lacking harmonics)
sinusoidal waveforms. Sinusoidal waveforms exist when
with higher pitch, there are more frequent oscillations of
sound waves.
• Harmonic songs have overtones with frequencies that
are multiples of fundamental frequency—the number of
harmonics and their relative amplitude determines
general tonal quality of the notes. One dominant
harmonic has more energy or greater amplitude than do
the others in the spectrum.
Whistled vs. Harmonic Songs/Calls
• Whistled
Blackpoll warbler
http://www.allaboutbirds.org/guide/blackpoll_warbler/sounds
Spruce Grouse
http://www.allaboutbirds.org/guide/spruce_grouse/sounds
• Haromonic
Black-capped chickadee
http://www.allaboutbirds.org/guide/black-capped_chickadee/sounds
Detailed Analysis of the Black-capped Chickadee’s
dee-dee-dee-dee-dee scold call
• Sonogram of one
“dee” phrase
• The number of
“dees” _________ in
relation to the threat
of predation
• Relative amplitude
of the tones of the
harmonic series
Gill Fig 8-4, p219
Number of “dee” notes per call
More on the Black-capped Chickadee’s
“information-loaded” call sharing abilities
Gill Box 8-2, p223
_______________ of sound affects the ease with the
listener—predator or neighbor—can locate its source
• Calls used to locate and/or attract one another
consist of ____________ with broad frequency
ranges…thereby enriching the information about
__________________
• In contrast, alarm calls are _________ (i.e., narrow
frequency range), __________________
____________ that conceal the sender’s
whereabouts.
Eurasian Blackbird
Locate/attract vs. Alarm Call
Call when mobbing an
______
Call to alert that a
_______ is flying over
Sonograms (Gill Fig 8-5, p220)
Physical structure also determines the distance sound
will travel…and how much distortion it will sustain
before reaching its listener
• Interference, absorption, and scattering of sound
waves affected by
a) __________
b) __________
c) __________
• ____________ sounds (like calls of grouse, cuckoos,
doves, and large owls) are most effective for ______
__________ communication
Physical structure…con’t
• Forest-dwelling birds tend to produce simple
sounds
• vs. more complex, frequency modulated songs/calls
are produced by birds in open habitat
• Examples:
rose-breasted grosbeak (forest)
http://www.allaboutbirds.org/guide/rose-breasted_grosbeak/sounds
vs.
grasshopper sparrow (prairie)
http://www.allaboutbirds.org/guide/grasshopper_sparrow/sounds
Other considerations…
• Birds adjust singing behavior to their
surroundings…aka singing environment.
a) hummingbirds sing ______ in the presence of
increased background noise (like a creek)
b) great tits now sing at ________ frequencies
brought on by auto traffic
• Cassowaries—large solitary flightless birds that live
in dense rainforests—use low-frequency sounds (as
do elephants and some whales) to communicate
over long-distance (remember low frequency sound
carries further in a “dense” environment). Achieved
by ‘doubling width of neck’ (aka inflated)
Sound Production by the Syrinx
• Syrinx operates with “nearly 100%” efficiency to
create loud, complex sounds.
• It is a _________…that is unique to birds (note: that
makes three unique features to birds….feathers,
pecten, and now the syrinx)
• It produces sound ________ vocal cords
• It is made of _______ tissues in some species,
________ tissues in some species, or both tracheal
and bronchial tissues.
• Sound is produced by the ____________ of the air
column as air passes through the syringeal
passageway.
Gill Fig 8-6, p224
Gill Fig 8-7, p225
Juncture of
the trachea
and the two
bronchi
Simple (left)
and complex
(right)
syringeal
musculature
1) last free cartilaginous
ring
2) tympanum
3) first group of syringeal
rings
4) pessulus (cartilage)
5) membrana tympaniformis
lateralis
6) membrana tympaniformis
medialis
7) second group of syringeal
rings
8) main bronchus
9) bronchial cartilage
Sound Production by the Syrinx…con’t
• The airways become constricted by the internal and
external __________ (see enlarged handout, top
schematic)
• There is a glass-clear membrane—the internal
typmanium membrane, which with the surrounding
interclavicular air sac gets pushed into the bronchial air
space.
• __________of the labia (internal and external)—not
the tympaniform membranes—determine the basic
characteristics of the sounds produced by the syrinx.
• _________________ control syrinx action during
vocalization. If the bird species lacks these muscles it
can only grunt or hiss.
Sound Production by the Syrinx…con’t
• Most nonpasserine birds
have just ___ pairs of
“extrinsic muscles” either
side of the trachea above
the syrinx
• Most passerine birds
have as many as ___ pairs
of “extrinsic muscles”…
• Thus, “__________” have
more complex
musculature but not
necessarily more complex
vocalizations vs. those
with just 2 pairs.
1
2
3
5
4
5
6
X
Sound Production miscellaneous…
• Some species, like
swans, cranes, some
curassows, and
guineafowl that
produce loud, rich
resonating trumpetlike calls have usually
long trachea that are
________ in the body
cavity or in the bony
sternum itself.