Bird Song Ecology Terms/Vocabulary
by
Daniel Edelstein, 12 Kingfisher Court, Novato, CA 94949-6826; 415/382-1827
edelstein@earthlink.net,
http://home.earthlink.net/~edelstein/
The Acoustic Structure of Songs and Calls:
Element: A single
sound in the sequence of many sounds of which a song or call is composed.
Note:
Unlike an element, that can be a
harsh or noisy sound, a "note"
is a single sound that is musical in tone-quality
Syllable:
Two or more notes composed together.
Phrase:
Two or more syllables grouped together.
Motif:
A sequence of elements that may be repeated periodically in some
kinds of song.
Syntax:
The specific timing and order of notes, syllables, and phrases in
a song.
Duet
Song: Birds singing in unison (often a paired
male and female) may sing either the same songs
together, different songs, or different
parts of the same song alternately. Sometimes the female finishes the male's
song by uttering a call (e.g., Carolina Wrens, Red-Winged Blackbirds).
(Antiphonal song occurs when the male and female rapidly alternate their
contributions.)
Primary
Song: The "primary song" is the
typical, classic form of a bird’s song.
Secondary
Song: When males are countersinging with one
another, some use a second category of song at dawn/dusk and in highly
aggressive situations (e.g., Black-throated Green Warbler)
Song
Type: The basic structure or pattern of the
song of a species. Song types can be classified in various ways. (Related term:
A Song-variant relates to a species that "varies" from one song type
to another and, therefore, is said to have different forms of songs, or "
song-variants. ")
Subsong:
Heard in young birds, a "subsong" is a random, subdued warbling of
longer duration than primary song; contains only some of the notes typical of
an adults primary song.
Whisper
or Muted Song: Quieter than a primary song, a
"whisper" song is sometimes heard from birds sitting on the nest and
incubating eggs or brooding young. Alarmed male adults(and some females) also
sing "whisper" song, often while hiding in vegetation.
Mimicry:
Birds that may sing their own song, but are also able to copy portions of or
entire songs of other birds are said to be "mimics." Examples:
Starlings, Northern Mockingbirds, Blue Jays.
Song
Dialects: Birds separated by geographic location
retain their basic song forms, but may show slight variation, depending on how
learning and dispersal affect the distribution of vocalizations in a particular
species (e.g., White-crowned Sparrows, Indigo Buntings)
Song
Repertoire: The different kinds or "menu"
of songs uttered by a bird. Some birds sing only one form of song (e.g.,
White-crowned Sparrow) while others may have large repertoire sizes (e.g.,
Marsh Wren, Northern Mockingbird, Brown Thrasher). Repertoire size may vary
widely with geographic location, lifestyle, or age.
Acoustical
Analysis:
Frequency:
A physical measurement indicating the number of vibrations per second of a
sound. (1 vibration per second = 1 Hertz; 1,000 Hertz = 1 kiloHertz)
Pitch:
A song high in pitch has a high frequency (e.g., a yellow or blackpoll warbler)
while a low pitch has a low frequency (e.g., a mourning dove or great-homed
owl).
Intensity:
Is the power of a sound and is expressed in decibels (i.e., A sound that is 10
times more powerful than another has a sound intensity 10 dB higher; if it is
100 times more powerful it has an intensity 20 dB higher, and so on.)
Amplitude:
Is the measure of changes in sound pressure and is related to changes in
intensity. A bird displays great amplitude change when its song varies between
loud and weak sounds (e.g., winter wren)
Loudness: Depends on
the opinion of the listener. Some people may think a sound is loud and others
may feel it is softer. More specific, sounds of equal loudness may be
designated according to decibel levels. For example, we hear as sounds of equal
loudness:
Tone Quality or Timbre: Depends on the physical structure of the sound and this relates to the materials and construction used to make the sound¾whether it’s a bird song, human voice or musical instrument. Pure tones are those of a single frequency, like those heard from a tuning fork or a single note played on a piano. Most birds, however, display complex tones with a mixture of higher and lower pitches (frequencies).
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