birds exam number 2 O_O

Dispersal

one-time movement of young birds away from birth location

Resident

birds reside in one place for their entire life after dispersal

Obligate Migration

Yearly movement of birds between breeding + non-breeding sites

Metabolism

metabolism

BMR (Basal metabolic rate)

measure of birds O2 while at rest (ml O2 per minute)

Nomadic/Facultative migration

Birds move varying lengths different years categorized by variable resources

natal area

place of birth

Partial migration

Individuals in a northern portion of the area migrate while individuals in the southern area do not

Irruptive migration

Irruptive migrants use food that has high variability in its availability and low predictability in its presence in space and time. These birds usually sometimes stay in one place year-round, but in years when food is scarce they may migrate en masse to other areas in search of food during winter.

torpor

extreme hypothermia

2 primary means of communication for birds

visual, vocal

Generating soundwaves

pressure changes in air molecules

cycle

peak-to-peak distance between two sound waves

frequency

#s of cycles per second in sound

Amplitude

“loudness”- determined by change in air pressure associated with sound - more density of molecules = louder sound

three ways that bird song is commonly displayed graphically

spectrogram, oscillogram, and a color spectrogram

spectrogram

displays frequency of sound

oscillogram

displays loudness of sound

color spectrogram

displays both frequency and loudness of sound

ways birds produce sounds without vocalization

specialized feathers (winnowing), bill (drumming), tools

syrinx

bird voice box - positioned close to the lungs and bronchi, as oppose to the humans’ larynx, which is close to the trachea.

biphonation/two-voiced song

syrinx is branched to allow birds to sing 2 songs at once (paired tissues are called labias lol)

side of the syrinx specializes in lower pitch

left side

side of the syrinx specializes in higher pitch

right side

trachea

also helps contribute to song structure, greatly elongated

calls

structurally simple, genetically determined

alarm calls…

make others in the area aware when
a predator is present

songs

the classic vocalizations produced by males
that are used in a reproductive context