Final Exam Flashcards
Who were the earliest ornithologist
- Aristotle
- Pliny the Elder
Medieval Beasteries
were books that made myths about birds like the barnacle goose
Old classifications
-water birds vs. land birds
Bird vocalization
Sound is the vibration of air molecules. This works when a band of air is compressed, and then the space formerly occupied is thinned (rarefaction). This process generates
sound waves.
Visualizing bird songs
-sonogram:representation of a sound plotted as a frequency versus seconds
-oscillogram: represents a sound in terms of
loudness versus time.
Physical structure of sound of grouse, owl, doves
low frequency sounds
Physical structure of sound of forest dwelling birds
simple clear whistle to counter revertebrations caused by vegetations
Physical structure of sound of open field birds
broad songs with a rich structure
Calls
Brief sounds with relatively simple
acoustic structure.
-usually genetically determined
-Generally concerned with coordinating the behaviorof the members of the species in a nonsexual way such as flocking, feeding, reactions to predators,migration.
Songs
A series of different notes of different
types so related as to form a recognizable
pattern in time.
-Usually just males vocalize. Primarily under the
control of the male sex hormones and is in general concerned with the reproductive cycle.
-sometimes used in territory defense
Non-vocal songs
- woodpecker drum rolls
- grouse thunder wings
- hummingbird tail feathers
learning to sing can be
- learned
2. inherit
2 kinds of song learners
1.Open-ended: They add new vocalizations to their repertoires throughout their lives. 2.Age limited: They acquire song during a restricted critical or sensitive period at an early age
vocal development stages
1.Critical Learning Period - Also called the Sensitive PeriodEarly time in life when song information is stored for use inlater stages of learning. Lasts less than a year.
2.Silent Period - The time (as long as 8 months) when syllables learned in the previous stage are stored without practice or rehearsal.
3.Subsong Period - The initial practice time which is like infant
babbling.
4.Song Crystallization - The practice period when the young bird transforms syllables from an unstructured repertoire and organizes them into the correct patterns and timing to produce
the song.
Vocal learning birds
- white-crowned sparrows
- Indigo bunting
- chaffinsh
mimicry birds
Northern mockingbird
-Perhaps Mockingbirds use these mimic voices to threaten other species to keep them out of their territories.
Duets
males and females singing together
red winged black bird and california wren
Syrinx
- A unique organ in birds that is the source of
bird vocal abilities. It is almost 100% efficient in
producing sounds, unlike the human larynx that is only 2% efficient
syrinx sound production
sound is produced is by the vibration of
air as it passes through the syringeal passageway
Internal labium –> external labium –> Pressure on the Interclavical Air Sacpushes the Internal
Tympaniform Membrane
Syringeal Nerve Control
Two separate nerves are on either side of the syrinx, so they can be independently controlled.Some birds can duet with themselves and produce two separate sounds simultaneously; one side produces higher pitched sounds while the other the
lower pitch.
Field L
- The main hearing center of the brain.
HVC
Main vocal center. Damage to this results in
birds being mute
LMAN
controls learning of songs
X
Plays a critical role in the crystallization of
song.
RA
This structure excites motor neurons that
control muscles
Neuron system control of song
- Seasonal cycles are important, since hormones control brain size. As day length increases, so does hormone production.This stimulates the Song Control Centers in the brain to sing.
- Song Control Centers shrink during the nonbreeding season when hormone levels are low, and then increase when hormone levels are high.
Genetic based song examples:
- Willow flycatcher
- Eastern Pheobes
Role of song
- Territory defense
- Mate attraction
Functions of songs maybe???
- Great Tits that have a larger song repertoire survive longer than males with smaller repertoire . Perhaps the good health of the larger repertoire males is why this occurs.
- Bewick’s Wren learn more songs if they hatch early in the breeding season than if they hatch late. Early hatching bird have more time to learn songs and probably a better chance to select the better breeding territories.
- Northern Mockingbirds have a larger repertoire the older they get, so this suggests they are healthier and better at surviving
Annual cycles
- reproduction
- molt
- migration
Migration categories
- Permanent Residents - Birds reside in the same general location their entire life.
- Migratory - Birds live in separate geographic areas during different times of the year.
- Nonannual - The basic biological cycle does not follow a 12-month cycle.
Pigeons
- with ample food and a mate they nest until young fledge (or until a mate is lost),
then
2.transition to nonbreeding stage and molt until they have a mate in breeding condition and adequate food for nesting.
Permanent Residents
- typically in tropical regions
- temperate zone permanent resident by temp/ general cycle.
Circadian rhythms
The roughly 24 hour physiological
biological clock.
Pineal Gland is the biological clock in birds. It is located in the top of the brain and has special photosensitive cells that direct the secretion of melatonin, the chemical that regulates daily rhythms with light-dark cycles.
Photoperiod
The physiological reaction of organisms to
the length of day or night.
- Hypothalmus of the brain has special light receptors that monitor day length. These receptors are extremely sensitive to low light intensities that directly penetrate the brain. Neurosecretory cells in the hypothalmus release neurohormones that affects the pituitary gland, which then releases a number of hormones that directly affect the activity of the gonads.
- The reproductive, molt cycle, and migration of birds are all regulated by photoperiod
Non-annual cycles
- Rufous collard sparrow
- Frigatebirds, Crowned Eagles, Griffon Vultures, penguins and Wandering Albatrosses have non annual because they can’t fit their reproductive efforts in one year
Types of migration
- obligate annual migration
- obligate partial migration
- facultative partial migrant
- irruptive
- nomad
