ornithology final

types of vocalization

warning/alarm calls, distress calls, begging calls, flight calls, social cohesion calls, mate attraction songs, territorial songs

frequency

number of complete cycles per unit time completed by an oscillating sound waveform, usually expressed in hertz or kilohertz

pitch

relative positon of a tone in a scale, determined by frequency. high and low frequencies are perceived as high and low pitches

amplitude

loudness/volume/maximum energy content of a sound that is measure in decibles or pascals

filtering

the elimination of some frequency components of a sound by reverberation off of surfaces

glissando

a blending of one tone into the next in a scalelike passage

harmonic

a series of pitches naturally produced simultaneously with a fundamental frequency.

hertz (hz)

unit of frequncy equal to oen cycle per scond

modulation

control of the form of a sound by variation of either frequnecy or amplitude

post-source modulation

contorl of hte composition of a sound after the syrnix by filtering and resonance of the airway

sonogram

visual display of the frequncy content of a sound distributed in relation to time

tone

a sounf of distinct pitch and quality

waveform

the physical energy of a sound wave depicted as a graph of the aur pressure over time

bird SONG

the loud and long vocal displays of territorial or courting birds (men) and are specific, repeating patterns that are pleasing to the human ear. primary compents are notes, syllables, phrases, and trills

bird CALL

short and simple vocalizations used by either gender, includes things like alarm calls, flight calls, feeding calls, nest class, flock calls, etc.

infrasound

low frequency sound that is below the human range of hearing that birds can hear

repertorie

5 to 14 distinct vocalizations of varied acousctucal structures and overlapping functions

flight call function

flight or flight preperation

social call function

seeking companions of unknown whereabouts

injury call function

injured in flight

aggressive call function

fighting, used by captive males only

alarm calls function

danger, esp when used by young birds; escaping a real threat after copulation and moderate danger or after real danger, used by breeding males only;

courtship call functions

active courtship, used by breeding males only; ambivalence toward approach and copulation with a female, breeding males only; ready for copulation, females only

subsong

practice of a real song

song functions

territoriality, identification, and courtship, implication. of social status, pair bonds, and family relationships,

syrinx

the source of avian vocal abilities, operates w/ nearly 100% physical efficiency to create loud, complex sounds and can even produce two independant songs simulataneously

how do birds differ from a mammals vocal box

most other vertebrates vocalize with the larynx and hyoid apparatus, but the avian version of these cant do that

how is sound from birds produced?

the compression of the air column as it passes through the syrnix makes sound

Extrinsic syrnigeal muscles

two pairs of narrow muscles on the sides of the trachea above the syrinx

intrinsic syrginal muscles

originate and are inserted within the syrnix itself

minibreathes

shallow breathes done during long, sustained songs that are sued to breathe and sing simutanesouly

vocal learning ability

the process by which an individual develops a song with acoustic structure that is determined by the songs of other birds in its social environment. the ability can be genetically inherited in passerines

stages of song development

sensory acquisiton phase, where hearing is the most important, and sensorimotor phase, where practice is most important

cirtical learning period

the early period in which information is stored for use in later stages of learning, lasts less than a year

silent period

long period, syllables learned during the early crictical learning period are stored without practice or rehersal

subsong period

practice period without communication, like baby babbling, birdges gap between perceptual and senorimotor stages of vocal learning,

song crystallization

practice period when practice song is transformed into real song by selecting. afew syllables from its unstructed repertorie, perfecting them

auditory template

a genetically inherited cognitive bias to learn sounds with particular species-typical features, screening out sounds it deems irrelevant

how is the central nervous system involve in song learning?

song learning and vocalization requires a lot of brain power, it is the result of three primary neural pathways interacting that connect the nuclei of the brain and the syrnix

stages of nervous sytem in song learning

auditory input pathway brings acoustic info from ears into bran stem via auditory nerves and projetcs them to forebrain —> posterior pathways recives this and produces the nerve impluses that control the syringeal muscles, larynx, and respiration, and regulates song production, then projects it to the anterior pathway —> anterior pathway recieves it, plays a central role in comparing the birds own vocal output with remebered conspefic songs and enables the bird to improve its songs

dialects

birds have dialects and accents, as songs from birds can vary geographically

dialect formation

happens when young males do not learn from their older neighbors with perfect fidelity and the song they make lasts longer than the bird itself

cultural evolution

when vocal traits are passed from one generation ro the next by learning

memes

units of cultural inheritance

vocal mimicry

an opportunity created by vocal learning, when an evolving audiotory template broad or general enough to learn the song of other bird species

duetting

two birds sing a single song that involves simultaneous/coordinated vocal participation by both individuals

honest indicators

indicators that provide objective information about mate quality. repertoire size, learning ability, performance ability, and acoustic structure are thought to be some of them

social behavior in birds

spacing, territorial behavior, social rankings, flocks, social signals

allopreening

when birds in highly social spaces overcome the individual distances to preen each other

territorial behavior

a primary form of aggressive spacing behavior, any behavior designed to maintain an animals exclusive use of an area

why is territorial behavior done?

increased availability of food and foraging area, exclusive access to mates, increased reproductive success, and safety. its very costly energetically, so birds must decide themselves if they want to do it

territory size determination

resource needs, defense costs, predation pressure, and reproductive needs

social rank

is determined by variation in plumage patterns, sizes, voice, and behaviors.

dominance hierarchies

a social ranking among individuals in a group, typically determined through contests such as fighting or other contests of strength or skill.

can be temporary or permenant.

how does dominance hierarchies happen?

when defending a territory is impractical, like the density is high and it is not possible to defend against all of them

types of dominance hierarchies

egalitarian/pecking order— a linear ranking system

despotic—tyrannically/authoritarian/dictatorial

intraspecfic dominace

within the species itself

benefits of being social

dilution effect, fend off predators easier, easier to find mates (leks) and catch prey

dilution effect

the reduced (or diluted) probability of predation to a single animal when it is in a group

leks

the location of an animal aggregation to put on a display to attract the opposite sex

cons of being social

more aggressive, easier to spread disease (!), more conspicuous to predators, more food has to be found and rationed,

benefits of being the dominant one

reproductive success and foraging success

cons of being the dominant one

higher metabolic rates (its a lot of energy), higher stress hormones, danger of being killed by a subordinate

pros of being a subordinate

lower risk of injury from fighting, avoiding stress while having some reproductive benefits

cons of being a subordinate

subject to leader, reduced access to food and shelter/nesting sites

interspecific aggression

impacts the ability of unrelated species to coexist, when different species start to show aggressive and dominant behavior to each other

mimicry

evolutionary convergence in appearance

improves ability of subordinate species to access resources controlled by the dominate species, theorized to be done by sub species to avoid aggression from dom species

flocks

range from loose, temporary aggregations to organized foraging associations of diverse species

benefits of being in a flock

cooperative hunting and feeding, information sharing, safety, increased predator detection

mixed species flocks

flocks made up of several different species, done for reduced predator vigilance and increased foraging efficiency

bird colonies

evolves in response to two environmental conditions: shortage of nesting sites that are safe from predators and/or abundance of clumped or unpredictable food that is distant from safe sites

cons of bird colonies

increased competion for nest sites and mates, increased cuckoldry, stealing nest materials, increased physical interfernace, higher parasite loads, and easier disease transmission, and attract predators with a large gathering of prey

producer-scrounger models

some birds (scroungers) dont look for new food patches and wait for other birds (producers) to find the patches. increases competition at smaller food patches and with the number or scroungers

nuclear species

the beginning species’s of a mixed flock that are highly sensitive to predators, and attract others to the flock and lead the flocks movement

oology

study of eggs

gonads

paired testes in the male and a single ovary in females that are located deep inside the body on the surface of the kidneys

when are bird sexes determined?

at fertilization and its for life, unlike other reptiles they are not hermaphrodites and only contain one sex organ and cannot change that

avian sex chromosones

W and Z

heterogametic

female birds are this, chromosones are ZW

homogametic

male bird have this, chromosones are ZZ

bilateral gynandromorphs

when birds have a testis on one side of the body and an ovary on the other

how does bilateral gynandromorphs happen

following an abnormality in the first mitotic divison of the fertilized ovum, half of a bird embryo becomes female and other half becomes male

sexual differences in bird brains

brain control the hormones secreted by the gonads, estrogen and testorane, which influence sexual distinction in plumage, body size, vocalization, and sexual behavior

medullary tissue

generated by primordial germ cells, becomes the primary tissue of the testes and the secondary tissue of the ovary, older female birds may gain more masculine plumage

cortex

the primary tissue of the ovary

oocytes

the cells that give rise to an ova

what are the processes of the development of a mature ovam into an egg?

1 the formation and deposition of yolk layers 2 the differentitation, growth, and maturation of the germ cell itself

follicular maturation

the period of yolk formation, lasting from 4 - 16 days in different types of birds

central latebra

the center of the yolk, composed of a fluid, white substance called vitellian

infundibulum

the open upper end of the oviduct that actively pulses back and forth toward the ovum so it can take it in

parthenogenesis

the development of unfertilized eggs, VERY rare in birds, only known in domestic birds

primary sex ratio

in poor quality habitats, more females are produced. environmental/other conditions cause the embryo to favor one sex over another

selection of offspring sex

birds can somewhat select the sex of their offspring

ex: female Blue tit birds that get paired with males that have intense ultraviolet coloration produce mostly young males, it is unknown how they do this though

seminiferous tubules

the thick, outer fibrous sheath of the testis encases this dense mass of tiny convulated tubes

avian penis

a special modification of the ventral wall of the cloaca, most birds dont have this it was lost and regained several times in evolution

cloacal kiss

how birds that dont have penis’ mate, males stand on the females back and twists his tail under hers while the female twists into a receptive position, sperm is transferred when each birds cloacal everts

sperm competition

females store sperm in tubules for weeks and may carry different sperm at the same time, leading to competition between males to fertilize the ova the is released from the ovary. last sperm in is 1st one out

its an important part of sexual selection and has led to evolutionary changes in males like large testes, large sperm stores, long sperm, the guarding of mates and frequent sex

how fertilization, egg production, and early development happen

1 respective male (ZZ, testis/penis) + female (WZ, ovary) sex organs —> 2 copulation —> 3 internal fertilization when the ova is released, yolk develops and is 1/3 lipid ¼ protein and water and other compounds all leading to maternal effects

female reproductive tract

contains ovary, infundibulum, magnum (albumin addition coats ovum), isthmus (shell membranes are added here), uterus (shell gland is given pigment), vagina (pigmented egg is expelled), and sperm storage throughout the tract in some species