How can we help?

You can also find more resources in our Help Center.

73 terms

Ornithology Exam 2 - Coleman UTTyler

Dr. Coleman's Ornithology Class. UT Tyler
Response to Food Availability
o Track ephemeral food resources
o Responding to annual variations
o Concentrating in local habitats
o Switching food types
Functional response
Ex. They eat more food.
Three types of functional response
Linear, hyperbolic, sigmoidal
Numerical response
Change in population size
Influence of food on spacing patterns
Food is rarely randomly seperated, territory size is larger with low food density, and smaller with high food density.
is useful, and has low risk. Doesn't try anything new or adventurous.
is flexible, but risky. Try's new things, more adventurous. Popular in stable, predictable environments.
Capturing/Handling Food
Basic, tool use, and culture (learned behaviors).
excessive ingestion of food that is typically seen in birds right before migration. Foraging rates can double!
Cached food
stored food, some birds have communal granaries that they store food for their community.
Optimal foraging theory
Energy profit is equal to the difference of the energy gained from the energy cost, dividied by foraging time. Remember the Great Tit example with the conveyor belt,
Bird brains
Account for 2-9% of body mass, and highly misunderstood aspect of birds because they are really intelligent.
form of learning in birds, name says it. Advanced form of learning.
Species with variable food resources...
Species that tend to have variable food sources, are thoguht to be more intelligent as they have learned to utilize more food sources. Intelligence roots in necessity.
Avian nervous system
- Obtain information
- Analyze and repsonse
- Store information
- Coordinate motor impulses
Controls complex behaviors, instincts, and sensory information.
Switching station between Fore/Hind-brain
Includes the cerebellum and medulla, which will integrate muscular control and coordination.
area of the brain where intelligence is developed.
Hippocampal complex
plays most in memory, study on its relationship between brain evolution and social behavior.
these form in birds during certain seasons, but may disintegrate in the upcoming season
formation of new neurons to replace old ones and reallocate brain space appropriately to seasonal efforts.
Three stages of sleep
1) slow-wave sleep (SWF), 2) intermediate sleep, and 3) rapid eye movement sleep (REM).
Cornea and lens
Change curvature while focusing
Cramptons muscles
contractions cause change in the curvature of the cornea and thus amount of refractive light.
contains light receptors that aid in vision
large, black pigmented, pleated and vascularized structure attached to the retina near the optic nerve.
Black and white vision
Color vision
Central fovea
Concave depression which are sites for visual sharpness.
o Raptors can have 6-8 temporal fovea
o Shorebirds have ribbon like strip fovea (horizon)
Flattened eyes
common in Passerines, adapted for quick scanning of large expanses
Globose eyes
common in hawks and raptors, magnifies image, length and width of eye are about equal, which enlarges retinal image.
Tubular eyes
common in owls, adapted for low light levels, long optical axis and huge cornea and pupil serve to increase light gathering ability.
Bird eye lids
Nictating membrane
Visual acuity
ability to discriminate two points as being two points or, in other words, the ability of an observer to resolve fine spatial details. Most birds can resolve up to 100hz.
External ear
Tympanic membrane
Middle ear
columella (stapes)
Inner ear
Round window
Inner ear
where sound is converted into nervous impulses that travel to the brain
Hearing range
1-5 kHz, pretty characteristic of most vertebrates.
Binaural hearing
locate positions of sounds by integrating differences in timing and intensity in left and right hear. Common in owls.
Tactile reception
Equilibrium (balance)
Barometric pressure
HERBST corpuscles
pressure sensitive corpuscles that are onion like layers of which allows for elastic reception and transfer of rapid pressure changes. Abundant in the bill tips of sand pipers and sipes, also woodpeckers. Also located at feather follicles.
The sense of where muscles, feathers, and limbs are in space.
chemical reception like smell. birds have very poor smell. Vulture have enlarged olfactory bulbs, Tube-nose birds have well-developed tubular nostrils that can pick up fish oil and dimethyl sulfide. Honey dues can smell honey.
Whistled songs
Pure or nearly pure sound waves - higher the pitch the higher the frequency of wave oscillation
Harmonic songs
comprised of several frequencies that are multiples of each other, different octaves.
Short notes
good for contact calls
Long high notes
good for alarm calls
low frequency songs
good for long distance and high interference habitats
high frequency songs
good for open habitat with low interference.
formed at the junction of the two bronchi/trachea. Air vibrates the tympaniform membrane
Syringeal muscles
control the details of the syrinz action during song production. Most non passerines have two muscles, while Passerines can have up to 6-8.
Song purpose
Signal potential rivals that a sit is occupied/defended
Advertise to unmated females
Subtle differences
Differences in pitch, syntax, and timing help bird differentiate each other.
Three hypotheses for song repertoire
Sexual selection
Thwart neightbors ability to track movement
Prevent declining interest
Four periods of song development
Critical learning period -> Silent period -> Subsong period -> Song crystallization
Cryptic coloration
inconspicuous coloration that blends in with the background
Disruptive coloration
breaks up the shape and destroys the outline of an object, hindering detection
Pigment is darker dorsall, and is thought to have an adaptive effect of reduciing conspicuous shadow cast on the ventral region
Reverse Countershading
there is darker pigment ventrally opposed to lighter pigment dorsally
Delayed plumage
different plumages as young than as adults. Dull plumage gives the appearance that the bird is in its first year or youth.
Three hypotheses for Rituals
To increase efficiency of communication
To increase clarity of intent
Graded displays
Agnostic behavior
odd behavior where birds foster either hostility or cooperation. Intereactions between partners often start this way.
Sexual dimorphism
the differences between males and females in regards to size and plumage
Annual cycles
birds face seasons of stress and opportunity that correspond to predictable calendar changes in day lenght, climage, and resources.
Cover -> Spring break up and bonding -> Nesting and brooding -> Brooding and late nesting -> fall shuffle.
Bird energy goes to what?
having a periodicity of 1 year, used to regulate timing of molt, breeding, and migration.
The duration of an organism daily exposure to light.
prebasic molt
complete molt
prealternative molt
incomplete molt
argued that predatory birds selectively search for particular cryptic insects.
Russ Greenberg
documented that some birds are reluctant to try new situations when foraging; whereas others are not reluctant.