Exam 2 Flashcards
Are birds endothermic or exothermic? Why is this beneficial?
Birds are endothermic (40° C, no matter which environment)
This allows them to be active, fast-moving, and to have endurance
Energetically more expensive, and requires high delivery rates of energy and oxygen to the body’s cells, plus rapid removal of metabolic waste products.
How do birds combat heat loss?
Amount of plumage
Type of plumage (down feathers are primary source of insulation)
Seasonal molts
Positioning of feathers (erector & depressor muscles)
How do birds respond to heat stress? Cold stress?
Shivering
Seasonally upscaling metabolism
Selecting microclimates
Huddling
mechanisms: (1) exposing the bend of the wing, (2) panting, (3) ruffling crown feathers, (4) ruffling back feathers, (5) wetting abdomen periodically, and (6) exposing the legs.
How are bird lungs different from mammal lungs?
Differs in structure and function from mammal respiratory system
Bird lungs are small, compact, spongy structures located among the ribs on either side of the spine in the chest cavity
Lungs weigh as much as similar size mammal lungs but only occupy half the volume
Well-vascularized and light pink in color
Air flows in only one direction, rather than in and out like other vertebrates.
Define the Air sacs
Air Sacs: attached to bronchi and lungs and extend throughout the body cavity to bones.
Define the Nares
Nares: Nostrils
Define the Operculum
Operculum:, protective flap that protects nostrils in some birds.
Define the Conchae
Conchae: Elaborate folds in nasal chamber, increase S.A. over which air flows.
Define the Rete mirabile
Rete Mirabile: network of blood vessels in conchae help control heat loss from body.
What are the two cycles of inspiration and expiration?
Even though airflow is unidirectional, birds still inhale and exhale, but it happens in two cycles of inspiration and expiration.
Cycle 1 of Inspiration and Expiration:
Inhalation one goes down trachea to posterior air sacs rather than lungs
Exhalation one causes that same air to then move into lungs
Cycle 2 of Inspiration and Expiration:
Inhalation 2 moves old, oxygen-depleted air from lungs to anterior air sacs (while simultaneously bringing fresh air into trachea and posterior air sacs)
Exhalation 2 expels CO2 rich air from the anterior air sacs back into atmosphere
What are the four main functions of the circulatory system?
Delivers Oxygen to Body Tissues
Removes Carbon Dioxide for Exhalation
Delivers fuels (glucose and fatty acids)
Removes Toxic Wastes for excretion
How many chambers are in a bird’s heart?
4 chambers
What kind of circulatory system do birds have?
Double Circulatory System
How does the hummingbird resting heart rate compare with medium-sized birds?
Medium-Size Bird Resting Heart Rate: 150-350 bpm (220 avg.)
Hummingbirds >1200 bpm
What do birds use instead of teeth and chewing to break down food?
Birds generally start chemical process FIRST in proventriculus before breaking it down physically in the ventriculus/gizzard.
What is the function of the crop?
The Crop is an expanded esophageal section.
-Stores food
-Softens food
-Regulates flow of food through digestive tract
How many chambers are in a bird’s stomach? What are their functions?
Most stomachs are two-chambered,
made up of proventriculus and gizzard.
Proventriculus secretes acid and peptic enzymes to break down food
Ventriculus/Gizzard further breaks down foods with highly muscular gizzard. Also will store small stones/pebbles swallowed by birds to help break down food
What are the ceca?
The Ceca are small side sacs at the end of the digestive tract.
What is the cloaca used for?
Excretion of Waste (fecal and urinary)
Laying Eggs
Sexual Reproduction
Where does the excretion of water and nitrogenous waste take place?
Kidney and intestines
How is excretion in birds different from that in mammals?
Urine produced by the kidneys mixes with fecal components in lower intestines, where additional water can be resorbed.
Excrete nitrogenous waste in form of white crystallized uric acid.
Why do some birds have salt glands?
glands are widespread among birds subject to salty diets. Large, conspicuous structures located in special depressions in the skull just above the eyes, salt glands enable seabirds to drink seawater and to unload the newly ingested salt rapidly through concentrated salt solutions.
For example, if a gull drank one-tenth of its body weight in seawater, it would excrete 90 percent of the new salt load within three hours (Schmidt-Nielsen 1983). These amazing glands produce and excrete salt solutions that are as much as 5 percent salt, more concentrated than seawater.
albatrosses
What is the third eyelid on birds called?
nictitating membrane that moves horizontally across the surface of the eye.
Birds have a ___________-color visual system of cones. What are they?
4
red, green, blue and uv
What are the purposes of hearing?
Territorial Defense
Mate Choice
Navigation
Prey-finding
What are the three parts of the ear?
External: lack an elaborate external pinnae like mammalian ears, but may have specialized auricular feathers.
Middle: Birds only have one hearing bone, the columnella (stapes), which connects the tympanum (eardrum) to the inner ear.
Inner: pressure-sensitive, fluid system consisting of semicircular canals (organs of balance), and cochlea with hair cells.
What birds have exceptionally good hearing? Are they low/high frequency or both?
Aside from owls, birds don’t have exceptional hearing (hear best between 1-5kHz)
Pigeons, chickens, and guinea fowl can hear low/high frequency sounds extremely well.
Songbirds tend to hear high-frequency sounds better and low-frequency less well
What do the specialized sensory cells in the semicircular canals of the inner ear allow?
Specialized sensory cells in the semicircular canals of inner ear allow excellent sense of balance and body position that is crucial for flight
Sensory hairs at the base of semicircular canals detect movements of statoliths (small, calcium carbonate crystals) floating in fluid. Variation in the pressure of the crystals on hair cells enable birds to sense vertical, horizontal, or rotary acceleration.
What is the importance of the sensory hairs at the base of the semicircular canals?
Sensory hairs at the base of semicircular canals detect movements of statoliths (small, calcium carbonate crystals) floating in fluid. Variation in the pressure of the crystals on hair cells enable birds to sense vertical, horizontal, or rotary acceleration.
What is mechanoreception?
is the perception of physical forces on the body.
What are tactile corpuscles? What do they provide a bird with?
are cells specialized for tactile response and are located at the end of sheather nerve fibers.
Tactile corpuscles provide bird with proprioception, information about the orientation of the body and its parts within space.
What is the Herbst corpuscle?
is largest and most elaborate of tactile corpuscles. They are sensory nerve endings found concentrated in feather follicles (esp. bristle feathers and filoplumes), wing joints, sensitive bill tips, and woodpecker tongues.
How does bird taste and smell compare to mammals?
Birds CAN taste and smell, but to a lesser extent than mammals.
# Taste buds (chemosensory cells):
Chickens: 24
Pigeons: 37
Humans: 10,000
How do brains in birds compare to their body mass?
Birds have big brains relative to their body mass.
What are the three parts of the brain?
Forebrain: behavioral instincts, sensory, learned intelligence
Midbrain: vision, muscular control, physiological controls
Hindbrain (medulla): links spinal cord and peripheral nervous system to major control centers of brain
What does the hippocampal complex control?
Spatial orientation
Cognitive memory
What kinds of birds have exceptional memories? Why is this important?
Seed-caching birds have exceptional memory
Cache thousands of seeds for future use
Corvidae: Crows, Jays, Nutcrackers
Sittidae: Nuthatches
Paridae: Chickadees and Titmice
(Large hippocampus=Extraordinary Spatial Memory)
What is cognition? Why is it important?
Acquisition and processing of information from the environment
Using:
The senses (perception)
Learning
Memory
Decision Making
What traits are typically associated with brain size and cognitive ability?
- Longer incubation
- Cooperative breeding
- Excellent social skills
- Long lived
- Play behavior
What behaviors do crows exhibit when problem-solving?
Reasoning, behavior innovation, Insight learning
Why is vocalization important?
Vocalizations provide species-specific social and sexual signals and function in many aspects of the lives of birds.
What are the two variations that result in diverse birdsong?
Frequency (Pitch) and
Amplitude (Energy or Loudness
What is a waveform? Sonogram?
Waveform: a picture of the sound pressure waves (amplitude/time).
Sonogram: a picture of the different frequency components of the sound over time (kHz/time).
What does a song typically refer to?
Song usually refers to loud, long vocal displays of territorial or courting male birds.
Made up of:
Notes
Syllables
Phrases
Trills
What does a call typically refer to?
Call often connotes short and simple vocalizations, given by either sex
(High-frequency sounds/low-frequency sounds) are most effective for long-distance communication. Circle correct answer.
Low
Differentiate the sounds between forest-dwelling and open-field birds.
Forest-dwelling birds tend to produce simpler sounds, since reverberations off forest vegetation mask/degrade sounds.
Open-field birds tend to produce complex buzzy songs, since simple, sustained tones can be distorted by strong changes in temperature and wind.
What do songs and calls communicate?
Territorial ownership
Attraction of mates
Broadcast of personal characteristics:
Health, sex, age, parring status
Warning of potential dangers
Maintenance of social contact
How does a bird’s signature vary from other birds?
A bird’s signature varies from others in song pitch, phrase structure, composition and syntax.
Syntax is the ordering of notes and phrases.
What is the importance of the syrinx?
Unique vocal organ to birds
Produces loud, complex sounds, including two songs simultaneously.
Y-Shaped, located deep in body cavity behind the heart, near junction of trachea and two primary bronchi (at entrance to lungs).
What is vocal learning?
is the process by which an individual develops a song with acoustic structure that is determined (in part) by the songs of other individuals in its social environment.
Learning guides vocal development in what four main groups?
Learning guides vocal development in four main groups:
Oscine songbirds
Parrots
Hummingbirds
Suboscine bellbirds
Differentiate between open-ended learners and age-limited learners.
“Open-ended” learners like Mockingbirds and other mimids can add new vocalizations to their repertoires throughout their lives.
“Age-limited” learners acquire songs mainly during a critical learning period at an early age.
What are the four stages of age-limited learning? Give a short description for each stage.
Four Stages:
1)Critical learning period
Early period in which information is stored
Usually lasts one year or less:
●White-crowned sparrows 10-50 days
●Male Chaffinches 10-12 months, until testosterone levels rise in spring
●A bird isolated from its model song during this time will never develop a normal song.
●Songs will resemble a “babbling” subsong
2)Silent period
Young bird stores syllables memorized during critical learning period
Can last up to eight months (Swamp Sparrows store syllables for 240 days)
No practice or rehearsal during this period
3)Subsong period
Young bird starts to practice by listening to itself (analogous to infant babbling)
Starts to match vocalizations to memorized syllables
Within +/- month develops into plastic song with rudimentary final structure
4)Song crystallization
Young birds transform plastic song into real song by perfecting syllables and organizing them into correct patterns and timing.
But also will develop “individual signature”
What is an auditory template?
a genetically inherited cognitive bias to learn sounds with particular species-typical features
What are dialects?
Birds that learn their songs exhibit much great geographic variations in song
Is a flycatcher an oscine or suboscine passerine? Circle correct answer.
Suboscine - no learned component
What is vocal mimicry? What birds show vocal mimicry?
Vocal mimicry occurs is a broad auditory template evolves that allows birds to learn the songs of other species (or objects).
Roughly 20% of passerine songbirds practice vocal mimicry.
Most species are “open-ended” learners.
Repertoires of 150+ songs which can change from year-to-year and increase with age.
Common mimics:
Northern Mockingbird
Common Starling
Marsh Wren
Australian lyrebirds
Bowerbirds
Do females sing?
Female song is widespread among birds, especially tropical species with pairs that reside throughout the year in the same territory.
Song can function in territorial defense and mate attraction.
One of most prominent examples of female song behavior is duetting, in which two individuals sing a single song that involves coordinated vocal participation
What vocalizations evolve by natural selection? Sexual selection?
Alarm and begging calls evolve by natural selection.
Songs and Song Repertoires evolve through sexual selection in two ways:
Male-to-male competition
Mate Choice
Male-to-male competition: territorial songs signal to potential rivals that a male is prepared to protect his space and any associated females
Mate choice: Male song is first step toward courtship and pair formation.
●Females respond directly via calls or posturing
Briefly describe the results and importance of the cerulean warbler research.
Best model resulted in an 83 % predictability rate of male pairing status
-Unpaired males had significantly higher song rates than paired males
-Unpaired males’ songs were significantly higher in frequency than paired males’ songs
Results
-Unpaired males had significantly higher song rates than paired males
-Unpaired males’ songs were significantly higher in frequency than paired males’ songs
-Increased song rates and higher frequencies in unpaired male Cerulean Warblers are comparable to that of other wood warbler species
What is the circadian rhythm?
physiological clocks that control avian annual calendars by synchronizing a bird’s internal state with its seasonal environment
What types of changes in behavior are triggered by shortening or lengthening photoperiods?
Breeding,
Migration
Foraging
Molting
Amount of rest
What does a bird need to be in breeding mode?
Food and mate
What is Zugenruhe? Do non-migratory birds exhibit this? Is it affected by sex hormones?
migratory restlessness
No
No
How does day length affect Zugunruhe?
Increasing (Spring) or shortening (Fall) day length stimulates restlessness, hyperphagia, fat deposition, and weight increase.
Extrinsic weather also plays a role:
●Warming temperatures in higher latitudes=Northward movements of migrants in spring
●Other factors affecting migration include: daily weather, lowering of barometric pressure creating favorable tailwinds.
What is migration? What is an example of local vs long-distance migration?
a predictable, cyclic behavior that takes advantage of predictable, seasonal opportunities such as climate and food availability.
NOT the same as nomadic wandering or irruptions tied to unpredictable, aseasonal opportunities (e.g Red Crossbills attracted to insect infestation, and then will breed where food is abundant).
Local: Tropical Hummingbirds migrating up and down mountain slopes at different times of year
Long-Distance: Bar-tailed Godwits migrating non-stop from Alaska to New Zealand
What are flyways?
are routes that follow topographies of coasts, mountain ranges, major river valleys, and deserts.
What is radar? How can it be used to track bird migration?
Radar:
A system that sends out radio waves that reflect off of objects. This allows detection of aircraft, precipitation, missiles,etc.
Radar Ornithology:
Radar beams also bounce off of birds, bats, and insects.
Military-grade Doppler can detect an individual bird, so total numbers of migrants in the night sky can be determined.
What conditions are required for successful migration?
Must fly at times of day and at heights that are:
-Least costly
-Safest
-Most Rapid
Usually choose altitudes below 800 meters, but waterfowl have been spotted @ 9,000 m.
Fallouts occur when 1000’s of birds land after crossing large bodies of water, deserts, or encounter headwinds.
(Examples: Texas and Louisiana coasts after crossing Gulf of Mexico)
Depending on species, migration can be by day, night, or both.
What are advantages to diurnal migration? Nocturnal?
What are the benefits and costs of migration?
Benefits:
Predictable climates
Predictable food sources
Large expanses of temperate-zone habitats for low-density breeding (thus reduced predation)
Use of less energy in winter
Costs:
Weather events
Building/Structure/Window Collisions
Possible habitat loss
Global Transmission of Diseases to other birds, livestock, humans (Avian Influenza, West Nile Virus)
What is important about stopover sights?
High quality stopover sites with plenty of food are critical for successful migration.
Songbirds typically fly several hundred km overnight and then pause for 1-3 days of rest and refueling.
Most Arctic shorebirds have 3-4 strategic stopovers, from N. America to tip of S. America
Preserving habitat is critical for successful migrations.
Important Bird Areas are a worldwide network of protected stopover sites found in >200 countries
What are the four ways that birds navigate? Briefly describe each.
-Visual Landmarks
Pigeons routinely follow highways, railways, rivers even if not the most direct route home.
Ducks will follow coastlines but are reluctant to cross large bodies of water unless they have tailwinds.
Thus, coasts and corridors can act as funnels, since birds are reluctant to cross large bodies of water or desert without tailwinds.
-Sun/Stars
On sunny days, Common Starlings housed in circular cages (with the sun visible) focused their attention toward the northeast, the correct direction for spring migration.
On cloudy days, the starlings showed no directional tendency.
Indigo Buntings are a North American, night-time migrant (Eastern U.S. to Central America).
In a state of Zugunruhe, buntings were placed in a circular cage under a planetarium night sky.
The buntings oriented themselves ______ under a simulated spring night sky.
…and _____ under a simulated winter night sky.
-Olfactory Cues
Pigeons seem able to detect trace gases in atmosphere.
Volatile hydrocarbon compounds are resistant to wind disruption and thus provide reliable sources of information, especially in urban environments.
Young pigeons screened from prevailing winds and odors don’t navigate as well as those exposed.
-Earth’s Magnetic Field
A 1974 experiment showed pigeons DO use magnetic fields for orientation, especially on cloudy days.
Pigeons fitted with disruptive magnets could not orient properly on cloudy days.
How does Geomagnetism Work?
-Specialized photopigments called Cryptochromes in birds retinas are sensitive to magnetic direction.
-Cells in hippocampus and neurons in brain stem are sensitive to magnetism.
-Inner ear also contains magnetic iron compounds.
What parts of a bird’s head are sensitive to magnetic direction/magnetism?
Specialized photopigments called Cryptochromes in birds retinas are sensitive to magnetic direction.
-Cells in hippocampus and neurons in brain stem are sensitive to magnetism.
-Inner ear also contains magnetic iron compounds.
Are navigational abilities learned, innate, or both?
Both
nexperienced, young migrant birds become lost more often than experienced adults.
Most global navigation by young birds is done with adult in the lead.
Axis rotation of stars is more important for (diurnal/nocturnal), (long-distance/short-distance) migrants. Circle correct answer.
Nocturnal, long-distance
What is the Krushinsky Problem?
Many birds out perform many mammals cognitively
Bird brains are constructed differently than mammalian brains, but still enable higher cognitive abilities.
Many birds have more pallial neurons in their forebrains than primates with brains 3x the size
Through intelligence tests, birds have exhibited:
Object memory and mental time travel
Delay of gratification
Reasoning
Insight Learning
Behavioral Innovation
Repertoire
The full range of sound it makes typically 5-14 in most birds
