Birds 2 Flashcards
3 points of bird metabolism
high basal metabolic rate (songbirds highest)
rate increases 10x during flight
flight still more energetically efficient than walking same distance
What has a higher metabolic rate, big or small birds?
smaller birds
Why are birds, particularly passerines, more susceptable to dieing of shock?
higher oxygen consumption than most other animals
What are 4 points of birds and air/lungs?
lung tissue is denser and more efficient
one-way flow of air over lungs so always oxygenated (efficiency)
Conchae warm up and clean air on intake and retain moisture on exhalation
air sacs occupy up to 20% of body cavity
What is Conchae?
hollow area on bill that warms and cleans are on intake and retains moisture on exhale
How many chambers are in a bird heart?
4
What are what are 3 features of bird hearts?
largest hearts relative to body size of vertebrates
efficient blood pumping
high blood pressure (subject to heart failure in times of shock)
Describe part one of digestion for birds
enters mouth - horny tongue, few salivary glands
short pharynx
esophagus - long and elastic
Describe part 2 of digestion for birds
crop - storage chamber
stomach - proventriculus has enzymes and connects crop to gizzard where food is ground
Describe a gizzard
muscular chamber lined with rough keratin
contains tiny rocks and grit (purposefully ingested) to grind and mill food
Where are pellets formed and what kinds of birds do this?
formed in proventriculus by owls, hawks and kingfishers out of bones, fur and feathers of prey
Describe part 3 of digestion for birds
duodenum
small intestine
large intestine - has caeca that are sacs or fermentation chambers off the intestine
What is the function of the cloaca in birds?
receives ureters, reabsorbs water (less waste), waste from large intestine, genetal ducts
How is nitrogenous waste excreted?
as uric acid that is excreted into cloaca
excess water is absorbed
forms white paste and mixes w/ feces
How is excess salt excreted?
special salt glands abouve each eye
via internal or external nostrils
water is retained
Describe endothermic
use metabolic heat to maintain a warm, constant, body temp
What are 6 methods of thermoregulation?
Heat production - shivering
Evaporation - gular flutter and panting (2 surfaces, pharynx and cloaca
Feathers - number (varies seasonally) and position (controlled by dermal muscles, sometimes behavioral)
Posture - reduce heat loss (withdraw feet and tuck head under wing) - increase heat loss (extend wings)
Legs and Feet - thermal counter-current, increased blood flow in hot weather
Social behavior - communal roosts, huddling
Describe 5 points of bird vision
dominant sense
colour vision well developed in diurnal birds (many cones)
Nocturnal birds have few cones and many rods
Most see UV
Some see polarized light
What is important about the amount of frequencies birds can differentiate?
mocking
What is important about hearing for hunting owls?
note differences in intensity and timing of sounds btwn 2 ears (placed asymmetrically sometimes) to estimate source of sound (prey)
Why are owl ear openings sometimes symmetrical?
allow them to accurately note differences in the intensity and timing of sounds in both horizontal and vertical directions
What do woodpeckes use their hearing for?
detecting grub below bark and low-frequency sounds preceding earthquakes
What do birds have in place of conspicuos external ear openings?
specialized feathers called auriculars or ear coverts
What is the olfactory sensing of birds like?
poor except in flightless, ducks and vultures
Name 2 conspicuous extinct birds? What was likely cause of extinction?
Dodo and great auk (northern penguin)
easy pickings and hunted to extinction b/c hadn’t adapted to humans as invasive predator
What is special about bird brains?
large and complex with large motor-control areas and optical centers and song control centers
What is intelligence?
ability to learn how to learn, to solve problems and solve future similar problems with increasing speed
What is insight?
ability to envision one’s actions and their consequences
What order of birds has shown remarkable ability to solve problems and use tools?
corvids - crows and ravens
Describe a few cases where birds exhibit great intellectual capacity?
chickadees and nuthatches distinguish empty from full seed husks from weight alone
crows and parrots perform reasoning tests as well as dogs
parrots can learn 1000’s of calls
blue jays learned to avoid toxic butterflies by watching others die from eating them
blue jays locate food better than cats and monkeys
great tits learned to open milk bottles
birds dropping nuts on road for cars to crush
What are 4 modes of communication?
Signal - behavior that alters the behavior of the receiver in a way that benefits the sender
Display - ritualized signal that conveys a specific message
Passive - plumage patterns
Active
What are 3 features of passive communication?
plumage patterns: colours, shape (outline/silhouette), pattern
What can happen if the songs of 2 similar birds are very different?
separation of gene pool from behavioral barrier to mating that results in species differentiation
What are 2 features of active communication?
Courtship displays - visual and vocal
Territorial displays - attract females, detract other males
What are 3 types of sound from birds?
calls, songs, non-vocal sounds
Describe calls
short stereotyped vocalizations, innate
What are 3 types of calls and what are they for?
Alarm - signal danger to other conspecifics
Contact - locate males and young
Flight - keep flock together
Describe songs
complex, often learned (not innate)
territorial
attract females
species identification based on unique
Describe types of non-vocal sounds
stork bill clattering in courtship rituals
mute swans hiss and grunt
woodpeckes peck to defend and attract mates
male grouse beats wings
hummingbirds trill with wings - territorial
What are 2 defining characteristics of migration?
seasonal and predictable, large numbers of individuals
What are 2 types of long-distance non-migration?
Dispersal: movement from natal area, solitary, new location unpredictable, juvenilles leaving
Irruptions: movement away from food-poor areas, not annual, unpredictable
What percentage of N. A. birds migrate?
What percentage of Canadian birds migrate outside of Canadian borders?
75%
90%
What is migratory restlessness controlled by?
hormones activated by changing daylengths
What are flyways?
migratory patterns that birds use
major north south lines
What are 4 major flyways?
East coast, West coast, Rocky mountains, Mississippi river
Why do birds migrate? 3 reasons
when benefits are higher than costs (energy, mortality) of using well separated breeding and wintering areas
food availability is greater in south for winter
higher reproductive success in temperate regions north
Advantage and disadvantage of temperate zone
abundant food and longer days to forage in spring/summer
food shortage in cold winter
Advantage and disadvantage of tropical zone
mild temperatures and food availability in winter
high density of nest parasites and predators in summer
What are 5 major importances of migration?
Flight pattern, time of day, flight mode, lenght of migration, completeness
Name and describe 2 types of flight patterns
Non-stop - over oceans, deserts, mountains (bad weather can cause long term groundings - fallouts)
Hops - 250-300km
Name and describe 2 types of time of day migration features
Diurnal - depends on winds/ updrafts, food resources
Nocturnal - start after sunset, cooler air less turbulent, avoid diurnal predators
Name and describe 2 types of flight mode
Soarers - flight concentrated mid-day when thermals occur (hawks)
Powered flight - often just before dawn (crepuscular), and nocturnal migrants
Name and describe 2 types of length of migration for birds
long-distance - between continents
short-distance - within continents, elevational changes
Name and describe 2 types of completeness for migration
complete - entire population migrates
partial - some individuals over winter on breeding grounds
What are 2 things birds use to migrate?
Orientation - ability to align in an appropriate direction when released into unfamiliar surroundings (internal compass)
Navigation - ability to find a specific geo location from a known starting point
Name and describe 3 features birds use for migration orientation
Sun compass - tell direction from position of sun b/c of internal circadian clock, some birds detect the polarization pattern used on days w/ cloud cover
Star compass - north star gives absolute point of reference
Magnetic compass - can detect the earth’s magnetic field (still under study)
What are 3 main navigational features birds use for migration
Navigational landmarks - coasts, mnts, rivers
Magnetic anomalies
Local landmarks (hummingbirds return to same feeder every year
Name and describe 2 types of dispersal
Natal - 1st movement away from nest area (high mortality)
Breeding - movements of adults btwn breeding locations
What are 4 reproductive features of male birds?
testes small, bean shaped most of time
testes enlarge 300x at breeding season
sperm stored in seminal sack
most males lack a penis (cloaca to cloaca instead)
What are 3 features of the female bird reproductive system?
only 1 ovary and oviduct develop (left side)
egg fertilized at top of oviduct
albumin, shell membrane and shell added during passage down oviduct
What might be one reason female birds have only one ovary?
weight reduction
What are 2 kinds of reproductive monogamy?
Social - male and female cooperate to raise young (may not be genetic father of young) 90% of birds
Genetic monogamy - male and female are sole genetic parents of all the young - rare
What is the difference between social and genetic monogamy?
social may have extra-pair copulations
Why might birds have extra-pair copulations?
females seek because: hedge against infertility w/ primary partner increase genetic diversity of young produce young by higher quality male forced copulations in waterfowl
Why are extra-pair copulations risky for females?
if primary male finds out he may desert female and the nest with already laid eggs or offspring and the female can’t raise them all on her own
How is lack of genetic monogamy detected?
DNA of putative (care-giving) father don’t match young
What could be the reason that the DNA of young and the mother do not match?
nest parasitism - egg dumping by other female intraspecies or interspecies (brown-headed cowbirds don’t care for own young)
What are 4 features of reproductive behavior relating to individually defended territories?
most territories containg food and nest sites
some territories contain only nesting sites
boundaries are dynamic
males defend territory
What are 3 ways male birds defend territory of nests and/or food?
song, visual display, active defense (rarer - behavioral disadvantage if wounded)
What are 4 advantages to colonial breeding?
favored by scarcity of sites safe from predators
favored by scarcity of sites near abundant food
cooperative protection from predators
enhances foraging on ephemeral food supplies
What are 3 disadvantages of colonial breeding?
colony may attract predators
increase spread of nest parasites (lice, mites)
increased competition for food
Describe cooperative breeding
breeders defend group territories
nest helpers of young birds that feed and defend
nest helpers benefit by raising close relatives (kinship selection) and creating large territories for themselves to breed
What are 7 features of reproductive behavior
monogamy
non-monogamous breeding - <3%
brood parasitism
courtship ritual - both sexes participate
What is promiscuity?
no stable social relationship - hummingbirds otherwise rare
What is brood parasitism? what are the 2 types?
females lay eggs in nests of other birds
intraspecific egg dumping parasitism - very common
interspecific parasitism - less common
What are 4 features of polygyny (one male, several females)?
2% of all birds
males provide little to no care of young
young are typically precocial
lekking
What is the difference between altricial and precocial?
altricial hatch undeveloped, blind, naked, helpless (songbirds, hawks, herons)
Precocial - hatch well developed, eyes open, downy feathers (waterbirds, grouse)
What is lekking?
males gather at the lek and display
females choose males; high status males have multiple females
no parental care by males
(sage grouse)
Describe polyandry and the 3 types
one female and several males
1% of all birds
Classic: female lays eggs in separate nests and males incubate and rear
Cooperative: female lays eggs in one nest and several males care for young
Reversed sexual dimorphism: females larger and more colourful
What is polygnandry?
both males and females have multiple mates
rare (smith’s longspur)
What are 4 types of non-monogamous breeding?
promiscuity - no stable social relationship
polygyny - one male, several females
polyandry - one female, several males
polygnandry - both males and females have several mates
What are 2 things included in the courtship ritual of the western grebe?
rushing and weed dancing
What are 6 examples of nesting sites?
trees, cliff ledges, shrubs, crevices, ground, treeholes
What are 8 catagories for identifying birds?
swimmers, aerialists, long-legged waders, small waders, fowl-like, birds of prey, nonpasserine land birds, passerines
How is relative size of a bird identified?
using sizes of common birds as a yardstick
What are 11 features used for field identification?
shape of tail shape of bill shape of wings behavior does it climb trees? How, jerks, down, spiral how does it fly does it swim does it dive? or dip? does it wade field marks - colour patterns relative size
What are some indicators using field markings?
colour patterns tail patterns rump patches eyestripes and eyerings wing bars wing patterns