Birds 1 Flashcards
What order contains half of all bird species?
Passeriformes - perching birds
What is a major distinguishing feature of class aves?
bipedal vertebrates with feathers
- diverse and range from 2g to 100kg
Do all birds fly?
No
- some like the emu, penguin, and kiwi bird have lost this ability
What are 3 types of flight?
explosive - grouse
soaring - albatross
flap continously - hummingbird
Why are bird bills shaped so diversely?
adaptations to specific food sources
- corresponds to diet
What are woodpecker bills adapted for?
drilling and boring for insects
What are toucan bills adapted for?
fruit
What are flamingo bills adapted for?
filter feeding/ mud sifting
- staining/filtering feature of bill
Osprey bills are adaptded for?
fish
What protein are feathers made from?
Keratin
- modified scales
What are the 3 primary adaptive significance of feathers and what is the lesser 4th?
Thermoregulation
Display behavior - colouration, length, shape
Camouflage - opp. of display
Flying last (started for gliding and quick bursts, eventually selected for better and better)
What 3 parts is a feather composed of including the 2 parts of the shaft?
Rachis - Main shaft
Calamus - Quill
Vane - off the shaft
What are the vanes of a feather composed of and how do they work together?
Many barbs that branch into barbules that have hooklets that hook together the barbules in a tight network
What does preening do for feathers?
Re-hooks the hooklets and barbules
Re-zips the feather back together
Why do feathers need to be preened?
makes sure the feather acts as a single unit as air flows over it
What has happened to an ostrich’s feathers?
Lost the interlocking system of barbules and hooklets
- evolution can work backwards
- not selected for anymore, no negative effect of losing feature
What are the 4 main types of feathers?
Flight feathers (primaries - hands, secondaries - forearm, tail)
Contour feathers
Down feathers and semi-plumes
Filoplumes
What is the function of contour feathers?
cover the body for warmth
cover base of major flight feathers
What are 2 features of a contour feather?
may have an aftershaft - plume-like feather at base for extra warmth?
may lack hooklets at base (downy-like)
What is a feature of a down feather/ semiplume feather? What is the purpose?
have barbules but lack hooklets
provide insulation under feathers
What is a filoplume feather and what do they do?
hair or pin feathers
can be found among flight feathers
attached to sensory receptors in skin
When does molting occur?
A certain life stage - juvenille to adult
Seasonal
2 main broad types of molting
Complete - all tracts replaced in a short time
Partial - parts of tracts replaced piecemeal; primaries and/or tail often retained
What is the prebasic molt?
A typically complete molt that results in the basic plumage that occurs for most N.A. birts in late summer/fall
What is the prealternate molt?
A second partial molt resulting in alternate plumage (breeding or camouflage) that occurs in spring prior to mating
What is Eclipse plumage?
Short lived basic plumage during the prebasic molt of male ducks (drakes) that renders them flightless
- drab looking
When do drakes undergo prealternate molt and why?
Undergo in late fall instead of spring to attain breeding plumage and make pair bonds in winter
What is the advantage of colourful plumage for a male duck?
Mate choice outweighs predator attraction
Flight evolved in many different creatures, not just birds. What kind of evolution is this?
Convergent rather than divergent
Aerodynamics: what is lift?
air flowing over an air foil creates lift
both wings and individual feathers act as airfoils
Aerodynamics:what is drag?
reduces lift by slowing air moving over an airfoil (friction/turbulence)
- air doesn’t flow smoothly
What is an airfoil?
structure that creates lift (suction upwards)
both wings and individual feathers act as airfoils
What is an alula and what is the function?
wing slots that direct fast moving air over wing surface to reduce turbulence
What is wing loading?
body/weight unit area of wing
What is high wing loading?
wings small relative to body mass
rapid flapping flyers
What is low wing loading?
Wings large relative to body mass
slow, long flyers, soarers
What is aspect ratio?
ratio of wing lenght to width
What is high aspect ratio?
long narrow wings
- maximum lift and minimum drag, low turbulence
- albatrosses and swallows
What is low aspect ratio?
similar wing length and width
- good control at low speeds, maneuverability (in shrubs and trees)
- many passerines (perchers)
4 main wing types
elliptical
high speed
dynamic soaring
high lift
Describe elliptical wings
High wing load and Low aspect for high maneuverability at low speed, rapid take-off
large wing slots and alulas to reduce drag at low speed
- sparrow, owl, dove
Describe high speed wings
High aspect ratio, high wing load
lack wing slots and alulas
tapered wing tips to reduce drag at high speed
- swallow, hummingbird, falcon
Describe dynamic soaring wings
high aspect (high lift) and low wing load
lack wing slots or alulas
use wind shear above ocean
- albatross, frigate
Describe high lift wings
Low aspect and low wing load
use thermal winds/ updrafts
wing slots and alulas for increasing lift at low speeds
- hawk, eagle, vulture
How are bird bones adapted to reduce weight?
Hollow, often with struts
cross-stabilization so can get even hollower and thinner
many bones are fused, reduced or missing
What is the furcula?
fused clavicles that make the wishbone
What don’t birds have teeth? What do they have in place of teeth?
reduce weight
horny ridges instead and tiny rocks in gizzard that mill food to break it down
Why do birds have such large keel bones on sternum?
to hold flight muscles (similar to bone crest on snake skull that holds jaw muscles)
What are uncinate processes?
bone hooks that join ribs
What is the synsacrum?
pelvis + 3 lumbar and 6 tail vertebrae
What is the pygostyle?
fused tail vertebrae to which tail feathers attach
Why are flight muscles attached to the keel?
convenience and the fact that a low center of mass is important for flight
Why do birds have numerous neck vertebrae?
results in greater neck flexibility
What are red and white muscle fibres for?
red - aerobic activity, sustained flight, walking
white - anaerobic activity, explosive flight
Why do bird feet have so many diverse shapes?
adapted diversity based on lifestyle (walking vs. flying vs. perching vs. swimming vs. prey capture
Describe 4 features of lower limbs and feet
possess bones, tendons, skin, scales
lack muscles
resistant to cold and freezing
locking mechanism when perching and grasping prey
What part of the body do birds walk on?
toes
What are 4 main parts of a bird leg?
knee, ankle, tibia, tarsus
Name and describe 3 types of feet with respect to toes?
Anisodactyl - 3 toes forward, 1 back (passerines, hawks, eagles) Syndactyl - 3rd and 4th does fused (belted kingfisher) Zygodactyl - 2 forward, 2 back (woodpeckers, flickers, nuthatches, parrots)
What are osprey feet adapted for?
long curved talons for catching fish
can be aniso or zygodactyl
spikes on bottom of feet
Why band hummingbirds?
they are important pollinators (warm-blooded - all year)
monitor population increase and decrease
find migration patterns
learn about longevity, physiology, range, fidelity (go back to same places), breeding
