AD birds Flashcards
Bird vs dinosaur features
Dinosaur features=
Clawed hands (3 fingers)
Teeth
Long bulky tail
Bird-like features= Long spindly legs Long neck Small head with large eyes Pubic bone rotation Fused clavicles > furcula Outwards arm-rotation
Why is the Archaeopteryx important
transitional between feathered dinosaurs and modern birds
Magpie-like body plan
Asymmetric flight feathers
Probably diurnal
The earliest feathered dinosaur with flight-adapted wings…
…but not necessarily the direct ancestor of modern birds!
Describe the Confuciusornithidae
a more “bird-like” early bird
120-125 MYA
Clawed wings
Hollow bones
Toothless beak
Shortened bony tail –”pygostyle”
Sternum (breast-bone)
Describe a microraptor
One of the smallest (adult) dinosaurs
Bird-like, long, thin pelvis
Teeth, wing-claws
Aerodynamic wing+leg feathers
Non-aerodynamic(?) tail feathers
Iridescent black downy body feathers
What are the 3 modern bird lineages?
The Palaeognathae
Large and flightless eg ostrich
The Neoaves
smallest = bee hummingbird
The Galloanserae
What is the structure of a feather
Barb
Barbules with hooks
Vane
Shaft
How do birds care for their feathers
Preening
Preen gland
Bathing
& dust-bathing
Anting
Moulting
Moult reduces flight efficiency, especially in fluttering flight
Why do birds have feathers?
Display= visual + acoustic Flight Camouflage Thermoregulation Insulation
What are the mechanisms of colour production?
Feathers modify the spectrum of reflected light
Pigments – absorb some light wavelengths & reflect others
eg Carotenoids Reflect yellow & red
Describe structural colours = scattering
Very small particles scatter short (blue) wavelengths. Longer (red) wavelengths are absorbed
Create a transparent structure embedded with tiny dense particles
Describe Structural colours = Multilayer Interference
Waves not in phase = destructive interference
Waves in phase = constructive interference
How do birds be homeothermic?
Be very big
Low metabolic rate
Metabolic heat
Thermal inertia
- “Gigantothermy”
Be quite small
High metabolic rate
Metabolic heat
Well insulated
Why is it hard being small and warm-blooded?
Large surface area : body mass ratio
High rate of heat loss
They have a high metabolic rate to replenish body heat
They are well insulated to minimise heat loss
But Good insulation inhibits gaining heat by basking
What are some ways birds can Strategically regulation of body temperature?
Complete homiothermy
40ºC
E.g. red jungle fowl
Strategic hypothermia
0-10ºC
E.g. great tit
Torpor
>10ºC, < 1 day
E.g. hummingbirds
Hibernation
>10ºC»_space; 1 day
Common poorwill
Why fly?
Escaping predators
Catching prey
Foraging, drinking outside home range
Display flights
