Pre Midterm Flashcards
Where does the term Ornithology come from?
Ornis = birds
Logos = the study of
What are the two unique characteristics that make a bird a bird
Feathers
Presence of a Right aortic arch that carries pure blood from the heart to the body
What is the consensus on the earliest known “bird” fossil?
Archaeopteryx
Are pterosaurs related to birds?
Not at all, wing structure is completely different
How does the bone structure of Archeopteryx differ from reptiles?
Only by the presence of a furcula -wishbone
What are the two current hypothesis on the origin of birds?
The Theocdont and Theropod hypotheses - theropod is more widely accepted - fact check this w textbook
Two hypotheses on the evolution of flight?
Trees down vs ground up
arboreal hypothesis vs cursorial hypothesis
Provide some common points about the morphology of the common bird
High power breast muscle - 1/2 bw
High body temp 41-45 C
high metabolism
high energy food processing system
light weight skeleton - 4.4%
strong light feathers
balanced body plan - gizzard in center of body
What are the highest and lowest numbers of feathers found in birds?
Swan -25 000
Hummingbird - 940
List 6 functions of feathers
- flight
- streamline body
- conserve body heat
- protection / camouflage
- communication
- radiation sheild???? old???
Why might birds moult?
to replace worn feathers
to reduce parasite load
to change plumage to have different messages for mating or camouflage
Do birds usually moult at the same time
Yes - seasonal / cyclical pattern of moulting
How often do birds moult various parts of their body?
flight feathers are yearly
body feathers are 1-2 times a year usually in summer and sometimes again before breeding
some birds add ornamentation pre breeding but dont fully moult
How many different plumages can birds have and how does that actually work?
birds often have a juvenile plumage, a basic plumage and an alternate plumage
- will cycle through plumage depending on season
- some birds have multiple basic and alternate plumages depending on life stage (?)
When do birds usually not moult?
it is very energetically expensive so birds cannot moult while breeding and while migrating
What is the difference between the majority of eastern birds and the majority of western birds when it comes to moulting?
Most eastern birds breed - moult - migrate to wintering grounds - there is better soils and diet diversity in eastern north America so it they have enough energy after breeding to also moult before moving’
Most western birds breed - migrate south w US - moult - move to wintering grounds - need to move after breeding to staging grounds to refuel and have more energy for moulting as there was not enough to do it all in one shot
Why might birds be colored
Color helps protect against feather wear - pigments are strong
- temperature regulation - dark vs light colored feather
- protection - camo - crypticity
- communication between / among sexes
— may show age or quality of bird towards a mate
— may fool other birds
What are the two things that can cause feathers to be colored?
Biochrome pigment
– melanin
– carotenoids
– porphyrins
Structure
– often blue colors - in the blue jay its transpartent polyhedral cells that scatter blue when reflecting light
– iridescence
How do we get each color on birds?
Melanin - black grey brown
Carotenoids - yellow orange red - obtained from diet . environment (flamingos+ shrimp)
Porphyrins - brown magenta green
Structure based - blue
What are fault bars?
lighter colored feathers in a band across all the tail feathers - indicative of poor feather growth
poor feather growth may be due to lack of nutrients or stress
feathers are brittle and semi transparent
Can there be more than one color on a single feather?
yes
Why might some primarily white birds have black feathers on the tips of their wings
black feathers absorb more heat which produces a slight amount of additional lift
- melanin may also protect from wear slightly
Talk about the range of color vision in birds
birds can see in infared and UV
many species where we thing males look like females are actually dimorphic in UV light
Avian range is 300-700nm
- some gapes are UV - so parents can spot chicks from further away
Do birds sweat?
no
