lab: post midterm

Question 1

what part of the skin are feathers derived from?

Answer 1

epidermal

Question 2

what is the only gland avian skin has and where is it located?

Answer 2

uropygial gland; located at base of tail

Question 3

what does the uropygial gland produce?

Answer 3

oils which are used to waterproof the feathers

Question 4

where are the arrector pili muscles located?

Answer 4

in dermis of smooth muscle; attach to base of feather follicle

Question 5

describe the unlayered dermis of birds

Answer 5

lacks melanocytes; melanin injected directly into developing feather cortex (colour)

Question 6

what are the 2 important parameters of wings which related to flight?

Answer 6

aspect ration

wing load

Question 7

what is aspect ratio?

Answer 7

wing length/wing length
wing length: distance from base of wing to tip of longest primary feather
wing width: distance from leading edge to trailing edge of wing at widest point

Question 8

what is wing loading?

Answer 8

body mass/ total wing area