Lecture Exam 2 - Practice Exam

I. Fill-in. Some answers may require a short phrase. (2 pts. each, 60 pts. total)

1.___________________________ Bird hearts are ___% larger than the hearts of similar-sized mammals.

2.___________________________ Function of the crop in birds.

3.___________________________ Dominant region of the forebrain in birds.

4.___________________________ 2 possible mechanisms regulating

5.___________________________ photoperiod sensitivity.

6.___________________________ Hormones regulating growth of gonads.

7.___________________________ The optimal range of hearing in birds is ___ (narrower or wider) than that in mammals.

8.___________________________ The temperature above which birds must elevate metabolic rate to dissipate heat.

9.___________________________ If a bird encounters a type 2 food item (less profitable) when E2/H2 < E1/(S1 + H1), should the bird eat it or ignore it?

10.__________________________ Main nitrogenous waste product in birds.

11.__________________________ Region of cloaca receiving excrement from digestive tract.

12.__________________________ Avian testes may be ___ times larger in the breeding season than in the nonbreeding season.

13.__________________________ Equation describing the rate of heat loss (and heat production assuming body temp. remains constant) from the body.

14.__________________________ 1 reason why maximum metabolic rates during cold exposure are not as high as during flight.

15.__________________________ Function of urohydrosis.

16.___________________________ 2 reasons why birds may not behave as

17.___________________________ if foraging optimally.

18.___________________________ 2 adaptations of avian respiratory system

19.___________________________ allowing very efficient oxygen extraction.

20.__________________________ Functional analogue to mammalian molars in birds.

21.__________________________ Avian structure homologous to C-cells in mammalian thyroid.

22.__________________________ Large birds have a ___ (higher or lower) mass-specific metabolic rate than small birds.

23.__________________________ The optimal time allocation model predicts that a bird should change foraging patches when _________.

24.__________________________ According to the optimal time allocation model, birds should ____ time in the patch if travel time between patches increases.

25.__________________________ Central place foraging predicts that load size should ____ if travel time between the nest and the foraging area decreases.

26.___________________________ 2 active methods for promoting heat

27.___________________________ loss in birds.

28.__________________________ 1 proposed function for pecten.

29.__________________________ Region of oviduct adding shell membranes.

30.__________________________ 1 difference between the syrinx of oscine passerines and those of other birds.

II. Multiple Choice. Choose the best answer. (2 pts. each, 20 pts. total). 1. Which of the following is not true about avian salt glands?
  1. found in pelagic birds,
  2. necessary because avian kidneys can't concentrate salts to very high levels,
  3. secrete solutions up to 25% salt,
  4. involves active transport of ions by Na+ / K+ ATPase,
  5. all of the above are true
2. Normally birds feeding on mature plant matter (including leaves) have a digestive efficiency of 30-40%. Digestive efficiency of leaves is improved to ___ % in the Hoatzin through foregut fermentation by symbiotic bacteria housed in the enlarged muscular crop in these birds.
  1. 52
  2. 61
  3. 71
  4. 84
  5. 97
3. Which of the following does not contribute substantially to cold adaptation in small birds?
  1. a) winter increases in shivering endurance
  2. b) changes in feeding intensity
  3. c) selection of protective microclimates regional hypothermia
  4. e) large winter increases in insulation by feathers and fat
4. Which of the following graphs represents the theoretical relationship between power output (Y axis) and flight speed (X axis) in birds.

5. Which of the following food types is most easily assimilated (i.e., has the highest digestive efficiency)?
  1. nectar
  2. meat
  3. seeds
  4. young plant material
  5. all have similar digestive efficiencies
6. Oxygen consumption is an effective measure of metabolic rate in birds because
  1. all biochemical reactions require oxygen
  2. both the production and breakdown of ATP require oxygen
  3. oxygen is lost from the body both in water and carbon dioxide
  4. the amount of oxygen used to produce a given amount of heat is relatively constant regardless of the substrate being oxidized
  5. all of the above
7. On a theoretical basis, insulation is _____ at the lower critical temperature.
  1. maximized
  2. constant
  3. minimized
  4. modified only by vasoconstriction
  5. unaffected by posture
8. During long-distance migration (supported by burning fat), which of the following hormones is most likely to be secreted at higher levels than in the resting state?
  1. glucagon
  2. insulin
  3. luteinizing hormone
  4. oxytocin
  5. calcitonin
9. Which of the following aortic arches in birds forms the systemic arch that delivers blood to the body?
  1. right 3rd
  2. right 4th
  3. left 3rd
  4. right 5th
  5. 6th
10.Only the left ovary persists in most female birds, but functional right ovaries occur in which of the following families?
  1. Gaviidae
  2. Accipitridae
  3. Alcedinidae
  4. Corvidae
  5. Anatidae
III. Essay. (10 pts. each, 20 pts. total). Use the back of the page if necessary. 1. Describe the adaptations of the sense organs of owls allowing them to function effectively as predators at night.

2. Diagram what happens to metabolic rate and body temperature as environmental temperature decreases during regulated hypothermia and torpor in birds. How and why does this response allow the birds to save energy?