Welcome to your second exam. Please read all questions carefully and take your time. If you encounter something you don’t understand, simply ask me for clarification. All questions that require a written response of at least 4 points should be answered in complete, grammatically correct sentences. (Yes, I will mark off for grammatical and spelling errors on those questions.) The exam is worth 100 pts. Good luck!

MULTIPLE CHOICE (2 pts. each) Circle the letter corresponding with best response.

1. Which of the following bones is part of the appendicular skeleton of a ? a) thoracic vertebra b) sternum c) femur d) synsacrum

2. A North American songbird that wears different breeding and non-breeding plumages is captured and banded in January. The bird is most likely wearing which plumage? a) Alternate b) Basic c) Definitive alternate d) Juvenile

3. A young bird that has recently left its nest and still begging for food from its parents is best termed a(n) . . . a) immature. b) fledgling. c) local/juvenile. d) nestling.

4. A warbler becomes “second year” (SY) on the first Jan. 1 after it hatches. When does it cease to be an SY bird? a) After it completes a molt into its definitive basic plumage b) On its literal first birthday c) When it reaches sexual maturity d) When it shows a really obvious molt limit

5. A homeotherm expends energy on thermoregulatory behaviors . . . a) below its upper critical temperature and above its lower critical temperature. b) below its lower critical temperature and below its upper critical temperature. c) above its lower critical temperature and above its upper critical temperature. d) above its upper critical temperature and below its lower critical temperature.

6. Which one of the following is the most accurate term to describe an whose body temperature fluctuates with ambient temperature? a) b) c) homeotherm d) e) None of the above is an accurate term.

7. A Rufous enters on a cold night. Which one or more of the following physiological responses takes place in the bird as it enters torpor in the early evening? a) Heart rate increases to generate heat. b) Body temperature increases to compensate for cold ambient air. c) Body temperature decreases to almost as cold as the ambient air. d) Both (a) and (b) are correct. e) Both (a) and (c) are correct.

7 8. You capture a sparrow in a mist net in October in Oklahoma and suspect it might be HY. Which one of the following provides the best support for your assessment? a) The bird shows a molt limit. b) The rectrices are tapered. c) The bird’s skull is incompletely ossified. d) The iris is dark.

9. Which one of the following is not a name for a specific air sac in ? a) Abdominal b) Anterior thoracic c) Posterior thoracic d) Dorsoventral e) Cervical

10. Doxon et al. (2011) compared samples obtained using a powerful field vacuum (D-vac) and hand- operated sweep nets. Which one of the following statements best describes the main point of their paper? a) D-vac and sweep net sampling provide complementary samples of grassland , with sweep nets capturing significantly larger taxa. b) D-vac and sweep net sampling provide complementary samples of grassland insects, with sweep nets capturing significantly smaller taxa. c) D-vac and sweep net sampling provide redundant samples of grassland insects, so researchers need use only one of the methods. d) D-vac sampling, although more expensive, provided far superior information on the insects sampled.

11. Camber of a bird’s wing is greatest . . . a) at the wing tip. b) close to the body. c) along the leading edge. d) along the trailing edge.

12. To move forward in flight, a bird must generate positive values for which one of the following forces? a) gravity b) lift c) drag d) thrust

13. Assuming a similar physiological response in diving birds and diving , which organ/tissue would you predict to have the greatest blood flow maintained on a long dive in an Emperor ? a) liver b) gonads c) d) pectoralis muscle (for flippers) e) none of the above

14. In birds, chemical breakdown of foods takes place primarily in the . . . a) esophagus b) crop c) proventriculus d) gizzard e) small intestine

15. Compared to mammals, birds use less water in excreting nitrogenous wastes. Why? a) Birds excrete urea, which is soluble in water. b) Birds excrete uric acid, which is not soluble in water. c) All birds have “salt glands” in their heads that use counter-current exchange to concentrate salts in a briney solution that they can expel through the nares. d) Bird kidneys have really long Loops of Henle that are very efficient at concentrating urine.

8 16. Although the nucleated erythrocytes of birds carry less Oxygen than the enucleated erythrocytes of mammals, birds are ultimately better able to deliver Oxygen to their tissues. Which one of the following is NOT a physiological adaptation of birds to help them efficiently deliver Oxygen to their tissues? a) The avian parabronchus contains a system of air and blood capillaries that use a counter- current gas exchange mechanism. b) Avian hearts are about 41% larger than hearts of comparably sized mammals. c) Avian ventricles more completely empty with each contraction, leading to a higher “stroke volume” of blood delivered compared to mammals. d) Avian muscles that rely on aerobic respiration tend to be rich in myoglobin. e) Trick question: All of the above are adaptations that help birds make up for the lower amount of Oxygen that avian erythrocytes carry relative to mammalian erythrocytes.

17. A critically endangered species, the global population of Whooping Cranes fell to 14–15 individuals by 1937. About how many Whooping Cranes were around in Audubon’s day (early 1800s)? a) about 200 b) about 2000 c) about 20,000 d) about 20 million

18. As a result of captive breeding to increase populations and establish new flocks of Whooping Cranes, there are at least three separate populations today. The original flock breeds in Wood Buffalo Park in Alberta and winters at Aransas National Wildlife Refuge on the Texas Coast. There is a non-migratory flock in Louisiana. Finally, there is a population that winters in Florida and migrates north to breed in . . . a) Alabama b) Ontario c) Ohio d) Minnesota e) Wisconsin

SHORT ANSWER and DEFINITIONS (2 pts. each)

19. Areas on a bird’s from which no grow: apteria.

20. Sum total of biochemical processes in an organism: .

21. Globular protein in muscle tissue with a high affinity for binding Oxygen: myoglobin.

22. Slowing force that results from turbulence and friction: drag.

23. Convex shape of an airfoil in cross section: camber.

24. A contrast in color or wear between adjacent feathers of different age: molt limit.

25. Slowing of the heart rate, for example, during the diving reflex of : bradycardia.

26. Tube in the avian lung from which “air capillaries” branch off: parabronchus.

27. (a) If you keep paying attention to the birds in your area, there’s a good bet that in a few weeks you might notice a bird hopping around on a lawn looking for worms just like a robin does. This bird will look just like a robin (because it is one), except that it will have a spotted breast. What’s the name for the plumage this spot- breasted robin is displaying? (2 pts) juvenal plumage

(b) What’s the name for the molt that will transform this robin into its more typical plumage (worn year ‘round) with an unspotted reddish breast. (Be as specific as possible.) (2 pts) 1st pre-basic molt

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28. (a) In the illustration above, what specific molt has occurred to transform the “1st Fall M” plumage into the “1st Spring M”? (2 pts). 1st pre-alternate molt

(b) What’s the most specific name for the plumage worn by the “SPRING ADULT M”? (2pts) definitive alternate plumage

29. Briefly describe two specific advantages of the pigment melanin in feathers.

Melanin is packaged in grnaules of keratin, so a feather rich in melanin is essentially reinforced with an additional amount of the protein that gives feathers their structure, thus making that feather more resistant to wear. Melanin also makes feathers more resistant to colonization by bacteria that degrade feathers.

30. What was the primary objective of the research described in Bayly et al. 2012?

The authors studied Veeries at a migratory stopover location in Colombia. The primary objective was to estimate flight range of energy stored while Veeries temporarily hang out in a stopover site.

SHORT ESSAY (4 pts. each)

31. Describe the source and maintenance of body heat in a poikilothermic ectotherm. Is there any way for such a creature to exist as a homeothermic endotherm? Explain. (4 pts) In a poikilothermic ectotherm, the source of body heat is the external environment (ectotherm) and body temperature fluctuates with the changes in ambient temperature (poikilotherm). A poikilotherm can use behavioral to function as an effective homeotherm (i.e., maintain its body temperature around a narrow range of fluctuation), but it cannot use the metabolic heat it generates to function as an endotherm unless it can insulate its body to prevent heat loss.

32. Briefly describe two forms of evaporative cooling in birds. (4 pts) At least three forms of evaporative cooling we discussed: bathing, gular fluttering, and defecation on legs. All work to draw heat away from the body by raising the energy content of water to the point at which it can change state from a liquid to a gas. With each drop that is converted to water vapor, a drop remains that contains less energy (i.e., is cooler) than the one that just converted. Until that remaining drop reaches a point at which it converts to a gaseous state, it can cool blood in the tissue that is in contact with the liquid. That cooler blood returns to the body to cool down vital tissues.

33. Because camber is lowest near the tips of birds’ wings, the beneficial airfoil shape degrades near wing tips, producing drag. Describe two physical mechanisms in bird wings that help to reduce drag near the tips of birds’ wings. (4 pts) All flying birds possess an alula or “bastard wing” on the 2nd digit that can be extended away from the rest of wing. The three feathers of the alula form a “mini-airfoil” in cross section, promoting the smooth movement of air over the alula’s surface, thereby reducing drag. Some birds, especially large, soaring birds, have a modified shape to their outermost primaries that airflow over the individual feathers. Each outer primary acts as its own mini-airfoil in birds that show this “slotting”. With the individual feather tips acting as airfoils, drag is reduced. Both slotted feathers and the alula reduce the stall speed, i.e., they help the birds maintain lift at slow airspeeds.

10 34. Complete the diagram by labeling the names of the missing structures (4 pts):

Ulna

Coracoid

Pygostyle

Tibiotarsus

35. Interpret the following diagram. (4 pts)

Within taxonomic groups of the terrestrial , smaller species consume more Oxygen per weight than do larger species. Across the full spectrum of comparable body masses, however, birds consume Oxygen at a higher rate than any of the other taxonomic groups. This can be interpreted that birds have the highest metabolism of any terrestrial vertebrates.

36. Interpret the following diagram from Bayly et al. 2012. When (how many days since first capture) would be the optimum time for Veeries to leave the stopover location to begin the next phase of their migration? Explain.

Body mass increased for each day since first capture up until about day 9. After that, increased length of time at the site did not translate to an increased amount of accumulated. Thus, I conclude that 9 days is the optimum length of stay at this stopover location.

11 39. (a) Label the indicated feather tracts on the following figure. (5 pts)

Primary alula coverts

Lesser coverts

Median coverts

Greater

coverts

(b) In the photograph above, a molt limit is clearly evident in two feather groups. Which ones? (2 pts) greater coverts tertials

(c) Based on the evidence presented in the photograph, how old was this bird at the time of death? (2 pts) SY (second year)

38. We listed 10 specific functions of feathers in different birds. List any SIX. (6 pts) •insulation (e.g., nestlings) •crypsis (e.g., owls, nestlings) •flight •species/gender recognition (e.g., sexually dimorphic species like Red-winged Blackbird) •special display (e.g., modified feathers of Club-winged Manakin, Marvelous Spatuletail) •waterproofing (e.g., Common Loon) •display (e.g., general display of health and vigor: pink color of Greater Flamingo) •Gathering food (e.g., rictal bristles) •Gathering water (e.g., modified belly feathers of sandgrouse) •Perch prop (e.g., woodpeckers)

39. List three specific, skeletal synapomorphies that support the case for common ancestry between modern birds and coelurosaurs such as Velociraptor. Then list three specific, skeletal synapomorphies common to modern birds but NOT shared with coelurosaurs such as Velociraptor. (6 pts)

Skeletal synapomorphies between modern birds and Velociraptor: *Secondary palate *3-fingered hand, 4-toed foot *Semi-lunate carpal *Furcula *Bladelike scapula *Hingelike ankle - no lateral movement *Big eyes, big

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Skeletal synapomorphies unique to modern birds: •Loss of teeth •Skull bones fused into a single cranium •Fusion of dorsal vertebrae •6-7 pairs of ribs; support provided by “uncinate processes” •Fusion of lumbar vertebrae, ilium, ischium, and pubis into “synsacrum” •Reduction of caudal vertebrae into short “pygostyle” •Sternum enlarged and featuring greatly expanded keel (“carina”) for muscle attachment •Loss of digits on forelimb – 3 retained, but these further reduced so that only ancient forms and 1 notable modern species with functioning digits. •Coracoid bone enlarged – attaches sternum to shoulder

40. Compared to the erythrocytes of mammals, those of birds are actually less efficient at carrying Oxygen, yet ounce for ounce birds have higher energy demands than mammals and end up being significantly more efficient at delivering Oxygen to their muscles. Describe the specific features of the avian circulatory and respiratory system that allow them to compensate for the fact that their erythrocytes aren’t quite as good at carrying Oxygen as they could be. (6 pts)

Key points to address in a well-constructed essay: • While the erythrocytes of birds confer no advantage in Oxygen-carrying ability relative to those of mammals, birds compensate by being able to readily deliver Oxygen to their tissues. • Respiratory system – describe role of air sacs acting as bellows to create unidirectional flow of air through the lungs, resulting in near 100% oxygenated air flowing through with every breath. • Parabronchi and capillary tubes with cross-current arrangement for efficient gas exchange. • Circulatory system – much advanced to that of with 4-chambered heart; heart larger than other vertebrates’ hearts • Larger stroke volume and high blood pressure of birds • High concentrations of Oxygen-binding myoglobin in muscles.

Total Points: ______(111 possible)

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