MIDTERM EXAM QUESTIONS

MIDTERM EXAM QUESTIONS The following questions are from past AVS 100 midterm exams. A few questions include the answers, most do not. Point values are indicated except for true-false and other obvious short-answer type questions, which are worth 1 point. Essay questions generally ask you to explain, describe or discuss a topic. If you are not sure whether a question requires an essay answer, it probably does not. Often a sentence or two is all that is required to demonstrate your knowledge. (10 pts) Humans and birds have negative impacts on each other. Provide three different specific examples of past (19 th century) negative-human impact on birds due to commercial exploitation and two different specific examples of current negative impacts of birds on humans. (This question does not require an essay answer.) Negative human impacts include: Hunting - Passenger Pigeons, Prairie Chickens Guano collection - destroyed seabird breeding colonies Egging, disrupts breeding - Farallon Islands, Isl. Raza, etc. Feather harvesting - hummingbirds, rheas, egrets Negative bird impacts include: Bird-borne diseases - West Nile virus, salmonella, histoplasmosis, etc. Agricultural pests - Starlings, blackbirds, etc. (20 pts) There are roughly 9,600 species of birds. Define what is meant by species and discuss the mechanisms by which new species arise citing specific examples. (This question requires an essay answer.) (9 pts) What types of information are most useful for determining the relationships between different birds species? Briefly describe 3 different types of most useful information. (10 pts) Why do you think that the processes of evolution resulted in the formation of 9,600 living bird species rather than some larger (say 96,000) or smaller (say 960) number. Provide one line of evidence supporting your reason. (10 pts) At the beginning of the 20 th century, there were 19,000 species of birds. By 1970 the number had fallen to a mere 8,700. Recently it has risen again to about 9,600. Explain. (10 pts) What are the two main assumptions of the biological species concept and how can they be tested? (15 pts) Hawaiian honeycreepers are a classic example of adaptive radiation. Explain. (5 pts) List five structural features shared by birds and reptiles which mammals lack. (5 pts) Upon publication of Darwin s Origin of Species, opponents of evolution argued that if Darwin were correct the fossil record should contain species that were intermediate between, say, birds and reptiles. Several such missing links were subsequently found. Provide the scientific names (genus and species) of two early fossil-bird species and list three ways in which early fossils were intermediate between reptiles and modern birds. (20 pts) Describe chemical and structural bases for birds colors. (full credit answer shown) Colors are found in birds skin, feathers and eggs. Skin colors may result from blood supply (combs and wattles of fowl) or pigments. Egg color is due to two categories of pigments; porphyrins, derived from hemoglobin, which produces brown and olive colors, and cyanin from bile which makes blue and green. Feather colors are either structural or chemical. Structural feathers colors result from interference or scattering. Interference or iridescent colors are produced when different wave lengths of light are reflected and refracted within the barbs and barbules in such a way that certain wave lengths are mutually reinforced or intensified while others are nullified. Often this depends on thin platelets 1

containing air bubbles (Figure 1). Iridescent colors change with the angle of view. Scattering depends upon the scattering of the shorter wave lengths of light by particles smaller than the wave length of red light (Figure 2). Since only short wave lengths will be reflected, these feathers appear blue regardless of the angle of vision. Pigments are of two main types, melanins and lipochromes. Melanins produce black, dull yellow, red and brown. They are non-soluble in organic solvents, and are added to the developing barbs by melanocytes. Lipochromes are soluble in organic solvents, and are of two main types: carotenoids (related to vitamin A) which produce red, yellow, orange and violet; and porphyrin or pyrro) (related to hematin) which produce red, green and brown. Porphyrins are often light-sensitive and fade in sunlight. Some lipochromes also produce blue colors. Finally, the colors of some birds feathers (flamingos, canaries) result from pigments ingested with their food. (10 pts) If you were to make a bird from a muskrat, what 5 structural modifications would you make and why? (5 pts) Compared with the other Zoogeographic Regions, the Nearctic is poor in terms of both number of species and and number of unique families. Explain why. (10 pts) Molt is a conspicuous feature of the lives of birds. Give 2 reasons why birds molt and list 4 proximate causes of molt. (4 pts) With the aid of a diagram, explain how the integrity of a contour feather is maintained. (4 pts) Label the indicated structures (4 pts) Give the names for of taxonomic categories describing the storm petrel Procellariiformes Hydrobatidae Oceanodroma furca (20 pts) Compare and contrast dynamic versus static soaring. Include in your answer: a) differences in behavior, b) wing design, and c) energetics. (10 pts) Glider-pilots flying near the California coast would be well advised to know their birds and chose to fly their craft along with land-soaring birds (e.g. Red-tailed Hawks) rather than dynamic soaring birds (e.g. albatrosses). Explain the value of such a choice in terms of the differences in flight behavior and wing design exemplified by these two birds. (10 pts) Compare and contrast the digestive systems of a fish-eating Sea Eagle and the seed-eating Bornean Jungle fowl. 2

(6 pts) Circle three of the following statements that do not apply to birds that specialize by eating nutrient-dilute fruits, that is, birds which adopt a skimming-strategy. a. Fruit shimmers often have enhanced rates of intestinal glucose uptake. b. Fruit shimmers have relatively simple digestive tracts and short small intestines. c. Often their guts are completely filled with fruit. d. Fruit shimmers have a slow passage time of fruit through the digestive tract to aid digestive efficiency. e. Fruit shimmers have specialized mandibular processes for removing the fruit's exocarp. f. They may only feed for 10% of the day. g. Fruit shimmers produce copious amounts of dilute urine. (6 pts) Because of their attributes, birds are subjects of choice for many fundamental biological investigations. Give three examples of attributes that make birds ideal study subjects. (10 pts) The 14 species of finches currently found on the Galapagos Islands are thought to have evolved from a single ancestral species that colonized the islands perhaps a million years ago. Explain. (2 pts) The Latin name of the Chestnut-sided Warbler Dendroica pensylvanica illustrates what two taxonomic rules? (8 pts) A central problem in systematics is separating characters that are the result of convergent evolution from those shared as a result of common ancestry. Explain. (6 pts) Briefly describe three modern molecular techniques that have revolutionized avian systematics. (6 pts) Describe three ways in which birds can reduce their rate of heat loss at low air temperatures. (6 pts) Describe three ways birds can increase their heat loss at high air temperatures. (10 pts) Explain how birds' wings develop lift and thrust during flapping flight. (4 pts) Briefly explain why there are fewer migratory species in South America than there are in North America. (10 pts) Fill in the blanks. TRADITIONAL HUMPHERY-PARKES EXTENT OF MOLT NATAL DOWN NATAL DOWN Postnatal molt Prejuvenile molt Complete JUVENILE PLUMAGE Post juvenile molt Prebasic molt BASIC PLUMAGE Prenuptial molt Prealternate molt Partial NUPTIAL PLUMAGE ALTERNATE PLUMAGE Prebasic molt WINTER PLUMAGE BASIC PLUMAGE 3

(10 pts) Name the indicated structure and briefly (one sentence max) describe its role in digestion. 1. 2. 3. 4. 5. (6 pts) Describe the type of flight you would expect the species at left to exhibit and explain your reasoning. (6 pts) The bird illustrated at left below weighs 1.0 kg, has a wing span of 2 m, and a wing area of 0.2 m 2. Briefly describe its expected mode of flight and calculate (showing both your calculations and the units) its Aspect ratio = Wing loading = (10 pts) Label the indicated structures. 4

(4 pts) Label the indicated structures. (9 pts) Name three types of feathers, explain where they occur on the bird, and describe the distinctive function that each serves. (6 pts) List six functions of feathers. (5 pts) At the beginning of the 20 th century, ornithologists recognized ca. 19,000 bird species, based on the species concept. Since then, a major change in the species concept has reduced the number of bird species to 9,648. What are species according to the biological species concept? (10 pts) In order to navigate, migrating birds need a compass. Describe evidence that demonstrates the existence of one such compass and briefly describe two other compasses that have been experimentally demonstrated. (6 pts) Describe the type of flight you would expect the species at left to exhibit and explain your reasoning. Answer: Static soaring over land. Broad wings with fairly high aspect ratio and slotted tips are characteristic of land soaring birds. A clade is a set of organisms related by evolutionary descent from a common ancestor (true, false). is the term used to describe the return of migrant birds to the location where they were born. (3 pts) What three pieces of information are required to perform true bicoordinate navigation? (2 pts) What evidence proves that some birds are capable of true bicoordinate navigation. (2 pts) During flight, the wing is lifted partly by air pressure and partly by contraction of the muscle (name the muscle), which inserts on the head of the humerus via a tendon that passes through an opening in the pectoral girdle termed the. The navigational abilities of birds are solely innate, as evidenced by the fact that inexperienced young birds are often no more likely to become lost than adults (true, false). Clock shift experiments demonstrate that homing pigeons can use the sun's position to determine their latitude and longitude (true, false). In most birds, the feathers are arranged in tracts called. The Latin term for the wing flight feathers is. 5

A frigate-bird s feathers weigh more than its skeleton (true, false). What distinguishes a semiplume feathers from a down feather? Species that possess powder down feathers typically lack uropygeal glands (true, false). The winter plumage is lost by the postnuptial molt (true, false). Removal of the thyroid gland would probably decrease or enhance molt (circle one). In the figure at left, the range of air temperatures over which metabolic rate remains constant is termed. Over this temperature range, birds compensate for changes in air temperature by altering their. The lower critical temperature (the temperature below which heat production increases linearly with falling air temperature) is typically higher in small birds than in large ones. In many small finches the lower critical temperature is around 10, 20, 30 o C (chose one). The resting body temperature of most birds is about 38, 40, 42 o C (chose one) and is often o C lower during the rest phase of the daily cycle. Birds of the order (give one order) have a lower body temperatures than most birds. Gular flutter is employed by pelicans and some other nonpasserine birds to increase evaporative water loss at high environmental temperature (true, false). The only bird known to under go prolonged hibernation is the. (2 pts) What is torpor and name a type of bird that exhibits it. (2 pts) Name and describe the well-known ecological principle illustrated by the figure at left. Birds that feed primarily on seeds are termed. The amino acid balance of (a type of food) is so poor relative to that required for growth, that most adults with this diet type feed their young insects. With insect diets, phosphorous, trace minerals and vitamins are often present in adequate amounts, but can be so low that egg-laying females resort to consuming snail shells and bone fragments. Birds with highly restricted diets are termed euryphagous (true, false). More families of birds feed on than any other type of food. Name two ways by which birds minimize interspecific competition for food. Blue feather color is usually due to the pigment cyanocytin (true, false). Fox Sparrows and Common Ringed Plovers are examples of bird species in which the populations that breed farthest north winter farthest south (true, false). In strong fliers like hummingbirds, the flight muscles account for as much as 65% of the total body mass (true, false) (2 pts) During the day, most migrating birds fly at an altitude of 500, 1500, 3500 meters (circle one); at night their altitude increases, decreases, stays the same (circle one). Static soaring, which entails using the velocity gradient in wind above the ocean to provide lift, is used by longwinged seabirds like albatrosses (true, false). All species that belong to the same family are descended from the same common ancestor (true, false). Because the star constellations differ in the northern and southern hemispheres, transequatorial migrants rely solely upon geomagnetic navigation (true, false). A pigeon is time-shifted 6 hours in advance, then released at noon due south of its loft. Which is the mostly likely 6

flight direction it will chose to return to its loft? North, south, east or west (circle one). Zugunruhe is the term given to premigratory fattening (true, false). Populations which differ by 55, 75, 95% (chose one) in their morphological characteristics qualify for designation as subspecies. Many species of North American birds migrate south in fall to spend the winter in the vast forests of the Amazon Basin (true, false). The majority of small birds, including most passerines, migrate at night and rest during the day (true, false). Gwinner s study of European warblers demonstrated that birds are capable of true bicoordinate navigation (true, false). Which of the following was responsible for the extinction of the Audubon s Warbler and Myrtle Warbler, the recent decline of the Golden-winged Warbler, and may threaten the Spotted Owl? a. West Nile virus b. Ornithosis c. Hybridization d. Acid rain Migration is the term applied to the mass movements of birds away from their usual range (true, false). Among congeneric birds, the wings of migratory species are often longer than those of nonmigratory species (true, false). The breeding range (= home range) is where birds breed and spend the greatest portion of the year (true, false). (10 pts) Write the order s number in the blank space. Brown Pelican 1 Penguiniiformes 2 Tinamiformes 3 Rheiformes Bald Eagle 4 Struthioniformes 5 Dinornithiformes 6 Phoenicopteriformes Waved Albatross 7 Podicipediformes 8 Sphenisciformes 9 Anseriformes Chin-strap Penguin 10 Falconiformes 11 Ciconiiformes 12 Casuariiformes Canada Goose 13 Pelecaniformes 14 Procellariiformes 15 Passeriformes Brown Kiwi Darwin s Rhea The order with the largest number of both families and species. The order with relatively few families but many species. The order with the smallest number of both families and species. (5 pts) List five structural features which birds and reptiles share that mammals lack. (4 pts) What are the two main assumptions of the biological species concept and how can they be tested? (4 pts) Over the past 10,000 years, many populations of grassland species such as Burrowing Owls, Thick-knees and Caracaras have gone extinct in the West Indies? Explain why this has occurred in a sentence or two. 7

(10 pts) Place a letter corresponding to one of the above birds in the appropriate blank space. Highest "wing-1oading" (cm 2 /g) greatest lift/unit speed lowest aspect ratio lowest relative profile power fastest f1ier bounding f1ight greatest manuverabi1ity lowest cruising range high-speed wing highest relative power input (P f /P b ) (9 pts) Describe 3 different means by which a totally blind bird could theoretically navigate during migration. (5 pts) Give 5 important advantages birds derive from migration. (2 pts) During the day, most migrating birds fly at an altitude of 500, 1500, 3500 meters (circle one); at night their altitude increases, decreases, stays the same (circle one). Static soaring, which entails using the velocity gradient in wind above the ocean to provide lift, is used by longwinged seabirds like albatrosses (true, false). Aspect ratio is calculated by dividing wing surface area by body weight (true, false). Induced drag is directly related to aspect ratio, so high aspect ratio wings have low power requirements (true, false). is the term used to describe the return of migrant birds to the location where they were born. What three pieces of information are required to perform true bicoordinate navigation? (4 pts) What evidence proves that some birds are capable of true bicoordinate navigation. (2 pts) In a single sentence, explain why larger birds must work relatively harder to fly than small birds. (2 pts). What is "loop migration"? Give an example of a species that does it. (2 pts) Describe in one sentence each, two physiological changes that precede migration. A pigeon is time-shifted 6 hours in advance, then released at noon due south of its loft. Which is the mostly likely flight direction it will chose to return to its loft? North, south, east or west (circle one). Zugunruhe is the term given to premigratory fattening (true, false). (8 pts) Write the name of the Order next to each bird's name (spelling counts!). Lappett-faced Vulture Common Tern Gambel's Quail Chestnut-bellied Sandgrouse Saddle-billed Stork Common Loon Thick-billed Parrot Japanese Crane 8

(6 pts) Of the above possible cladograms, number depicts the most likely evolutionary sequence by which the three species arose. Provide two reasons why this is so. In the name Hylocichla mustelina (Gmelin), the parentheses denote that the species name has changed since it was first described (true, false). Spring and fall migration occur at the same speed, which is faster in larger than small species (true, false). a) (6 pts) Name the numbered parts of the wing in the diagram above. 1. 4. 2. 5. 3. 6. b) (3 pts) What aerodynamic (flight) function is preformed by structures 1, 2, and 5. 1. 2. 5. 9