Deck 12: Foraging Behavior

Question 1

Suspension feeding generally refers to

A) aquatic species removing small suspended food particles from the surrounding water.
B) arboreal species feeding on fruit while they are suspended from branches.
C) the feeding that some species do just prior to going into hibernation.
D) various spiders feeding while suspended from silk strands that they have spun.

Answer 1

aquatic species removing small suspended food particles from the surrounding water.

Question 2

Suspension feeders are

A) large.
B) sessile.
C) small.
D) may have any of the above characteristics.

Answer 2

may have any of the above characteristics.

Question 3

A limitation in the availability of a preferred food, a need for nutritional variety, or a need to minimize exposure to risks associated with a particular predator or with a particular toxin may lead to

A) carnivory.
B) herbivory.
C) omnivory.
D) suspension feeding.

Answer 3

omnivory.

Question 4

A plant may need to develop defenses to keep animals away from its

A) fruit.
B) pollen.
C) roots.
D) seeds.

Question 5

Milkweed beetles (Tetraopes tetrophthalmus) bite repeatedly into the midribs of the milkweed plant's leaves. This behavior

A) allows them to feed from the highly nutritious sap contained in the leaves, which can be harvested in no other way.
B) allows them to feed from the tips of the leaves without being bothered by the noxious chemicals in the sap.
C) attracts other beetles, which provides an opportunity for a male to court a larger number of females simultaneously than would otherwise be possible.
D) causes the plant to die, which eventually eliminates a potentially dangerous plant from the beetles' environment.

Question 6

A special type of fungus, known to exist only in special fungus gardens, is actively cultivated by

A) baleen whales.
B) bolas spiders.
C) leaf cutter ants.
D) lowland gorillas.

Question 7

Cheetahs, Northern gannets, and dragonflies are similar in that they each obtain their prey by means of

A) aggressive mimicry.
B) pursuit.
C) setting traps.
D) stealth.

Question 8

Aggressive mimicry can involve a predator mimicking

A) attention getting, food-like objects.
B) the appearance and the behavior of a beneficial species.
C) the courtship signals of the prey species.
D) all of the above.

Question 9

A species that is very sensitive to the vibrations transmitted by its prey through the sand is the

A) platypus.
B) rattlesnake.
C) scorpion.
D) star-nosed mole.

Question 10

Seabirds such as petrels and albatrosses detect their prey in the ocean by means of

A) electroreceptors.
B) sight.
C) smell.
D) all of the above.

Question 11

The pores near the mouths of sharks, which lead to gel-filled tubes in the sharks' heads, allow a shark to locate prey by detecting

A) electrical fields.
B) olfactory cues.
C) visual information.
D) weak disturbances in the water.

Question 12

When Tinbergen (1960) was observing birds bringing insects to their chicks, he noticed that they took insects in unexpected proportions.

A) The birds always took the same number of each species, even as the species' relative numbers changed over the season.
B) The birds captured the different species in proportion to their abundance as the season progressed.
C) When a species became more common, it was taken more frequently than would be expected.
D) When a species was low in numbers, it was taken more frequently than would be expected.

Question 13

A heightened ability to detect a target has been called forming a(n)

A) optimization guide.
B) overselection bias.
C) search image.
D) target species.

Question 14

Pietrevicz and Kamil (1979, 1981) simulated predator-prey interactions in a laboratory between blue jays and moths. They found that the jays' ability to detect cryptic prey improved

A) as increasing numbers of different moth species were shown.
B) when the target species was low in frequency.
C) when two different species were presented in random order.
D) with consecutive encounters with a single species of prey.

Question 15

What to eat, where to look for food, how long to search, and what path to take are examples of ideas that are useful to optimality theory because they

A) are activities about which animals are capable of performing conscious decisions as they work out cost-benefit ratios.
B) ensure that there are always some benefits available to be measured.
C) help us break foraging behavior into a series of decisions that can be focused on one at a time.
D) provide a common currency for analysis.

Question 16

Rate of energy gain is a "common currency" that is frequently used as an indicator of beneficial long-term fitness effects. We usually feel comfortable with that because

A) increased food intake has been found to increase survival and fecundity in a number of species.
B) it can be measured over varying units of time.
C) it can usually be measured directly.
D) all of the above

Question 17

In general, mathematical models

A) rarely allow accurate predictions.
B) tend to accurately reflect natural complexities.
C) tend to generate a picture of nature that is overly complex.
D) tend to oversimplify nature.

Question 18

A food item's "handling time" would best be considered a(n)

A) constraint in a model.
B) negligible variable.
C) portion of the search time.
D) type of common currency.

Question 19

If the following equation (where E=energy gained, h=handling time, and S=search time) is an accurate representation of the rate of return for two prey types, which one (prey type 1 or prey type 2) should the individual eat?
$\underline{E_1} > \underline{E_2}\\H_1~~~S_2+h_2$

A) Prey type 1
B) Prey type 2
C) Either prey type 1 or 2; their rates of energy gain are essentially equivalent.
D) Neither; they both will inevitably require more energy to consume than they will provide.

Question 20

In field tests of optimal diet theory, it is impossible to control the rate at which the subject encounters prey types. When tested in a laboratory with appropriate controls, however, Krebs and his coworkers (1977) found that when large mealworms were made more plentiful, in contrast to the model's predictions, his bird subjects

A) consumed small and large prey in direct proportion to their presentation rates.
B) immediately excluded smaller prey from their diet.
C) never completely excluded smaller prey from their diet.
D) tended to exclude large prey items from their diet.

Question 21

Sih and Christensen (2001) reviewed 134 studies to examine the success of optimal diet theory. They found that

A) the model did a good job of explaining diets of foragers that consume prey that are immobile or essentially immobile.
B) the model performed best at predicting diets of foragers when the prey items were active.
C) the model performed better when predicting the diets of mammals than it did that of birds or fish.
D) there was a great deal of agreement from one study to the next in terms of the performance success of the model.

Question 22

Regardless of the cause, at some point it will become advantageous for a forager to move from a currently used patch to a new one, where food may be easier to find. In 1976, Charnov modeled this problem in the

A) cost-benefit ratio.
B) energy maximization theorem.
C) marginal value theorem.
D) optimal patch theorem.

Question 23

Combining information about the cumulative amount of energy that a forager is gaining as it remains in a patch with information about, for example, the travel time to the next patch, one can determine the best time (the marginal value) for an animal to leave the current patch and move on to the next one. If an animal leaves the patch before this time, it will ________; if it waits to leave after this time, it will _________.

A) be able to take advantage of its peers' having already located the next patch; benefit by beating its competitors to a new food source.
B) be traveling when it could still be profitably foraging in the current patch; waste time continuing to search for food in an already depleted area.
C) benefit by beating its competitors to a new food source; be able to take advantage of its peers' having already located the next patch.
D) waste time continuing to search for food in an already depleted area; be traveling when it could still be profitably foraging in the current patch.

Question 24

Chipmunks will stuff food into their cheek pouches to carry back to their burrow. Giraldeau and Kramer (1982) found that laboratory chipmunks

A) carried seeds from seed trays (patches) in their cheek pouches only when the distance to the burrow was great; otherwise, they simply carried individual seeds one at a time.
B) spent less time at a seed tray when the distance between the seed tray (patch) and the burrow was increased.
C) spent more time at a seed tray when the distance between the seed tray (patch) and the burrow was increased.
D) were unable to adjust their food loads with varying distances between the seed tray (patch) and the burrow because of the physical constraints on the size of their cheek pouches.

Question 25

Reviews of the performance of the marginal value theorem have suggested that

A) animals, in fact, seem to prefer poor patches over rich ones.
B) foragers consistently stay for briefer periods of time in patches than predicted.
C) increased travel time leads to briefer time in patches.
D) patch residence times correlate with patch quality.

Question 26

The fact that animals as diverse as moose, hummingbirds, and locusts can select a food that redresses a specific nutritional need suggests that animals

A) balance specific nutritional needs with overall energy needs by eating a mixture of items.
B) eat to maximize energy intake.
C) generally meet their overall energy requirements as a side effect of attending to specific nutritional needs.
D) will eat to meet specific nutritional needs, even at the expense of minimum energy requirements for weight maintenance.

Question 27

Time spent checking other patches is time lost feeding. Research indicates that an animal is most likely to spend time "checking other patches"

A) as the quality of the current patch decreases.
B) when joined on the current patch by a conspecific.
C) when the animal has eaten enough and has some extra time.
D) when the current patch is totally depleted.

Question 28

Northwestern crows (Corvus caurinus) search along the waterline during low tide for whelks, or large snails. Which of the following statements about crows and/or the whelks they prey upon is TRUE?

A) Crows pick up a whelk and then carry it to a collection of whelks located in a safer feeding area away from the waterline.
B) Crows pick up a whelk, carry it over rocks, fly almost vertically upwards, then drop the whelk.
C) Large whelks are so heavy that carrying them costs more energy than the whelk supplies in calories.
D) Whelks are preyed upon only until clams are available, at which point the preference shifts entirely to clams.

Question 29

Which of the following "rules of thumb" do crows seem to follow when making dietary decisions?

A) Take the clam rather than the whelk.
B) Take the heaviest prey item.
C) Take the item easiest to carry.
D) Take the whelk rather than the clam.

Question 30

Changes in foraging behavior in the face of predation risk may be manifested by

A) avoiding dangerous places.
B) avoiding dangerous times of the day.
C) increasing vigilance when foraging.
D) all of the above.

Question 31

Cowlishaw (1997) studied the foraging behavior of a desert population of chacma baboons (Papio cynocephalus ursinus) and found that over 90% of their food energy was found in which type of habitat at the research site?

A) hills
B) plains
C) river bed
D) woodland

Question 32

Cowlishaw (1997) studied the foraging behavior of a desert population of chacma baboons (Papio cynocephalus ursinus) and found that the baboons spent the most time foraging in which type of habitat at the research site?

A) hills
B) plains
C) river bed
D) woodland

Question 33

When gerbils were offered a choice between foraging for seeds in a safe plot or in a risky plot (one exposed to the simulated light of a full moon or one visited by a trained owl flying overhead), they preferred the safe plot

A) as long as the number of seeds was the same in the two plots.
B) under all conditions.
C) when the risk involved the moonlight rather than the owl.
D) when the risk involved the owl rather than the moonlight.

Question 34

A whole class of foraging models has been developed that are referred to as producer/scrounger models. These have been created to explore issues related to

A) behaviors associated with predator avoidance.
B) the feeder's level of risk sensitivity.
C) the internal state of the feeding animal.
D) the presence of competitors at the feeding site.

Question 35

Dynamic state-variable models are a much more sophisticated way to capture the complexity of real-life foraging and are directed primarily at variations in

A) behaviors associated with predator avoidance.
B) the feeder's level of risk sensitivity.
C) the internal state of the feeding animal.
D) the presence of competitors at the feeding site.

Question 36

Risk sensitivity (with "risk" referring to variability in the food supply) has been documented in a variety of taxa, including insects, fish, birds, and mammals. It has been found to

A) be a relatively constant characteristic of a species, such that all individuals in that species tend to be either risk-averse or risk-prone.
B) be a relatively constant characteristic of an individual animal, such that the individual will be either risk-averse or risk-prone.
C) take the form of risk-aversion much more often than the models predict.
D) vary depending upon an individual animal's hunger level.