Exam 12: Predation

In the studies of clipping in gentians, plants that were clipped early in the season had _______ number of fruits, and plants that were clipped late in the season had _______ number of fruits.

Use the following simple predator-prey relationships to answer the question (assume no other interactions exist in this system): Mice eat grain grown by a farmer before it can be harvested. The mice are consumed by several species of snakes, which themselves are consumed by hawks. If the population of snakes was suddenly wiped out by disease, explain the short-term effects on the grain, mice, and hawk populations, and why these effects would be observed.

The Lotka‒Volterra predator‒prey model of population growth

When animals are exposed to chronic stress, the stress response suppresses all of the following except

The introduction of arctic foxes to some of the Aleutian Islands led to a drastic _______ in nitrogen-rich guano, and this change had the effect of transforming the islands from grassland to _______.

Refer to the figure. The graphs show different relationships between the proportion of prey that are tubificids and the proportion that are eaten by predators (guppies). Based on research by Murdoch et al., which graph best represents the foraging habits of guppies?

Huge numbers of adult periodic cicadas emerge simultaneously from pupae at intervals of either 13 or 17 years. This phenomenon is most similar to which of the following?

Department of Natural Resource managers, biologists, and foresters in many states work together to successfully manage game populations by determining the number of deer, bear or other animals that can be harvested each year. Harvest numbers can fluctuate based on climatic factors and natural events that affect plant production. For example, squirrels have been documented to have additional litters in masting years. Additionally, in the years following oak tree mastings, the number deer and squirrels that can be harvested tends to increase. Explain why mastings can influence deer and squirrel populations and the benefit of them to the oak tree.

Züst and colleagues found that

Which observation led ecologists to conclude that resource limitation is not the only factor driving snowshoe hare cycles?

Suppose that a predatory fish eats only minnows and the predator‒prey interaction follows Lotka‒Volterra dynamics. The intrinsic growth rate of minnows in the absence of predators is 0.2 per month, and the mortality rate of the predatory fish in the absence of minnows is 0.1 per month. The capture efficiency rate is 0.004, and the efficiency at which minnow biomass is converted into predator biomass is 0.25. The minnow population size will increase only if the number of predatory fish is

Refer to the figure. On which date(s) was the predator's density 20?

Croll et al. studied the effects that long-term inhabitation of artic foxes had on the ecosystems of the Aleutian Islands. Based on their findings, which of the following statements is true?

Which statement about parasitoids is false?

Which statement about predators and herbivores is true?

Refer to the figure. You are studying the composition of the diet of a predator species. Among other prey, this predator preys upon species A. You collect data on how species A's abundance is related to the percent of the predator's diet composed of this species. Based on the figure, at what percent of species A is the predator's diet comprised of 50% species A and 50% other prey?

In the Lotka‒Volterra predator‒prey model, an increase in the capture efficiency (a) should lead to _______ in the long-term average number of predators and _______ in the long-term average number of prey.

Refer to the figure. You are studying the composition of the diet of a predator species. Among other prey, this predator preys upon species A. You collect data on how species A's abundance is related to the percent of the predator's diet composed of this species. Based on the figure, at which point would predator consumption patterns match the predicted consumption patterns if the predator's percent of consumption matched the percent of species A in terms of total prey base?

Military camouflage is analogous to what type of biological defense against predation? Explain how camouflage works as a defense.

Which statement best describes the relationship between snow geese and plants in the salt marshes that border the Hudson Bay?