Exam 14: Competition

In Brown and Davidson's study of seed-eating rodents and ants in Arizona, the number of rodents _______ when ants were removed, and the number of ant colonies _______ when rodents were removed.

Which statement about allelopathy is true?

In bumblebees (Bombus) species that live together, they usually have different length proboscises that allow them to collect nectar from different flowers. This is an example of

Two species of flour beetles, Tribolium castaneum and Tribolium confuum, are competing according to the Lotka‒Volterra equations. If the α of T. confuum on T. castaneum is 0.4, one can assume that the addition of 200 T. confuumi individuals would depress the population growth of T. castaneum by the same amount as the addition of _______ T. castaneum individuals would.

Which of the following cannot be a resource for an organism?

Which statement about zero population growth isoclines of two competing species is true?

Which statement describes a finding of Wilson and Tilman's studies of the grass Schizachyrium scoparium?

A population of Teleopsis (a stalk-eyed fly) with 20,000 individuals and a carrying capacity of 40,000 follows the logistic growth equation. Its growth rate under ideal low-density conditions is 0.2 per day. The addition of 30,000 houseflies is enough to bring the population growth of Teleopsis to zero. What is the competition coefficient of the effect of the housefly on Teleopsis?

A population of white oak trees with 500 individuals and a carrying capacity of 1,500 follows logistic growth. Under ideal low-density conditions, its growth rate is 0.15 per year, but it faces competition from a population of 1,000 Chapman oaks with an α of 0.5. What is the expected growth of the population of white oaks in the next year?

Refer to the figure. The figure shows the relationship between the growth rates (on a log scale) of individual fish and the similarity of the fish to their competitors. Assuming that populations with faster growth rates are more likely to have greater population growth, which principle or concept does the figure support?

Suppose that a species of moss cannot coexist with a superior competitor unless there is periodic disturbance. This species is also a frequent disperser. Which conclusion is most likely?

Based on Paine's studies, what has allowed the sea palm to persist in shoreline areas despite the presence of a superior competitor (Mytilus)?

Character displacement is likely to _______ the competition coefficients in two competing species and to _______ resource partitioning.

Two similar rodent species are consistently more different from each other when they occupy the same habitat than when they live separately. What is the most likely explanation for the increased divergence when they live together?

Which statement about Tilman and colleagues' studies of the diatoms Synedra and Asterionella is true?

Suppose that two species of Darwin's finches live on the same island and eat seeds, but one species tends to eat larger seeds than the other one does. Based on this observation, we can conclude that these species are engaged in

Refer to the figure. What percent of 0.99-1.16 mm seeds were eaten by rodents?

Which statement was supported by Stomp and colleagues' study of the partitioning of resources between two species of Baltic Sea cyanobacteria?

Two species of grasshoppers live in the same area. They both feed on plants, but the presence of one species does not affect the survival or the reproduction of the other. What type of competition is this?

A population at the zero population growth isocline is