Author: Anonymous

Briefly explain the phenomenon of territoriality and provide an example of a signal an animal can use to designate a territory. Then explain one advantage and one disadvantage to the organism maintaining a territory.  Finally, explain how territorial behavior typically influences population dispersion at the landscape level. 

A) A team of ecologists is studying a population of snails in a marsh. During the first sampling, they capture and mark 120 snails before releasing them back into the population. A week later, they recapture 150 snails, 30 of which are marked. Calculate the size of the snail population. (Need to show calculations to receive full credit). B) After carefully observing the recaptured animals, the researchers discovered that 10% of the marked snails actually lost their marks during the study period. Adjust the population estimate to account for this mark loss. Hint: The true number of marked snails in the second sample (R′) can be recalculated as: R′=R/(1−Mark Loss Rate). (Need to show calculations to receive full credit).

A metapopulation of frogs is distributed across five ponds. Data on local extinctions and recolonizations are presented below: Pond Local Extinction Events (5 years) Recolonization Events (5 years) 1 2 2 2 3 1 3 0 0 4 5 4 5 1 1 Which pond is most at risk of permanent extinction and why?

Part 1 – Multiple Choice/Fill-In/True or False/Matching Questions.

A researcher is studying the interaction between a bird species and a small mite species that lives on the bird’s feathers. The mites feed on the bird’s blood, causing the bird to lose feathers and expend more energy maintaining its health. The mites benefit from feeding on the bird, but the bird’s health declines as a result of the interaction. Based on this information, which of the following types of interactions best describes this relationship?

The level of ecological organization that focuses on a single living individual is the [organism] level, while the level that examines groups of the same species living in the same area is the [population] level.

Consider a population of insects starting at 100 individuals with a replacement rate of 1.05 per month. Then, consider that at three months, a predator is introduced, reducing the replacement rate to 0.90 per month. Calculate the population at A) 3 months and then at B) 6 months. (Need to show calculations to receive full credit).

Match each factor with whether it is density-dependent or density-independent:

Which of the following scenarios best illustrates optimal foraging in the presence of predation risk?

A species of plant, Species A, normally grows in nutrient-poor soils and is restricted to a narrow range of environments where it can survive. However, when Species A forms a relationship with a species of nitrogen-fixing bacteria, Species B, it can thrive in a much wider range of soil types, including nutrient-rich soils that were previously unsuitable. Which of the following best describes the relationship between the niches of Species A?