Exam 34: Communities in Ecology

Two species of squirrel lived along a hillside in California. One species had a range that extended from sea level to about 5,000 meters in elevation; the other species had a principal range from 5,000 meters to 10,000 meters. However, when a viral epidemic greatly reduced the population of the low-elevation species, the high-elevation species increased its range down to 3,000 meters. This suggests that ________ was occurring and that coexistence was due to ________.

A really productive community is one that has a lot of:

Lichens represent mutualistic forms of life.

A zoologist has found that a certain species of woodpecker nests only in dense, old-growth forests and feeds on large insect larvae from the upper canopy. She has described this species':

Competition between members of two different species is:

Cowbirds and cuckoo birds that lay their eggs in another bird's nest for the new mother to care for are identified as:

Several lizard species have bright red lines or spots on their backs, and all are either toxic or poisonous to their predators. This is an example of:

In a typical ecosystem, an organism that is photosynthetic and whose removal would have a bigger impact than any other would be known as a:

Wolves and foxes may be competitors for small mammals as food in the forest.

Which of the following is an example of coevolution?

Lions on the African savanna are identified as ecological dominants.

Population cycles in herbivores are due to:

Wildebeest and zebras are abundant mammals on the African savanna. These species are identified a ecological dominants.

Resource partitioning:

An accidental spill of a pesticide locally wiped out one species of an endangered butterfly in coastal California. Several bird species had fed on this butterfly, but they switched prey items fairly quickly to more abundant moths, and thus the birds showed little change in population size. The endangered butterflies were:

Ecological dominants:

Mimicry is a common way for prey to avoid a predator.

A population biologist notes a curious fact when observing a population of small voles in a field in Michigan: although he traps and removes a significant percentage (>15 percent) of the breeding adults for study each year, the density of the voles does not seem to decrease in the following year. This suggests that ________ is occurring.

Which of the following is an example of intraspecific competition?

Explain the difference between a primary succession and a secondary succession. In which one would you expect soil fertility to be greater? Give an example of each type of succession.