The number of territories available for song sparrows when returning from their wintering grounds would be considered a:

Each stage of community change during succession is called a _____ stage.

Energy that an organism uses to add to its biomass is

The following are advantages of ectoparasites except:

When an animal eats fruit with hard seeds that cannot be digested and are excreted whole as a waste product, the seeds constitute _____ energy.

As a rule of thumb, ecologists use _____ as a value for food chain efficiency.

In the SIR model, if rate of recovery of infected individuals is fast then:

When two species have evolved a mutualistic relationship, if one species begins to provide less of a benefit, we predict that the other species will

The following are characteristics of ecotones EXCEPT:

A pioneer species is _____ species to arrive at a site.