The Presence of Heterospecifics in a Particular Habitat Could Have

The presence of heterospecifics in a particular habitat could have both costs and benefits for an animal considering whether to settle there. When Forsman and colleagues (2002) tested that idea by examining whether the presence of resident titmice influenced the settlement and fitness of migrant pied flycatchers, they found that

A) brood sizes of flycatchers were smaller in patches where numbers of titmice had been experimentally increased than in patches from which titmice had been removed.
B) flycatchers breeding closer to titmice had smaller nestlings than those breeding farther away.
C) flycatchers preferred nest boxes placed near an active titmouse nest to those located further away.
D) flycatchers tended to arrive later on forest patches where titmice numbers were increased than on patches where titmice had been removed.