Resource use and overlap plays a central role in the
structuring of vertebrate communities. The mechanisms
by which organisms partition resources typically involve
differentiation in some combination of habitat use (at
both fine and coarse scales), timing of activity and diet.
Differences in niche-breadth among competing species
are ultimately the result of an evolutionary trade-off
between the ability to exploit a wide base of resources
and the efficient use of each one (Futuyma & Moreno
1988, MacArthur 1972). Although species occur along
a continuum of niche breadth, they are often considered
simply as specialists or generalists (Clavel et al. 2010,
Julliard et al. 2006). These two resource acquisition
strategies have been associated with important life-
1 Corresponding author. Email: jnpauli@wisc.edu
history traits: in general, specialists have lower dispersal
capacities (Brouat et al. 2004), and are more susceptible
to stochasticity and environmental change (Clavel et al.
2010, Sol et al. 2002) than generalists.As a consequence,
resource specialists are typically more prone to extinction
than generalists, and often the first species to be lost when
habitats are modified (Boyles & Storm 2007, Dunn et al.
2009, Laurance 1991).