  Habitat destruction threatens the viability of many populations, but its full
consequences can take considerable time to unfold. Much of the discourse
surrounding extinction debts--the number of species that persist transiently
following habitat loss, despite being headed for extinction--frames ultimate
population crashes as the means of settling the debt. However, slow population
decline also opens an opportunity to repay the debt by restoring habitat. The
timing necessary for such habitat restoration to rescue a population from
extinction has not been well studied. Here we determine habitat restoration
deadlines for a spatially implicit Levins/Tilman population model modified by
an Allee effect. We find that conditions that hinder detection of an extinction
debt also provide forgiving restoration timeframes. Our results highlight the
importance of transient dynamics in restoration and suggest the beginnings of
an analytic theory to understand outcomes of temporary press perturbations in a
broad class of ecological systems.
