Evolution of migration rate in a spatially realistic metapopulation model
Authored by I Hanski, M Heino
Date Published: 2001
DOI: 10.1086/319927
Sponsors:
Academy of Finland
Finnish Centre of Excellence Programme
Platforms:
No platforms listed
Model Documentation:
Other Narrative
Mathematical description
Model Code URLs:
Model code not found
Abstract
We use an individual-based, spatially realistic metapopulation model to
study the evolution of migration rate. We first explore the consequences
of habitat change in hypothetical patch networks on a regular lattice.
If the primary consequence of habitat change is an increase in local
extinction risk as a result of decreased local population sizes, migration rate increases. A nonmonotonic response, with migration rate
decreasing at high extinction rate, was obtained only by assuming very
frequent catastrophes. If the quality of the matrix habitat
deteriorates, leading to increased mortality during migration, the
evolutionary response is more complex. As long as habitat patch
occupancy does not decrease markedly with increased migration mortality, reduced migration rate evolves. However, once mortality becomes so high
that empty patches remain uncolonized for a long time, evolution tends
to increase migration rate, which may lead to an ``evolutionary
rescue{''} in a fragmented landscape. Kin competition has a quantitative
effect on the evolution of migration rate in our model, but these
patterns in the evolution of migration rate appear to be primarily
caused by spatiotemporal variation in fitness and mortality during
migration. We apply the model to real habitat patch networks occupied by
two checkerspot butterfly (Melitaea) species, for which sufficient data
are available to estimate rigorously most of the model parameters. The
model-predicted migration rate is not significantly different from the
empirically observed one. Regional variation in patch areas and
connectivities leads to regional variation in the optimal migration
rate, predictions that can be tested empirically.
Tags
Dynamics
Environments
Consequences
Extinction
Landscapes
Butterfly metapopulation
Habitat persistence
Dispersal strategies
Subdivided populations
Kin competition