Reproductive effort in viscous populations

Here I study a kin selection model of reproductive effort, the allocation o f resources to fecundity versus survival, in a patch-structured population. Breeding females remain in the same patch for life. Offspring have costly, partial long-distance dispersal and compete for breeding sites, which beco me vacant upon the death of previous occupants. The main result is that the evolutionarily stable reproductive effort decreases as offspring dispersal rate increases. The result can be understood as follows: In a well-mixed p opulation with global competition, neither adults nor juveniles compete wit h relatives, but in a patch-structured population with dispersal restricted to the juvenile phase, juveniles experience relatively less competition wi th relatives than adults, thus making juveniles relatively more valuable. B ecause this asymmetry between adults and juveniles decreases with the dispe rsal rate, so does the evolutionarily stable level of allocation to fecundi ty.