Tom Miller (a prof here at Rice) and Brian Inouye have a paper out in Ecology (paper, appendices) that confronts two-sex models of dispersal with empirical data. They conducted the first confrontation of two-sex demographic models with empirical data on lab populations of bean beetles Callosobruchus. Their R code for the modeling work is available at Ecological Archives (link here). Here is a figure made from running the five blocks of code in ‘Miller_and_Inouye_figures.txt’ that reproduces Fig. 4 (A-E) in their Ecology paper (p = proportion female, Nt = density). Nice!

A: Saturating density dependence
B: Over-compensatory density dependence
C: Sex-specific gamma’s (but bM=bF=0.5)
D: Sex-specific b’s (but gammaM=gammaF=1) Sex-specific b’s (but gammaM=gammaF=2)