Bardi M
J Math Biol. 1983;17(1):33-43. doi: 10.1007/BF00276113.
Various biological phenomena lead to single species models where the relative rate of increase is a non-monotone function of the density, i.e. depensation models. A brief survey of the literature and some new models are given. A nonlinear nonautonomous O.D.E. is proposed as a general depensation model in a periodically fluctuating environment. Results on existence, multiplicity and global stability of periodic solutions are given.