The effect of dispersal on local population dynamics

Habitats in spatially structured populations are coupled by dispersal. Thus, local and global dynamics may be influenced by the dispersal strategy used. We study the consequences of various unconditional and conditional dispersal strategies to the local dynamics. We found that not only the magnitude but also the mode of dispersal may affect local dynamics significantly. Density dependent dispersal induces an additional amount of variability of the local dynamics because it interacts with the spatial and temporal variability of the environment via the local density. Therefore, the same dispersal strategy may induce quite different patterns of variability of local dynamics depending on the landscape. The structure and parameters of our model were guided by the population dynamics of black-headed gull (Larus ridibundus). Therefore, comparing patterns of our simulations with field patterns, we are able to make suggestions about the dispersal strategy used by this gull species.