The tail of the dispersal kernel of individual movement plays a critical role in the spatial spread of infectious disease, invasive species, and other spreading phenomena. However, most studies where the dispersal kernel has been estimated from observed natural systems have assumed homogeneous dispersal in space, even though non-uniform use of space (i.e., resource selection) has long been recognized as important in many systems. In our project, we explore the consequences of ignoring terrain heterogeneity when estimating parameters governing the tail of a dispersal kernel. We show that ignoring resource selection in general leads to estimates of dispersal kernels with heavier tails than the true kernels used for simulation. In addition, this often leads to predictions of the rate of spatial infectious disease spread that are much faster than the true spread through a population that is moving across patchy terrain.