For more information on Relative Distribution Methods, including the preface to the book, data sets, and software to implement the methods are available from the Relative Distribution website. The main software is the R software package reldist: Tools for the comparison of distributions. This includes nonparametric estimation of the relative distribution PDF and CDF and numerical summaries as described in Relative Distribution Methods in the Social Sciences by Mark S. Handcock and Martina Morris.
For more information on R software to implement the statistical methods described in the paper Resource utilization by an avian nest predator: relating resources to a probabilistic measure of animal space use, by John M. Marzluff, J. J. Millspaugh, P. Hurvitz, and Mark S. Handcock, Ecology, 2004, 85:1411-1427, see the Resource Utilization Function Estimation website.