Research Interests Experimental studies of lizard and spider colonization and competition on islands. Experimental food-web manipulation as it affects herbivores, intermediate predators, and producers. Mathematical models of population interactions, territory size, food-web effects, and parasitoid occurrence; feeding strategies; island ecology; lizard population biology; predation; and resource partitioning. Development of methods for estimating home-range area and independence of successive observations. Analysis of size differences among certain hawks and lizards, with reference to the "null-model" controversy in community ecology.