Hiding behaviour in two cricket populations that differ in predation pressure

Despite evidence that predators and parasitoid flies influence the evolution of song structure in crickets, much less is known about the influence of predators and parasitoids on crickets' use of refuges. Individual field crickets, Gryllus integer, differ in the amount of time they spend hiding in refuges when placed into a novel environment. Here, we studied the hiding behaviour of crickets from two populations (Arizona and California, U.S.A.) that differ in predation pressure. Tethering experiments conducted at both habitats demonstrated that more predators occur in the Arizona population's habitat than in the California population's habitat. We also found more parasitoid flies, which are attracted to male song, in Arizona than in California. We tested hiding times of both male and female crickets from each of the two populations in the laboratory. Male Arizona crickets from the high-predation habitat hid longer when placed into a novel environment in the laboratory than male California crickets from a low-predation habitat, although females from the two populations did not differ. Since the crickets we tested were the first-generation laboratory population derived from field-caught mothers, differences in behaviour were due to either nongenetic maternal effects or genetic effects. These results suggest that hiding times of male crickets in these populations have been shaped by natural selection acting through predation pressure. (c) 2006 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.