The role of behavioral ecology in management of endangered pupfishes

Authors: Jennifer Gumm

Year: 2012 (xliv)

Abstract

Management strategies based on behavioral phenotypes may be effective when inter- or intra-specific interactions lead to declines in genetic variation or size of a population. Population and community composition can influence reproductive behaviors, fitness as well as biodiversity. Here, I highlight two systems where behavioral studies influence management strategies in endangered pupfishes (genus Cyprinodon). Within a population, the social environment has important consequences for individual reproductive behavior and fitness. In the endangered Comanche Springs pupfish, C. elegans, males express one of three alternative reproductive tactics (ARTs); territoriality, satellite behavior, or female mimicry. Field studies have established that population composition facilitates spawning by female mimics in the natural population and that aggression towards female mimics is dependent on local social environments. Using behavioral and genetic methods in a laboratory study, I directly tested the fundamental relationship between ecological, demographic variables and evolutionary processes (i.e. sexual selection) by quantifying the fitness outcomes of males expressing ARTs. Population density and sex ratio influenced aggressive behavior and reproductive success of males expressing different tactics. On the community level, interspecific dynamics can influence individual behavior and population size. In a desert spring system in West Texas, an endangered egg predator, Gambusia nobilis altered breeding behavior and contributed to the decline of the endangered Leon Springs pupfish, C. bovinus. Habitat restoration resulted in decreased egg predation pressure and a corresponding resurgence in the pupfish population. Direct conflicts between multiple endangered species present unique challenges to conservation and, this is the first example of effective management of deleterious interactions between two endangered species using habitat restoration to alter behavioral patterns.