Evol Ecol Res 3: 795-804 (2001) Full PDF if your library subscribes.
Intrapopulation variation in endurance of Galápagos lava lizards (Microlophus albemarlensis): evidence for an interaction between natural and sexual selection
Donald B. Miles,1
Howard L. Snell2,3 and Heidi M. Snell3
1Department of Biological Sciences, Ohio University, Athens, OH 45701, 2Department of Biology and Museum of Southwestern Biology, University of New Mexico, Albuquerque, NM 87131, USA and 3Charles Darwin Research Station, Puerto Ayora, Isla Santa Cruz, Galápagos, Ecuador
Variation in the risk of predation may profoundly affect the evolution of anti-predator behaviours. Theory predicts that selection would favour enhanced locomotor capacity in high-risk environments, such as open habitats. An earlier study demonstrated significant intrapopulation and intersexual variation in wariness and sprint speed among the lava lizards (Microlophus albemarlensis) that was concordant with presumed risk of predation on Isla Plaza Sur in the Galápagos Archipelago. In particular, males and females from sparsely vegetated areas had greater approach and flight distances than those of more highly vegetated areas; males were also faster than females. We now compare endurance capacities of males and females from the same population on Isla Plaza Sur. We predicted the higher presumed risk of predation in the sparsely vegetated region would favour enhanced performance capacities. In addition, we predicted that sexual selection for territory defence would favour males that had the ability to flee long distances. Lizards from the sparsely vegetated area did have higher endurance than those from the vegetated area. Males had higher endurance times than females, but this difference was an outcome of body size, which was inconsistent with the sexual selection hypothesis. The significant differences in endurance between locations combined with the absence of dimorphism in performance suggest that the intrapopulation differences are an outcome of natural selection for predator escape.
Keywords: endurance capacity, Galápagos, individual variation, lizard, Microlophus albemarlensis, natural selection, predation, sexual selection.
DOWNLOAD A FREE, FULL PDF COPY
IF you are connected using the IP of a subscribing institution (library, laboratory, etc.)
or through its VPN.
© 2001 Donald B. Miles. All EER articles are copyrighted by their authors. All authors endorse, permit and license Evolutionary Ecology Ltd. to grant its subscribing institutions/libraries the copying privileges specified below without additional consideration or payment to them or to Evolutionary Ecology, Ltd. These endorsements, in writing, are on file in the office of Evolutionary Ecology, Ltd. Consult authors for permission to use any portion of their work in derivative works, compilations or to distribute their work in any commercial manner.
Subscribing institutions/libraries may grant individuals the privilege of making a single copy of an EER article for non-commercial educational or non-commercial research purposes. Subscribing institutions/libraries may also use articles for non-commercial educational purposes by making any number of copies for course packs or course reserve collections. Subscribing institutions/libraries may also loan single copies of articles to non-commercial libraries for educational purposes.
All copies of abstracts and articles must preserve their copyright notice without modification.