Effects of Limb Length, Body Mass, Gender, Gravidity, and Elevation on Escape Speed in the Lizard Psammodromus algirus

Francisco J Zamora-Camacho, Senda Reguera, M Virtudes Rubiño-Hispán, Gregorio Moreno-Rueda. Evolutionary Biology. June 2014. Most animals rely on their escape speed to flee from predators. Here, we test several hypotheses on the evolution of escape speed in the lizard Psammodromus algirus. We test that: (1) Longer limbs should improve speed sprint. (2) Heavier lizards should be impaired regarding their sprint speed ability, suggesting a trade-off between fat storage and escape capability. (3) Males should achieve faster speeds due to their higher exposure to pre-dators. (4) Gravid females, with increased body mass, should perform lower speed than non-gravid females. And (5) there are inter-population differences in sprint speed across an elevational gradient. We measured lizards sprint speed in a lineal raceway in the laboratory, filming races in standardized conditions and then calculating their maximal speed. Leer más.