| The Mount Lyell salamander (Hydromantes platycephalus) occupies high-elevation talus slopes in the Sierra Nevada. Passive rolling behavior of H. platycephalus observed by Garcia-Paris and Deban (1995) was proposed as an effective antipredator mechanism given the salamanders' rugged habitats. While the authors described methods used to test H. platycephalus for rolling behavior, they excluded important details such as the level of stimulus required for each salamander to roll. Therefore, I tested for the presence of rolling behavior in H. platycephalus in situ. In order to replicate the tests performed by Garcia-Paris and Deban (1995), I placed salamanders on a slanted surface and repeatedly tapped their heads and sides. After testing almost twice as many H. platycephalus individuals (n=20) as Garcia-Paris and Deban (1995, n = 12), I observed 4.6 times less body coiling (n=4) and did not witness any instances of passive rolling. I recommend additional tests to determine whether stronger stimuli will elicit passive rolling behavior in H. platycephalus. However, I propose that the behavior is less widespread than Garcia-Paris and Deban (1995) implied, and that it is likely an attempt to escape from falling rocks rather than predators. |