Expedition 2000 to Isla
Herpetological Survey Methods
There has never been a focused effort to collect and assess the amphibians and reptiles from Isla Guadalupe for similar reasons described in the Entomology section. The only two herpetofaunal records known from the island were obtained during visits by Reinoehl in 1949 (Caretta caretta) and Limbaugh and Rechnitzer in 1953 (tadpoles of Hyla regilla). Nothing else is known about the island's herpetofauna. Because many amphibians and reptiles are secretive and nocturnal, fortuitous collecting by persons specialized in other scientific disciplines is rare. The diversity of habitats and the island's rugged terrain lead to the possibility of finding previously undocumented species. If any additional species are found, there is a good possibility that they will represent undescribed taxa in light of the island's geologic history and high endemism. Of the two herpetofaunal records, only the terrestrial account will be pursued. Adult individuals of Hyla regilla will be sought to confirm its presence on the island, assure the proper taxonomic assignment of the tadpole specimens, and evaluate whether it is a native or introduced population. Both the main island and islets with a significant floral component will be surveyed.
Standard herpetological collecting techniques will be used in obtaining specimens, including some of the same methods employed in the entomological survey (e.g. pit fall traps). Other techniques include hand collecting and collecting by noose. Nocturnal surveys will be conducted by hiking with propane lanterns starting at sunset. All specimens will be photographed alive to document color pattern and preserved in the field using standard fixation methods. Tissue samples will be taken and stored in a tissue storage buffer before preservation. GPS data will be recorded for every individual collected. A total of no greater then ten specimens of any one species, from any single population, will be obtained. For populations believed to more sensitive to collection, as determined by the collections team, smaller numbers of individuals will be obtained.
Specimens will be sorted and deposited evenly between the Department of Herpetology at the San Diego Natural History Museum and the herpetological collection at the Centro de Investigaciónes Biolólogicas del Noroeste (CIBNOR) in La Paz, México. It is anticipated that no CITES listed animals will be among those found on Isla Guadalupe, so CITES permits most likely will not be necessary. Exportation of specimens to San Diego will be taken by hand through the Otay Mesa port of entry, declared, and the submission of the appropriate paperwork filed with the United States Fish and Wildlife Service.