The California Academy of Sciences Gulf of Guinea Expedition (2001) II. Additions and Corrections to Our Knowledge of the Endemic Amphibians of São Tomé and Príncipe

We present observations on the São Tomé Island endemic Hyperolius thomensis which indicate that it is one of the few African treefrogs known to utilize phytotelmata (tree holes) forbreeding. Ourfield work and observations strongly suggest that this island giant is restricted to primary forest, remnants of which are usually at higher elevations or inaccessible areas of São Tomé Island. Our locality data and field observations in a number of circumstances are not congruent with those of Loumont (1992). An examination of the data associated with her collections housed in the Natural History Museum of Geneva reveals that her data are not specific with regard to individual specimens and dates and, as a result, the status and distribution of the amphibian species on both islands may have been misinterpreted. We note that females of the endemic ranine ranid frog, Ptychadena newtonii, attain snout-vent lengths greater than other members of the genus, and that this species should therefore be considered an island giant. We describe and illustrate for the first time the males of Africa’s largest treefrog, the Príncipe Island endemic Leptopelis palmatus, provide figures illustrating the range of male and female color pattern polymorphism and comment on adult size dimorphism and size at metamorphosis.