SEASONAL DISTRIBUTION AND CIRCADIAN ACTIVITY INTHE TROGLOPHILE LONG-FOOTED ROBBER FROG,ELEUTHERODACTYLUS LONGIPES (ANURA:BRACHYCEPHALIDAE) AT LOS RISCOS CAVE,QUERETARO, MEXICO: FIELD ANDLABORATORY STUDIES

摘要

Los Riscos Cave belongs to the El Abra limestone and its geographicallocation is in the Sierra Gorda in the State of Queretaro, Mexico. The cave has a highfaunal diversity that includes arthropods and some vertebrates, such as vampire bats andanurans, and includes the robber frog Eleutherodactylus longipes (Baird, 1859). Theabundance of the robber frog changes non-randomly between dry and rainy seasons andis related to the search for humid conditions inside the cave. In addition, the robber frogwas located in areas where some scattered light may influence its dispersion inside thecave; and therefore, its activity. Frogs displayed spontaneous circadian rhythms oflocomotor activity from the first days of the experimental observation in constantdarkness. The average period of circadian rhythms was 24.85 ± 0.93 h indicating, inisolated conditions, a diurnal activity. When exposed to artificial light-dark cycles, theanimals lacked daily activity rhythms, and ultradian activity was observed. Thepreference for high humidity and low illumination in the cave and a partial endogenouscircadian rhythmicity confirm the troglophilic affinity of the robber frog to caveenvironments.