MACROHABITAT AND MICROHABITAT USAGE BY TWO SOFTSHELL TURTLES (TRIONYX TRIUNGUIS AND CYCLANORBIS SENEGALENSIS) IN WEST AND CENTRAL AFRICA

摘要

No field studies have been conducted characterizing the habitat characteristics and eventual spatial resource partitioning between softshell turtles (family Trionychidae) in West and Central Africa. Here, we analyze the macrohabitat, microhabitat (along four variables), and apparent population abundance of Nile Soft-shelled Terrapin (Triottyx triunguis) and Senegal Flap-shelled Terrapin (Cyclanorbis senegaknsis) by collating 22 y of data (1995-2017) from 11 countries in West and Central Africa. We found that the carapace length of T. triunguis was significantly larger than C senegalensis. Qualitative observations on the apparent population abundance suggests that the smaller species was relatively common in most of the sampled sites, whereas the larger species was often rare or even very rare. We found the two species in a variety of macrohabitats, and a clear difference between them was not apparent in our data. Instead, at the microhabitat scale, the two species differed significantly in all the four microhabitat variables considered in this study. Overall, the data we present are consistent with a general pattern of resource partitioning previously highlighted for freshwater turtle communities worldwide, where sympatric species tend to partition the microhabitat resources and not the available macrohabitats. Because T. triunguis seemed rare in most of the surveyed sites, we suggest that more field investigations should be undertaken to understand whether the current status of Vulnerable is suited for this species, or if a more highly threatened category on the Red List should be adopted.