Where are the turtles when they are not? Underwater refuges used by Hydromedusa tectifera COPE, 1869 in a suburban stream.

SEMEÑIUK MB; CASSANO MJ; SÁNCHEZ R M; PALUMBO EO; ALCALDE L

Urban Ecosystems

Springer

Año: 2020 vol. 23 p. 1289 - 1297

1083-8155

Habitat requirements of Hydromedusa tectifera from an urban impacted stream from the Buenos Aires province, the Rodriguezstream, are here studied.We describe the type of underwater refuges, how they are used in different stream sections, stream margins,year season, size class and sex of the individuals, and analyze patterns of recurrence and aggregative use of refuges. Fieldwork wascarried out from March 2017 to January 2018. Turtles were caught manually recording the following variables: site, transect andmargin, sex, straight carapace length, andweight. Substrate types are differently used according to stream section, stream margin, yearseason and size class of individuals, but no difference was found between sexes. In the whole stream, most used refuges were thehollows on the margins (55.05%), followed by marginal aquatic vegetation (19.27%). Turtles of all class sizes and both sexes refugeinto hollows on the stream margins. Despite different microhabitats provide refuge to turtles during all year seasons, hollows are themost important refuge during extreme cold and extreme hot seasons. In addition, turtle recaptures evidence a recurrence andaggregative pattern in the use of refuges. This information provides insight into the key aspects of the microhabitat requirementsof the species andwill be certainly useful in mitigating and preventing negative effects of the current streammanagement policies. It isworth highlighting the need to keep the stream margins unaltered to favor the presence of turtles in urban environments.