01694naa a2200181 a 450000100080000000500110000800800410001910000150006024501440007526000090021952011360022865000210136465300170138565300200140265300140142270000210143677300550145719388922013-12-06       2013    bl ---       0--  u    #d1 aCAMPOS, Z.  aThermal relations of dwarf caiman, Paleosuchus palpebrosus, in a hillside streambEvidence for an unusual thermal niche among crocodilians.  c2013  aBody temperatures of 13 Paleosuchus palpebrosus, 7males and 6 females, were monitored by radio-telemetry during cold periods (dry season) and warm periods (wet and dry seasons) in a stream draining into the Brazilian Pantanal.The mass of the caimans varied from 2.5 to 20.0kg, and snout?vent length from 47.5 to 95.0 cm. Mean monthly body temperature was 21.6 C, and varied from 20.1 to 25.6 1C throughout the year. Body temperature was correlated with air and water temperature but did not differ between males and females. Unlike all other crocodilians investigated in detail to date, the caimans did not show evidence of attempts to obtain higher body temperatures when ambient temperatures were low, and had low and generally constant temperatures in relation to the surrounding air and water throughout the year. The caimans remained in burrows during cold periods in the dry season, which may explain why they did not seek higher temperatures. Tolerance of relatively low and constan body temperatures may be a key adaptation of species of Paleosuchus, allowing them to occupy environments inhospitable to other crocodilians.  abody temperature  aDwarf caiman  aThermal biology  aTolerance1 aMAGNUSSON, W. E.  tJournal of Thermal Biologygv. 38, p. 20-23, 2013.