Does behavioral thermal tolerance predict distribution pattern and habitat use in two sympatric Neotropical frogs?

• Published in: PloS one 2020-09, Vol.15 (9), p.e0239485-e0239485
• Main Authors: Díaz-Ricaurte, Juan C, Serrano, Filipe C, Guevara-Molina, Estefany Caroline, Araujo, Cybele, Martins, Marcio
• Format: Article
• Language: English
• Subjects: Abundance; Amphibians; Animal spatial behavior; Animals; Anura - physiology; Behavior; Behavior, Animal - physiology; Biological research; Biology and Life Sciences; Body temperature; Body temperature regulation; Climate change; Daily temperatures; Distribution patterns; Ecology and Environmental Sciences; Ecosystem; Frogs; Habitat utilization; Habitats; Heat tolerance (Biology); Hydration; Influence; Leptodactylidae; Maximum temperatures; People and places; Physiological aspects; Physiology; Social Sciences; Species; Sympatric populations; Sympatry - physiology; Temperature; Temperature tolerance; Thermal stress; Thermotolerance - physiology; Tolerances; Zoogeography
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0239485

Environmental temperatures are a major constraint on ectotherm abundance, influencing their distribution and natural history. Comparing thermal tolerances with environmental temperatures is a simple way to estimate thermal constraints on species distributions. We investigate the potential effects of behavioral thermal tolerance (i. e. Voluntary Thermal Maximum, VTMax) on anuran local (habitat) and regional distribution patterns and associated behavioral responses. We tested for differences in Voluntary Thermal Maximum (VTMax) of two sympatric frog species of the genus Physalaemus in the Cerrado. We mapped the difference between VTMax and maximum daily temperature (VTMax-ETMax) and compared the abundance in open and non-open habitats for both species. Physalaemus nattereri had a significantly higher VTMax than P. cuvieri. For P. nattereri, the model including only period of day was chosen as the best to explain variation in the VTMax while for P. cuvieri, the null model was the best model. At the regional scale, VTMax-ETMax values were significantly different between species, with P. nattereri mostly found in localities with maximum temperatures below its VTMax and P. cuvieri showing the reverse pattern. Regarding habitat use, P. cuvieri was in general more abundant in open than in non-open habitats, whereas P. nattereri was similarly abundant in these habitats. This difference seems to reflect their distribution patterns: P. cuvieri is more abundant in open and warmer habitats and occurs mostly in warmer areas in relation to its VTMax, whereas P. nattereri tends to be abundant in both open and non-open (and cooler) areas and occurs mostly in cooler areas regarding its VTMax. Our study indicates that differences in behavioral thermal tolerance may be important in shaping local and regional distribution patterns. Furthermore, small-scale habitat use might reveal a link between behavioral thermal tolerance and natural history strategies.