12Temperature affects most aspects of ectotherms' life history, including physiology and 13 behavior. Studying thermal sensitivity of jumping performance in frogs can help 14 understanding the influence of temperature on different aspects of frog life. Still, studies 15 on the effects of temperature on amphibians are commonly carried out on terrestrial and 16 tree species, creating a gap for aquatic species. We experimentally tested the thermal 17 sensitivity of jumping performance of the Uruguay Harlequin Frog, Lysapsus limellum, 18 assessing three measures: response time, distance of first jump, and total distance 19 travelled. We hypothesized that individuals submitted to extreme temperatures would 20 increase response time, decrease first jump distance, and increase total jump distance.
21We used an arena with a gradient of air temperature (Ta) ranging from 20 to 40 ºC. We 22 placed frogs at different Ta and stimulated them to jump. Then, we analysed the 23 influence of Ta on the three estimates of jumping performance, using generalized 24 additive models. We found that temperature affected all three measurements of jumping 25 performance, but some relationships were stronger than others. Extreme temperatures 26 increased response time, reduced first jump distance, and increased total distance. The 27 effect was weaker for response time and first jump distance, but substantially stronger 28 for total distance jumped. Although individuals under extreme temperatures experience 29 a reduced jumping performance, they travelled longer distances to find areas with 30 milder temperatures. Thus, we showed that L. limellum thermoregulates by means of 31 behavior, moving through places at different thermal conditions. Additionally, benefits 32 of displacing to thermally suitable places -in terms of enhanced jumping performance-33 are bigger than the costs of jumping at reduced locomotor performance, at least under 34 experimental conditions. Our results can help understand how climate change affects the 35 locomotor performance of Neotropical amphibians. 36 37 thermoregulation. 38 42 in two ways. Firstly, through a top-down effect, when temperature variation is perceived 43 by the central nervous system and modulates behavior. Secondly, through a bottom-up 44 effect, in which temperature variation changes biochemical reaction rates, which alters 45 multiple cellular and systemic processes that consequently affect the organism as a 46 whole (Abram et al., 2017). 47 Thermal ecology includes two main aspects: thermal sensitivity (i.e. the 48 dependence of physiological performance on temperature) and thermoregulation (i.e.49
