Behavioural evidence of a humidistat: a temperature-compensating mechanism of hydroregulation in spotted salamanders.

ABSTRACT: The ability to control hydration state is essential for terrestrial species, especially amphibians, which are highly susceptible to dehydration. Here, we examined how temperature (17°C versus 22°C) influenced behavioural hydroregulation in spotted salamanders (Ambystoma maculatum) using a laboratory humidity gradient. Salamanders defended a constant vapour pressure deficit (VPD) between temperatures by targeting higher relative humidity at 22°C than at 17°C, possibly to compensate for increased evaporative demand at warmer temperatures. Individuals selecting higher VPDs experienced greater evaporative water loss (EWL), with larger salamanders losing more water than smaller ones after accounting for temperature. Together, these results highlight a trade-off among body size, humidity prefere

SUBMITTER: Giacometti D 

PROVIDER: S-EPMC12148020 | biostudies-literature | 2025 May

REPOSITORIES: biostudies-literature