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 vs. 22°C) influenced behavioral hydroregulation in spotted salamanders (Ambystoma maculatum) using a laboratory humidity gradient. Salamanders defended a constant vapour pressure deficit (VPD) between temperatures by targeting higher RH 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 preference, and desiccation tolerance. Salamanders also rehydrated faster at 22°C than 17°C, highlighting temperature-dependent water uptake rates. Our finding that salamanders regulated a constant driving force of evaporation between temperatures suggests the ability to detect rates of EWL. Local evaporative cooling of the skin is a plausible mechanism: if moist-skinned ectotherms show local evaporative cooling on exposed surfaces but not on those in contact with the substrate, then the temperature gradient between dorsal and ventral skin could act as an effective cue to detect the drive for EWL. Ultimately, our study underscores the complexity of amphibian hydroregulation and emphasises the role of behaviour in maintaining hydration state.
Behavioural evidence of a humidistat: a temperature-compensating mechanism of hydroregulation
Open Access
Using the reactive scope model to redefine social stress in fishes
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JEB grants to support junior faculty
Learn about the grants that we launched in 2023 to support junior faculty from two of our awardees: Erin Leonard, Early-Career Researcher (ECR) Visiting Fellowship recipient, and Pauline Fleischmann, Research Partnership Kickstart Travel Grant recipient. The next deadline to apply is 6 June 2025.
Thirteen-lined ground squirrels survive extraordinarily low blood oxygen
Brynne Duffy and colleagues reveal that thirteen-lined ground squirrels are true hypoxia champions surviving extreme low blood oxygen, down to just 34% oxygen, when they emerge briefly from hibernation.
The Company of Biologists Workshops
For the last 15 years, our publisher, The Company of Biologists, has provided an apt environment to inspire biology and support biologists through our Workshops series. Read about the evolution of the Workshop series and revisit JEB's experience with hosting the first Global South Workshop.
Fast & Fair peer review
Our sister journal Biology Open has recently launched the next phase of their Fast & Fair peer review initiative: offering high-quality peer review within 7 working days. To learn more about BiO’s progress and future plans, read the Editorial by Daniel Gorelick, or visit the Fast & Fair peer review page.
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