Vertical and diel niches modulate thermal selection by rainforest frogs.

Thermoregulatory behaviour determines an organism's body temperature and therefore its physiological condition, and may differ for organisms situated across climate gradients. Species' preferred or selected temperatures may be higher in warmer locations-referred to as coadaptation-or lower in warmer temperatures-countergradient variation. Here, we tested if rainforest amphibians exhibited coadaptation or countergradient thermal selection across an underappreciated spatial climate gradient (vertical height from forest floor to canopy) and separating diel activity (diurnal versus nocturnal behaviour).