Microhabitat Use by Tropical Tadpoles and the Effect of Riparian Vegetation Degradation

ABSTRACT Understanding species' microhabitat requirements is crucial to assessing their vulnerability, particularly in regions undergoing rapid environmental change. Paradoxically, for many threatened species, this knowledge remains poorly explored. We investigated the environmental variables influencing pool use by tadpoles of Incilius spiculatus, a Mexican microendemic toad, to understand how undergoing habitat changes can affect it. We worked along reproductive sites in riverbanks where small‐scale agriculture has recently increased. By measuring physical and chemical characteristics of used and unused pools, we identified the variables influencing their use. We also measured air and water temperatures across three years and water temperature changes along a canopy cover gradient. Tadpole pool use was associated with specific ranges of canopy cover, organic matter, pool depth, and water temperature. Over three years, air and water temperatures increased, and canopy cover decreased. Notably, tadpoles kept selecting available pools at a temperature range around 19°C and with canopy coverage of at least 60%, suggesting specific preferences. Measurements on water temperature in a canopy cover gradient showed that locally, temperature can increase up to 1°C with riparian vegetation reduction. We provide information of microhabitat needs for tadpoles of an endangered tropical toad whose populations are considered decreasing by fragmentation. Our results suggest tadpole vulnerability to water temperature rise exacerbated by deforestation as another threat. This is the first study focused on tadpole requirements and threats for this tropical species, a crucial knowledge to design restoration measures that incorporate habitat needs of both amphibian life stages and understand possible similar responses in other tropical amphibians.