Warmer water is forcing amphibians to rethink dinner—but the dietary “workaround” may run out before temperatures peak. In a new international study published in Scientific Reports (lead author: Dr Sara Bento), tadpoles of the Iberian spined toad (Bufo spinosus) actively shift feeding strategies as rearing temperatures rise, consuming more plant-derived material and eating more overall.
Researchers framed the question around physiological constraints. Like other cold-blooded animals, amphibians depend on ambient conditions to regulate growth and development. When temperatures climb, metabolic and developmental schedules accelerate, potentially reducing the ability to compensate through behavior and diet.
To test how far compensation can go, the team collected tadpoles from the Sintra Mountains and reared them under controlled temperature regimes with different feeding conditions. They then tracked feeding behavior, development time, body size at emergence, and indicators of nutrient processing.
The results show a clear behavioral response to warming. At lower temperatures, tadpoles incorporated a higher proportion of animal-derived food. At higher temperatures, they increased the fraction of plant material in their diet and elevated overall feeding rates—an attempt to offset the consequences of faster metabolism.
However, the strategy weakened progressively as temperatures continued to rise. In other words, tadpoles could adjust their diet, but physiological limits constrained how effectively that adjustment could protect development.
Thermal effects on development were dramatic. Tadpoles raised at 20°C completed the larval stage in about 30 days, compared with roughly 177 days at 12°C. Yet faster growth carried a fitness cost: warm-reared animals emerged smaller and in poorer physical condition.
Beyond growth, warming altered the elemental composition of amphibian tissues. This suggests climate change may affect how organisms store and allocate nutrients, not just how quickly they grow.
The study’s ecological implications extend beyond amphibians. Changes in tissue composition can influence the energetic value of prey for predators and reshape food-web dynamics, potentially altering interactions among aquatic cold-blooded species.
Finally, the authors argue that conservation should consider “thermal refuges.” Preserving cooler microhabitats within wetlands and freshwater systems could help buffer vulnerable life stages and improve survival prospects as Mediterranean temperatures intensify.
Subject of Research: Climate change effects on tadpole diet and physiology (Iberian spined toad, Bufo spinosus)
Article Title: Climate change is forcing amphibians to change their diet – but they can only adapt so far
News Publication Date: 14-Jul-2026
Web References: http://dx.doi.org/10.1038/s41598-026-55894-y
References: Nature
Image Credits:
Keywords: amphibians, tadpoles, climate warming, diet shift, physiological limits, developmental speed, nutrient composition, food webs, conservation, Mediterranean wetlands
