Rising Temperatures Affect Frog Reproduction

Climate change is not only driving extreme weather and rising global temperatures. A new study suggests it is also reshaping how wildlife reproduces — altering the mating calls of frogs in ways that could disrupt breeding patterns.

Researchers at the University of California, Davis found that increasing air and water temperatures directly change the characteristics of mating calls in the Sierran treefrog. Those temperature-driven changes influence when females decide to lay eggs, offering new insight into how global warming may affect amphibian reproduction.

“Frog calls are highly temperature dependent,” said Julianne Pekny, the study’s lead author and a conservation scientist. “As ponds warm in the spring, male calls shift from slow and lethargic to faster and more energetic. Females respond to those changes.”

The findings, published in a journal of the Ecological Society of America, February 2026 add to growing evidence that climate change is influencing not just when animals breed, but the communication signals that guide reproductive timing.

How Rising Temperatures Affect Frog Reproduction

Male frogs typically arrive first at breeding ponds in early spring and begin calling to attract females. But the study shows that water temperature significantly shapes the rhythm and intensity of those calls.

In colder water, male calls are slower and less forceful. As temperatures rise, the calls become quicker and more energetic. Researchers say this shift is more than a simple physiological response — it serves as an ecological signal.

According to Brian Todd, a co-author of the study and professor of wildlife biology, female frogs appear to use call quality as an indicator of environmental readiness.

“For males, arriving early provides a competitive advantage,” Todd said. “But for females, timing is critical. They need to ensure that water temperatures are warm enough for eggs and tadpoles to survive.”

In other words, mating calls function not only as sexual signals but also as cues about habitat conditions. If climate change causes temperatures to fluctuate unpredictably or warm earlier than usual, the synchronization between male signaling and female reproductive readiness could be disrupted.

Climate Change and the Growing Threat to Amphibians

Amphibians are among the most vulnerable vertebrates on Earth. Globally, roughly 41 percent of amphibian species are considered threatened with extinction. Habitat loss, pollution, disease and climate change all contribute to population declines.

The study’s senior author, Eric Post, said the research expands understanding of how climate change affects phenology — the timing of seasonal biological events such as breeding and migration.

“We often study when animals begin breeding,” Post said. “But this research shows that climate change may also influence the communication signals that determine that timing.”

If spring warming arrives earlier or becomes more erratic, frogs may breed under suboptimal conditions. Eggs could be laid before ecosystems are fully ready, or developing tadpoles may face higher risks due to temperature instability.

Subtle Signals of a Warming Planet

For many people, the sound of frogs calling at night marks the arrival of spring. For scientists, subtle changes in the speed and energy of those calls may signal broader ecological shifts linked to global warming.

Pekny said listeners who return to the same pond over several weeks may notice differences in call tempo as temperatures rise. “You can hear the difference,” she said. “Now imagine how females interpret that difference when deciding whether it’s the right time to lay eggs.”

The study underscores that the effects of climate change are not always dramatic or immediately visible. Sometimes they emerge through subtle behavioral shifts — such as a slightly faster mating call echoing across a warming pond.

As global temperatures continue to rise, researchers warn that disruptions to reproductive timing could compound existing threats facing amphibians. For species already under pressure, even small mismatches between environmental conditions and breeding cycles may accelerate population declines.