Winter has long served as a season of stillness, a biological pause, for hibernating animals. When that pause disappears, the consequences may be harder to detect than shifting seasons or changing behavior. New research suggests warming winters are damaging the DNA of common wall lizards.
What's happening?
A study, which was led by researchers at Bangor University, examined how winter warming affects ectotherms. The animals, which are like lizards, rely on external heat sources to regulate their body temperature.
The team looked at common wall lizards, exposing them to altered winter conditions during their normal hibernation period. During a period of three-and-a-half months, the animals experienced one of three scenarios: a typical cold winter, a constantly mild winter, or fluctuating winter temperatures.
Researchers tracked activity levels, body condition, and oxidative stress, which occurs when free radicals outpace antioxidants in the body and begin damaging cells and DNA. In humans, oxidative stress has been linked to diseases such as cancer, Parkinson's, and Alzheimer's. It is associated with aging, reduced fertility, and lower survival rates in animals.
The study found that lizards exposed to constant mild winter conditions became significantly more active during hibernation and showed a trend toward increased DNA damage due to oxidative stress. However, researchers found that fluctuating temperatures did not have the same effect.
As lead author Miary Raselimanana explained, "Winter is warming faster than summer, posing a substantial threat to hibernating ectotherms, whose physiology depends directly on environmental conditions."
TCD Picks » Upway Spotlight
💡Upway makes it easy to find discounts of up to 60% on premium e-bike brands
Why are these changing habits concerning?
When food is scarce, hibernation helps animals conserve energy. Warmer winters disrupt that rest, leading to the possibility that animals will struggle to replace that energy. Ultimately, this damage can accumulate, reducing lifespan and reproductive success.
Those hidden dangers matter beyond reptiles. Ectotherms play essential roles in ecosystems that support agriculture, control pests, and maintain biodiversity. When these systems are destabilized, the impacts can have wide-ranging effects, threatening food security and environmental resilience that human communities depend on.
The research also exposes a gap in how environmental risks are assessed. "The specific warming patterns most disruptive to hibernation, their effects on winter activity, and the subsequent physiological consequences are poorly understood," said Raselimanana.
What's being done about it?
The researchers emphasize that behavior alone doesn't tell the full story.
TCD Picks » Quince Spotlight
💡These best-sellers from Quince deliver affordable, sustainable luxury for all
|
Do you think America does a good job of protecting its natural beauty? Click your choice to see results and speak your mind. |
Definitely 👍 "Overall, our findings suggest resilience in the behavior of common wall lizards to moderate winter warming," said study supervisor Dr. Kirsty Macleod. "However, hidden costs at a molecular level could emerge under sustained mild conditions."
Going forward, the research team is calling for future research and predictive models to account for subtle physiological stress, not just visible changes in behavior or population size. That insight can help conservationists, planners, and policymakers better anticipate which species are most at risk as winters continue to warm.
The main takeaway is less about lizards specifically and more about what they signal. Small shifts in seasonal patterns can undermine biological systems that took millennia to evolve. This can slow progress toward healthier, more resilient environments for everyone.
Get TCD's free newsletters for easy tips to save more, waste less, and make smarter choices — and earn up to $5,000 toward clean upgrades in TCD's exclusive Rewards Club.
Cool Picks
