What hibernating toads tell us about climate
24-year study of spring emergence of Fowler鈥檚 Toads creates model for predicting climate-change effects
The ability to predict when toads come out of hibernation in southern Canada could provide valuable insights into the future effects of climate change on a range of animals and plants.
91社区 professor David M. Green of the Redpath Museum and his students have been studying Fowler鈥檚 Toads on the shore of Lake Erie at Long Point, Ontario, for over 24 consecutive years. Green鈥檚 focus? To use weather records to predict the springtime emergence of toads from their annual eight-month hibernation 鈥� and, by doing so, determine if a warming climate is changing the toads鈥� behaviour.
Timing is everything
Green found that the toads鈥� timing can be predicted based on environmental conditions well before the bumpy-skinned amphibians actually wake up.
鈥淭he toads are buried up to a meter deep in the sand. What drives them to come up is when the sand below them becomes colder than the sand above,鈥� explains Green. 鈥淵ear after year, on average, this has been getting earlier and earlier.鈥澛�
The model Green has developed could have broader applications, he says.聽 On the grander scale, if this approach applies to other animals and plants, too, we could generate some powerful information about what is to come as the climate warms.
You never know, it might be useful
The long-running project stemmed, somewhat inadvertently, from Green鈥檚 PhD research into the interbreeding between Fowler's and American Toads. 聽When he became a 91社区 professor, Green continued to study the toads鈥� behaviour, 聽 鈥淏ecause I needed to be at the scene for the start of the toads鈥� breeding season, I began to note when the toads came out of hibernation,鈥� he says. 鈥淲hile I didn鈥檛 set out to study climate change 25 years ago, the data I collected turned out to be far more valuable and interesting then I could have imagined!鈥�
During the nearly quarter-century that Green has been studying toads in the field at night, he鈥檚 encountered his share of hardships. Once, his car got stuck in a sand drift, forcing him to 鈥渨alk six kilometres with leaky boots with only a failing headlamp to get home," he recalls. 聽But the painstaking observations have made possible the model that now enables him to predict the toads鈥� springtime emergence.
Going forward
And the work continues. To test his predictions and make them more precise, Green now has probes in the dunes at Long Point that are recording temperatures underground every 30 minutes. 鈥淲hat the temperature does and what the toads do should match,鈥� Green says. 鈥淲e can also apply this information to investigate when other organisms living on, and in, the dunes wake up in spring.鈥�
听听
"Amphibian breeding phenology trends under climate change: predicting the past to forecast the future" David M. Green, Global Change Biology
This work was supported by NSERC Canada, the Canadian Wildlife Service, World Wildlife Fund Canada, the Ontario Ministry of Natural Resources and Forestry, Wildlife Preservation Canada, and the Canadian Wildlife Federation.
