Frogs and other animals that usually hibernate in winter may be very weak by spring because of this winter's balmy temperatures, says an Ottawa researcher.

Frogs usually spend the winter frozen in the mud, hibernating to conserve energy.
(CBC)

Professor Ken Storey, who studies hibernation, at Carleton University's department of biochemistry, says the spring-like weather is fooling frogs into hopping around and singing for mates when they should be frozen in the mud, conserving energy.

"Now it's so warm they've actually come out and they're calling, thinking it's spring," Storey said. "Couldn't be wronger, unfortunately."

Hibernation or sleep?

In winter, many creatures go into a very energy-efficient state where their heart rate, the activity of their other organs and the chemical processes in their bodies slow dramatically. That way, they can conserve energy while their food sources aren't available. In mammals, birds, reptiles and amphibians, this is called hibernation. In insects and snails, it's called winter estivation or diapause. Sleep is a different state where those dramatic changes in energy use don't happen.

Storey said such animals store just enough fuel to make it through the year's coldest months in an energy-efficient state of suspended animation.

At this time of year there is no food to replace the stores they quickly burn up when they are out and about, which will probably leave them skinny and weak come spring.

"What we suspect is going to happen is that as springtime comes, these animals will have run out of fuels and they'll either die, they'll not be able to reproduce, or they will have some other catastrophic event," said Storey, who puts animals such as frogs, snails and insects in his laboratory's fridge in order to study how they slow down their metabolisms over the winter.

Carleton University professor Ken Storey says groundhogs and bears are hibernating just fine despite the green grass and rushing water this January.
(CBC)

The green grass and the rushing water in much of eastern Canada this January aren't waking all animals that usually hibernate through the winter.

Storey said groundhogs are deep underground where temperatures stay more constant, and bears use sunlight and thirst, not warm temperatures, as signals that it's springtime.

This year's warm weather has been partly blamed on El Nino, an abnormal system of warm currents in the Pacific Ocean, but global warming could create more warm winters in the future.

Storey said studying the animals that come out of hibernation this year will help researchers predict how they will cope with longer-term climate change.

"If animals are severely impacted by the little bit of global warming that's occurring now or by one El Nino," Storey said, "we'll know more about how the population structures will change over the next 20 to 40 years."