As the cold snap continues, Froglife -a UK wildlife charity for amphibians and reptiles- is encouraging pond-owners to consider ensuring garden ponds don’t stay iced over for too long.
Common Frogs Rana temporaria often lie dormant on the bottom of garden ponds during winter, but when ponds ice over for a sustained period they can suffocate on the noxious gases that build up in the water. In some winters, many frogs can die from this phenomenon, often termed ‘winterkill’.
Winterkill is a natural killer of frogs in cold winters. Many garden owners choose to take steps to reduce winter mortality and keep their local frog populations thriving.
The solution is simple, say Froglife: “To stop winterkill happening in your pond simply ensure that there is a hole in the ice for pond gases to escape. You can make a hole by leaving a plastic ball in the pond overnight, and removing it in the morning when the pond surface is frozen. Another idea is to leave a pan of hot water on the ice surface, and allow the base of the pan melt a hole.”
“Importantly though, never pour hot water on the pond ice, and don’t add chemicals (particularly salt), or try to shatter the ice. All of these methods can cause serious damage to pond inhabitants,” said Lucy Benyon, Froglife’s Wildlife Information Officer.
In many parts of the UK, a number of amphibian species (frogs, toads, newts) are facing serious declines, largely because of the loss of ponds in the wider countryside. Urban areas have provided a crucial refuge for some species, thanks to an increase in the number of garden ponds in the last thirty years.