Amphibians are some of our most primitive land animals to own a backbone. Unfortunately for them one of their primitive traits is an inability to regulate body temperature which means that in the UK they have to take action before it gets freezing cold!
The best way to do this is to hibernate or ‘go dormant’ through the cold months.
Many frogs swim to the bottom of ponds and partially bury themselves in mud. This poses two problems: first, frogs have lungs so when under water they risk drowning, second, if the water freezes solid it will probably kill the frog.
The first issue is solved by the frog getting oxygen and releasing CO2 through its porous skin. this works here when it doesn't normally because the frog’s metabolism has slowed down so much the body doesn’t need much oxygen.
The second problem is avoided by finding a pond deep enough that the ice doesn't reach it.
The alternative to spending winter underwater is to find somewhere suitable on land. Toads and great crested newts favour this option often hiding in compost or burrowing into the ground; I’ve heard stories of people digging in their gardens and finding newts two feet down!
Despite all this effort to stay frost free there are some northern species (not in the UK) that do actually freeze on the outside, but their blood becomes a type of anti-freeze laced with sugars which means the ice only freezes around them and leaves their cells unharmed!
Amazingly clever, these amphibians, for such a ‘primitive’ kingdom.
There are many ways you can help frogs and other amphibians in your garden. Why not check out our Giving Nature a Home site to get you started?