FAQs about frogs and toads: dead frogs/toads

It's common to find dead frogs after breeding (Judy Dowling)

WILDLIFE INFORMATION SERVICE

Frequently Asked Questions about... frogs and toads:

I have found dead frogs / toads, what's going on?

Depending on the time of year there could be several explanations for why amphibians may be found dead in gardens.

Winter

In particularly heavy winters, when ice forms over the pond for prolonged periods, frogs may suffer from 'winterkill'. Essentially, the ice forms a barrier which stops toxic gases (naturally caused by decaying pond detritus) escaping from the pond. In some ponds this can kill common frogs, males of which may choose to lie dormant on the bottom of the pond over winter. You can reduce the chances of winterkill by leaving a floating object, like a ball, in the pond which can be removed after ice has formed. This leaves a hole through which gases can escape. Alternatively, use a pan of hot water placed on the ice to melt a hole. Never pour on hot water - this can lead to animals within the pond suffering from temperature shock - or use salt or chemicals; do not smash the ice as this can damage the pond liner and the pond life.

Amphibians found away from the pond have probably been caught out by a sudden change in weather or have been disturbed by a predator.

Spring

It can be common for amphibians to die naturally after breeding has taken place, sometimes in quite large numbers. Spawning requires a great deal of energy and such exertions can leave amphibians lethargic and more open to predation or natural diseases. Animals that are known to prey on breeding amphibians (particularly frogs and toads) include: foxes, cats, mink, stoats, otters and rats.

Female common frogs and common toads can occasionally become suffocated by males during spawning time. Though distressing to observe, this is a completely natural phenomenon; you should not attempt to separate 'mating balls' as this can damage the animals legs.

During spring amphibians make migrations to breeding ponds, sometimes moving up to half a mile or more. Roads pose a particular problem in some areas where they interrupt migration routes, and dead amphibians, particularly toads, on roads can be a common sight - see our Toads on Roads campaign. Please inform us of sites where you have seen this taking place.

Summer

In particularly hot summers, exposed amphibians can die from dehydration (desiccation). This is a particular threat to froglets that have just left the pond. To avoid this happening make sure there is plenty of shade and shelter provided by plants around the edge of the pond.

If you have found dead froglets in the pond itself then it's likely that they have been unable to get out of the water. When tadpoles metamorphose into froglets they are reliant on breathing air and they are particularly susceptible to drowning at this life-stage. To avoid this happening create gently sloping sides to the pond and areas where it's easy for animals (including small mammals who may fall in by accident) to leave the water.

In adult amphibians, diseases can be common at this time of year. If you have found large numbers of dead frogs that are very thin and were lethargic before death, please get in touch and help our research into amphibian diseases.

More information:

Identifying amphibians. >>>

Amphibian diseases. >>>

Common Toads and Roads >>>

Dragons in your Garden. >>>