Predicting the date of frog emergence in Devon
The first frog spawn (already one to two days old) of 1999 was seen in a garden pond in Crediton, Devon, on 18th January. Within a few days of this date, Common Frogs Rana temporaria were spawning over a wide area of mid-Devon. The trigger for bringing frogs out of hibernation to return to their breeding ponds to mate and lay spawn is uncertain. Increasing day-length and temperature would be expected to have an influence.