A Winter Frog

December is perhaps not the best time of year to view common frogs in North Yorkshire, however whilst watching a couple of sparrowhawks over the back of the house I noticed movement across the lawn. It was in fact a large female common frog, which appeared to be in good health, on a mission to cross the garden. It is more than likely that she was pushed out of her hibernacula by a localised seepage or flood, with the weather forecast frost free for the next couple of days, she will hopefully seek somewhere better for the remaining months of winter. Female common frogs (and immature animals) unlike many males hibernate terrestrially out of water. They tend to chose small mammal burrows, decaying logs, rubble piles, compost heaps and any other frost free, stable holes or gaps not prone to flooding (i.e. on features like embankments). Although it's not unusual to have breeding frogs as early as December in the south west, it is unusual to see them active here in December. Undoubtedly a result of the mild winter so far. Common frogs like other amphibians do not hibernate in the same way as we see with hedgehogs and dormice but simply take refuge and reduce activity levels. Being cold blooded means they do not have the same energy requirements and need to keep a warm core as mammals nor do they need quite as much fat reserves. In mild winters activity can be almost constant in some individuals, with refuge sought only during snow and ice. Common frogs have even been found with prey remains in their stomach during the winter, indicative of foraging behaviour. Unfortunately the rain was so persistent I could not get a photograph, but still an interesting record.