Tadpoles in October?

dogmatix

I spotted a small number of Tadpoles in a small pond in the Vale of Clara yesterday. They where about the size of my little fingernail. I never thought there would still be tadpoles hanging about this late in the year - I always assumed they would be frogs by June or July or else some animals lunch.

Any ideas as to why they have been so slow in developing or did some frog just spawn very late in the year? Will they survive the winter (the pond has very soft and deep sediment which looks like it might provide some comfy lodgings for the winter ahead). Do they hibernate?

Alun

This has come up on here before I think, so I Googled a bit and came up with this from a question someone asked on the Guardian website ...

I still have tadpoles in my garden pond. How unusual is this and will they survive the winter?

For the past few years we have been researching the phenomenon Jane Astbury describes and have received a number of similar reports from members of the public. We have found that, within the UK at least, common frogs over- wintering as tadpoles is really quite widespread, stretching from Kent and Cornwall in the south to Aberdeen in the north.

Our research has shown that it is unlikely that the over-wintering tadpoles have been unable to complete their development in the summer and have become trapped in their ponds; rather, they are choosing to remain in the ponds.

The tadpoles in many of the ponds both in the field and the laboratory survived the winter perfectly well, and actually completed metamorphosis in the early spring. They did so at a much larger size than tadpoles that had completed development and metamorphosed in their first summer.

Therefore, some individuals may be taking advantage of the milder winter temperatures, from global warming, to become larger frogs.

Dr Patrick T Walsh (University of Edinburgh) and Prof Roger Downie (University of Glasgow)

recedite

Water at the bottom of a deep pond will remain at around + 4 degrees C, because a unique property of water is that it is most dense at thet temp; hence the learned professors are incorrect in saying;

Therefore, some individuals may be taking advantage of the milder winter temperatures, from global warming, to become larger frogs

If anything, it is a longstanding evolutionary strategy to deal with colder winters. A gill equipped tadpole hibernating at a steady 4 degrees has a better chance than either a froglet burrowed down a few centimetres on land, or a froglet in water. Nature often "hedges her bets" in having more than one survival strategy within a species.