A Puddle of Tadpoles

Rana temporaria tadpole

There is a forest, about 10 miles from Cork city. Its a commercially planted one, Sitka Spruce and Japanese Larch, with a border of Beech. The forest is bisected by a walkway, which acted as an access road when part of the forest was harvested some two years ago. The heavy machinery used in the harvest left depressions in the road which the recent rain has turned into dirty, shallow puddles – puddles that are home to a cloud of tadpoles.

A puddle of tadpoles

The puddles were at most 20 cm at their deepest parts, but the Common Frog (Rana temporaria) tadpoles were most visible at depths of 5 cm or less. It does seem odd that adult frogs would spawn in such shallow, temporary water source but not at all uncommon (as reported last year on this blog, for example) and can often lead to catastrophic losses (1). However the tadpoles are able to respond to this stress by speeding up their development, metamorphising faster when posed with the problem of pond (or in this case puddle) drying (1).

Rana temporaria tadpole

References:

1. Laurila and Kujasalo, 1999. Journal of Animal Ecology 68 pp. 1123–1132