Temperature, genetic and hydroperiod effects on metamorphosis of brown frogs Rana arvalis and R-temporaria in the field
Time for metamorphosis and metamorph size of moor frogs Rana arvalis and common frogs R. temporaria were measured in 22 ponds for 18 years. Environmental data in these ponds were also measured. Metamorphosis of the frogs took place from the beginning of June to the beginning of August. When both species were found in one pond, the common frogs metamorphosed up to 20 days earlier than the moor frog