The moor frog (Rana arvalis) prefers wetland habitats and is commonly found in coastal meadows and sea bays. The species is difficult to distinguish and its distribution is largely unknown. In Helsinki, it is found in Vanhankaupunginlahti, Laajasalo, Uutela and the areas annexed from Sipoo.
Its spawning season is in early May, slightly later than the European common frog’s. The moor frog’s spawning call is bubbly, like an empty bottle being submerged. The European common frog’s spawning call, on the other hand, is a low croak. The spawning call is the most distinguishing characteristic of the moor frog.
Without the spawning call, identification requires precision: the moor frog is smaller than the common frog, its stomach is usually uniformly light, and the so-called metatarsal tubercle near the inner rear toe is large and hard. The moor frog is a protected species.
This dead frog was identified as a moor frog, photo Eero Haapanen.