A new species of rock-dwelling hylid frog (Anura:Hylidae) from the eastern Kimberley region of Western Australia

Abstract

Australia's documented frog diversity slowly continues to grow owing to genetic tests for cryptic species and ongoing exploration of remote regions. Recent collecting trips in Western Australia's east Kimberley region resulted in the discovery of a new rock-dwelling hylid frog, Litoria staccato sp. nov. The new species is closely related to the much more widely distributed L. coplandi, which also breeds in the same rocky creeks. Litoria staccato sp. nov. is a small to moderate-sized frog characterised from co-occuring species by a combination of a moderately pointed snout, expanded terminal discs, half-webbed toes and a mottled appearance with variable colouration (reddish brown, grey or beige). The advertisement call consists of a rapid burst of irregularly-spaced notes, followed by groups of softer calls comprised of single or complex notes. Compared to L. coplandi, L. staccato sp. nov. is slightly smaller, has reduced webbing between the toes, different colouration and pattern (including diffuse vertebral and dorsolateral stripes), reduced glandular tissue at the angle of the jaw and a highly divergent call. Tadpoles show some adaptations to stream-living but also have body shape affinities associated with ground hylid pond-dwelling types such as L. inermis. The new species has only been found near Wyndham in the far north of Western Australia, and no specimens have been detected in existing museum collections indicating a restricted distribution. Owing to its remoteness and complex geology, the Kimberley region may hold other undiscovered rock-dwelling species with small natural ranges.