Romer's Tree Frog

Inset: calling male

Description: A tiny frog, with an average snout-vent length of 1.5 cm, but females may reach a maximum of 2.5 cm. Is Hong Kong's, and indeed on of the world's, tiniest amphibians. Body tan brown above, with an X-like marking on the dorsum. This marking is made up of two crooked black lines, sometimes but not always meeting medially, and often leading to a chevron marking posteriorly. Skin peppered with fine granules. Snout rather pointed. Lips spotted with brown. A dark bar between the eyes, extending to the eyelids. A distinct fold extends from eye to foreleg. Underside white. Hind legs long and slender, irregularly barred with brown-to-black crossbands. Small suction discs on all digits.

Habits and habitat: Prefers to sit on low bushes and grasses or even on the bare ground. Strictly nocturnal. Although this species was thought to be threatened, recent survey has shown that there are a number of large populations on Lanta and Lamma islands. Its habitat is usually well-wooded flat areas near a small stream or other water source convenient for breeding. These areas are frequently vulnerable to development, so that the real threat is destruction of its fragmented habitat.

Diet: Adults feed on termites, small insects such as crickets and spiders.

Reproduction: Breeds in shallow water from early March to September. The male has a characteristic shrill staccato call. The female glues up to 120 eggs on to submerged plant debris, stones or vegetation. Tadpoles tiny, brownish in colour. In captivity require 4 to 6 weeks to metamorphose.

Distribution: A frog unique to Hong Kong. Seems to be restricted to four islands, and so far no naturally occurring population has been found on Hong Kong Island or the mainland New Territories. First discovered on Lamma Island in 1952 by J. D. Romer. Was observed intermittently until 1953 when it seemed to have disappeared. In May 1984 was rediscovered in caves near Sok Kwu Wan on Lamma Island. Since then has also been found on Lantau, Po Toi and Chek Lap Kok islands. Threatened by the construction of the new airport on Chek Lap Kok, part of that population was salvaged, bred in captivity and relocated in various parts of the New Territories and Hong Kong Island.

Diagnostic features: X-marking on its back; head small, snout triangular but blunt; hind legs with black bars; digits with suction discs.