Common name: Eungella dayfrog
Scientific name: Taudactylus eungellensis Liem and Hosmer, 1973
Family: Myobatrachidae (Australian water frogs)
Endemicity: Queensland endemic
Conservation status: This species is listed as Endangered in Queensland (Nature Conservation Act 1992) and nationally (Environment Protection and Biodiversity Conservation Act 1999). It is considered a medium priority under the Department of Environment and Heritage Protection Back on Track species prioritisation framework.
The Eungella dayfrog is a small frog, with a somewhat pointed snout. The upper surface of the frog may be yellowish tan to dark brown, with irregular dark brown markings. A broad band crosses the head between the eyes, with two bands behind this. A black band extends from behind the eye to the base of the forearm, and there is a prominent irregular X-shaped marking on the back.
There are cross-bands on the limbs and digits. The throat and abdomen are white or cream-coloured, and the ventral surfaces of the limbs are bright yellow, with or without dark brown spots. The skin is roughened above and the ventral surface is smooth. The fingers and toes have expanded tips, and are broadly fringed but lack webbing. Males have finely greyish rounded nuptial pads like a blister on the back of the hand at the base of the second and third fingers. Males do not possess a vocal sac. The typanum (hearing organ) is hidden.
Male frogs range from 23.8 to 32 mm, and females from 25.5 to 37.11 mm. Weight ranges from 0.8-5 g.
The tadpole is orange brown, with a distinctive V-shaped marking behind the eye, and dark pigment around the base of the tail and upper surface of the tail muscle. The body is oval and the fins clear and narrow, with a rounded tail tip.
Habitat and distribution
The Eungella dayfrog inhabits exposed rocky sections in the splash zones of riffles, cascades and waterfalls of rainforest streams. They may be found under rocks and crevices or in more exposed positions. The tadpoles are bottom-dwellers, inhabiting mid-stream pools or partially connected stream-side pools.
This species is restricted to a small area of the Clarke Range, mid-east Queensland at altitudes of 200-1000 m. It has undergone a rapid and dramatic range contraction, and after a period of apparent absence, has now been located at nine sites within its former distribution. It is found in Eungella National Park.
Life history and behaviour
Calling has been heard during most months of the year with the greatest intensity during spring and summer. The call is a gentle rattling sound barely audible over the sound of rushing water. The Eungella dayfrog is largely diurnally active with calling during the day, though males will call at night. They bask on exposed rocks, and when disturbed escape into the water, remaining submerged on the bottom for some time. Males have been observed communicating by visual cues, which include flicking and waving of legs, head bobbing, and distinctive hops.
This species is a late summer breeder and egg laying occurs from November to May. Females lay 30-50 large (2.2 - 2.6 mm) eggs under rocks in the water. The tadpoles overwinter with metamorphosis occurring between November and January.
The Eungella dayfrog underwent a rapid range contraction in the mid 1980’s. The cause of the population decline remains unknown, but the disease amphibian chytrid fungus disease is strongly suspected.
The biggest risk to the species is now the inherent risk of small numbers of animals in a very small distribution.
The recovery plan for the conservation of stream-dwelling frogs of the Wet Tropics bioregion makes the following management recommendations:
- Monitor sites where species were recorded historically to detect recovery of the species.
- Investigate disease in preserved specimens and other species occupying similar habitat.
- Continue studies on the autecology of this species.
- Train park staff and community volunteers in identification of this species.
- Implement monitoring by park staff of select locations within the national park estate where the species formerly occurred.
Northern Queensland Threatened Frogs Recovery Team. 2001. Recovery plan for the stream-dwelling rainforest frogs of the Eungella region of mid-eastern Queensland 2000–2004. Report to Environment Australia, Canberra. Queensland Parks and Wildlife Service, Brisbane.
Curtis LK, Dennis AJ, McDonald KR, Kyne PM, and Debus SJS. 2012 Queensland’s Threatened Animals, CSIRO, Victoria, Australia.