Does the bell toll for endangered frogs?

Warning bells are being sounded for the future of three species of large Australian frogs, including the endangered Green and Golden Bell Frog, once widespread in Sydney and in coastal areas of NSW.

The biology and conservation of the three bell frog species will be the focus of a conference at the Australian Museum in Sydney this weekend (March 18-19).

One of the three organisers, Dr Ross Goldingay, of Southern Cross University, said the Green and Golden Bell Frog and the Southern Bell Frog were endangered species, while the Tablelands Bell Frog had not been recorded since the 1970s.

"The Tablelands Bell Frog is now believed extinct and this should serve as a warning bell for any complacency in conserving the other two Bell Frog species," Dr Goldingay said.

"The Green and Golden Bell Frog used to be widespread throughout NSW but now it's only found at about 40 sites. In Sydney the frogs used to be so common that they were collected for university dissection and as food for pet snakes."

Dr Goldingay said the frog became the unofficial mascot for the Sydney Olympics after a large population was found in a brick-pit within Sydney Olympic Park.

"Consequently, wetland habitat was created there for the frog and it is now believed to be the largest population of this species in NSW. Habitat for the species has also been created at a number of other sites including in a housing estate near Bulli to protect a small population found there," he said.

"Throughout NSW, this species has lost a lot of habitat and a lot of sites now also contain the 'plague minnow', a fish introduced in the 1920s for mosquito control. The minnow has been implicated in having an adverse effect on the frog's populations."

The bell frog species have mottled green and brown colouring and are quite distinct from green tree frogs. The name is a bit obscure but may have come from the shape of the frog, which is similar to a bell when viewed from above.

Dr Goldingay said the conference would bring together the research conducted over the last 10 years and look at ways of preventing the further decline of the two remaining species.

The national conference is being jointly organised by Dr Goldingay, Dr Graham Pyke, from the Australian Museum and Dr Will Osbourne, University of Canberra. It is being held at the Australian Museum on 18 March and at Newington Armory at Sydney Olympic Park on 19 March, and will include a tour of the wetland habitat at Sydney Olympic Park created for the Green and Golden Bell Frog.

Photo caption: The Green and Golden Bell Frog was once common in Sydney and coastal areas of NSW. Photo by: Ross Goldingay, Southern Cross University.