Can the Green and Golden Bell Frog be saved from extinction?

They wear the green and gold proudly, are great athletes that can swim and climb very well, and love to sunbathe in the middle of the day - but sadly, their days might be numbered.

Green and Golden Bell Frogs, like many other Australian frog species, are in crisis, and like their relatives the world over, are disappearing at a rate never seen before. New research has revealed that this species has lost almost one-quarter of its population in the last 12 years.

This research is contained in a special edition of the recently published journal, the Australian Zoologist. The senior editor of this new publication is leading frog researcher Dr Ross Goldingay, from the School of Environmental Science and Management at Southern Cross University.

The publication brings together a wealth of research not only on the endangered Green and Golden Bell Frog, but also the Southern Bell Frog, whose numbers have also dwindled alarmingly in recent years. Dr Goldingay said habitat loss and degradation, introduced fish and an introduced frog fungus are the major causes of the decline of these two species.

Dr Goldingay’s contribution to the journal, ‘Ecology and Conservation of Australian Bell Frogs’, brings together a comprehensive and up-to-date account of research on these two bell frog species. Many of the papers in this book provide descriptions of projects that specifically address the management and conservation requirements of these frogs. Two papers describe projects that have been instrumental in educating the public about bell frog conservation and have won environmental awards.

The decline of the Green and Golden Bell Frog came to the attention of biologists in the early 1990s. Historically, this species was abundant at many locations around Sydney and coastal NSW but it disappeared precipitously from much of its former range in just two decades or less. 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.

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

This discovery initially posed a quandary for some proposed development but the frog became a key planning parameter that has shaped how the Park looks and is managed today. Several papers in this new publication describe the planning process at Sydney Olympic Park and current management of the frog population there.

“This effort to re-establish the Green and Golden Bell Frog is arguably one of the largest habitat construction projects ever undertaken for an endangered amphibian in Australia,” Dr Goldingay said.

Dr Goldingay said that despite much work having been completed on the two bell frog species, he is not overly optimistic that each will be conserved in the long run.

“Success in conserving them will only be achieved through the on-going dedication of researchers and volunteers, and with a considerable amount of commitment from government agencies, private industry and landholders, perhaps beyond what we have seen to date,” he said.

“The apparent extinction of the related Yellow-spotted Bell Frog from the southern, central and northern tablelands of NSW in the 1980s provides a sobering reminder of what failure looks like.”

Dr Goldingay said he hoped that the collected papers in this publication would enhance the conservation prospects of the Green and Golden Bell Frog and Southern Bell Frog over future decades and that this work would also inform conservation directed at other frog species.

“I strongly believe there are many valuable insights in this publication for conserving frogs in general. Perhaps a key lesson from the decline of the bell frog species is that we should not take local abundance too much for granted,” he said.

Green and Golden Bell Frog facts

The Green and Golden Bell Frog is one of the few frogs known to be active by day and appears to enjoy basking in direct sunlight.

The Green and Golden Bell Frog has disappeared from the northern part of its range between Grafton and Byron Bay.

It has smooth skin, usually green, with a variable pattern of golden brown blotches. It has a creamy-gold stripe along the side of the body, from the eye to the hind legs. The inside of the thighs are distinctly coloured in turquoise-blue. Females grow to an adult size of approximately 9 cm in length; males are smaller, rarely exceeding 8 cm.

The frogs live in urban and rural swamps and ponds and have a distinctive three-part call. Males usually call while floating in open water. The call is a long growl of several seconds’ duration followed by a series of short grunts - ‘cr-a-a-aw-a-a-awk, cra-a-a-awk, crok crok’. A similar call made by the Southern Bell Frog gives rise to the common name it is given in Victoria of the Growling Grass Frog.

Photo: The Green and Golden Bell Frog which has already disappeared from the northern part of its range between Grafton and Byron Bay is under threat of total extinction. (High resolution image available on request.)