The Action Plan for Australian Frogs
By
Michael J. Tyler
with the assistance of the Editorial Advisory Committee
Wildlife Australia, April 1997
ISBN 0 642 21400 X
Recovery Outline No. 16: Stuttering Frog
1. Family
Leptodactylidae
2. Scientific Name
Mixophyes balbus
3. English Name
Stuttering Frog
4. Intraspecific taxa:
None.
5. Species survival status
Vulnerable. Considered secure until recently. Recent studies (Mahony 1996) have indicated a decline, particularly from the southern regions of its broad geographic range. The species appears to have specific habitat requirements and these are not fully understood.
6. Former distribution
From East Gippsland in Victoria along the eastern escarpment of the Great Dividing Range and coastal region to north eastern NSW.
7. Current distribution
Recent searches have located the species north of the Hastings River drainage, but numbers have been extremely low and breeding activity was observed on only one occasion in the summer of 1992. The species has not been detected in the State Forests between the Hawkesbury and Hastings Rivers during extensive searching in the warm months of 1991-1992 and again in the spring of 1992. This species was once locally abundant in several of the forests where routine searches have been conducted. Searches from 1987 to 1994 at known sites near Berry, Jamberoo and Gerringong, under ideal conditions, have failed to detect the species
(H. Ehmann pers. comm.). This species has been regularly recorded from Myall River State Forest since February 1993. It has also been recorded from Bulahdelah State Forest in the same period. Searches initiated by State Forests of NSW located this frog in Dampier and Mumbulla State Forests during 1994. Searches in 1995-96 revealed three additional small populations on the south and central coast of NSW (M. Mahony pers. comm.). There are only three records for Victoria and the species has not been seen there for over 14 years.
8. Habitat
Wet forests usually above 100m, predominantly near slow-flowing mountain streams. Also found in moist gullies within areas of dry forest, sometimes utilising very small trickles of water which hardly flow.
9. Reasons for decline
Unknown.
10. Conservation reserves on which species occurs
NSW: Blue Mountains, Morton, Dorrigo, Gibraltar, Washpool, New England and Werrikimbee National Parks. Vic: Coopracambra National Park.
11. Other public lands on which species occurs
NSW: Bielsdown, Bulahdelah, Carrai, Chaelundi, Dampier, Ellis, Forestlands, Hyland, Malara, Marengo, Mumbulla, Myall River, Olney, Strickland, Watagan, Mt Boss, and Wild Cattle Creek State Forests.
12. Other lands on which species occurs
None known.
13. Is knowledge about species adequate for objectives and actions to be defined accurately?
No. While recent research has improved knowledge of the species the environmental factors which limit its distribution and abundance remain unclear.
14. Recovery Plan objectives
14.1. To determine the factors limiting the distribution and abundance, and causing decline.
14.2. To make recommendations for habitat management designed to ensure populations of the species survive.
14.3. To obtain sufficient biological and ecological information to monitor the conservation status, and to enable formulation of appropriate management strategies.
14.4. To maintain populations in all areas of forest where they currently occur.
15. Management actions completed or under way
A 3 year research program directed at the genus Mixophyes, including M. balbus, funded by the Endangered Species Program of Environment Australia and the NSW National Parks and Wildlife Service, has recently been completed by the University of Newcastle (M. Mahony). It consisted of the following actions:
15.1. Field survey to determine distribution and abundance.
15.2. Review of distribution using complete literature search and museum specimens.
15.3. Vegetation and water quality analysis of known sites to be used to model its distribution.
15.4. Ecological studies of selected populations, particularly to investigate reproductive success and recruitment.
15.5. Laboratory studies of tadpole growth and development to assist understanding of environmental requirements of larval stages.
15.6. Studies of genetic variation within and between populations.
15.7. On the basis of the above research a draft recovery plan is being prepared for this species, in conjunction with M. iteratus and M. fleayi, as part of a recovery program for the threatened frogs of Qld and northern NSW (Coordinator: K.R. McDonald, Qld Department of Environment).
15.8. State Forests of NSW are targeting this species in their northern NSW monitoring program. Species profiles and draft species management prescriptions have been jointly prepared by State Forests of NSW and NSW National Parks and Wildlife Service for protection of this species within production forest.
16. Management actions required
16.1. Population monitoring.
16.2. Ecological research including specific habitat requirements, movement patterns, predation, population dynamics, diet, reproductive biology and larval ecology.
16.3. Research into possible causes of decline (disease, ultra-violet radiation, pollutants).
16.4. Investigation of captive breeding potential.
16.5. Training for forest land managers to ensure mitigation of activities carried out in the habitat of the species.
17. Organisations responsible for conservation of species
NSW National Parks and Wildlife Service, Vic. Department of Natural Resources and Environment.
18. Other organisations involved
University of Newcastle (M. Mahony), SA Museum (S. Donnellan), University of Canberra, Frog and Tadpole Study Group of NSW Inc., State Forests of NSW.
19. Can recovery be carried out with existing resources?
No.
A recovery plan is in preparation for M. balbus, M. fleayi and M. iteratus, as part of the recovery program for threatened frogs of Qld and northern NSW. Actions which may be addressed in the plan include monitoring, ecological research, research into causes of decline, captive breeding and habitat management. The estimated cost of implementation is $80K per annum over 5 years (for 3 species).
Total (average cost per species) $133K
References:
Mahony, M. 1996. Draft final report: Great Barred River Frogs Research Plan. Unpublished report to the Australian Nature Conservation Agency, Canberra, and the New South Wales National Parks and Wildlife Service, Hurstville.
Herpetological authorities consulted:
G.R. Gillespie, F. Lemckert, L.C. Llewellyn, M.J. Mahony, K.R. McDonald, P. Robertson.