FrogLog 103 PDF here - Amphibian Specialist Group

Ex-situ Amphibian Conservation in Southern Africa
By Ian Visser
Since the inception of its Amphibian
Conservation Project (ACP) in
2006 the Johannesburg Zoo has
taken on an increasingly important role
in the relatively new field of South African
amphibian conservation.
The ACP was initiated six years ago as part
of the Zoo’s ongoing effort to increase its
overall conservation and research effort,
particularly with regard to supporting
off-site conservation programs for indigenous
threatened animal species. Along
with other projects, such as those for the
African ground hornbill and the Wattled
crane, the ACP provides staff members
with an opportunity to get directly involved
with a conservation program and
broaden the scope of their normal duties
as Zoo staff. Special focus is given to the
improvement of husbandry skills but exposure
to all aspects of the management
of such conservation projects is also an
important consideration.
As the program developed it also demonstrated
its usefulness with regard to
establishing valuable links with other
research and conservation institutions, in addition to providing
a very useful tool for public education. Under the auspices of the
African Association of Zoos and Aquaria (PAAZAB) successful partnerships
in support of this project have been established between
the Johannesburg Zoo, Ezemvelo Kwazulu Natal (EKZN) Wildlife,
the National Research Foundation (NRF), the National Zoological
Gardens (NZG) and North-West University (NWU). Progress
to date is also providing a model for future similar collaborations
regarding amphibian conservation in Southern Africa.
Very little ex-situ husbandry research has been carried out on our
indigenous frog species to date. At the project’s inception the decision
was therefore made to initiate research aimed at three threatened
species of amphibians, with a view towards selecting one or
more of these for further conservation research when the project
was judged to have progressed to a satisfactory point. The species
chosen were the Western leopard toad Amietophrynus pantherinus,
Table mountain ghost frog Heleophryne rosei and Pickersgill’s
reed frog Hyperolius pickersgilli. Once species that had the potential
to benefit most from ex-situ conservation work were selected,
a congeneric (analogous) species was identified for each, and collection
trips for these species soon resulted in the beginning of the
Zoo’s first indigenous amphibian husbandry program.
Mr. Timothy Netsianda, Amphibian Keeper at the Johannesburg
Zoo, with a Giant bullfrog Pyxicephalus adspersus. Photo: Ian
Visser.
The Natal cascade frog Hadromophryne
natalensis was chosen as a congeneric
species for the Table mountain ghost
frog. As both frog species live in cold water
streams the larval development phase
takes over a year. Results with the Natal
cascade frog were correspondingly slow
in coming, but within five years research
had progressed to the stage that gravid
females were produced from tadpoles
collected during the course of the program,
although breeding success eludes
us as yet. Due to the paucity of adult
Table mountain ghost frogs to be found
in the wild population, as well as other
relevant considerations reached after
consultation with the Cape conservation
authorities, the decision was made to
discontinue plans for the target species,
with the efforts of in-situ conservation
efforts being focused upon further research
and monitoring as well as ongoing
work being carried out to re-establish
the natural flow of the mountain streams
upon which this species depends for its
existence. Husbandry research will however
continue to be carried out with the
Natal cascade frog in order to further our
knowledge of this group of amphibians and their breeding behavior
for future reference.
The Guttural toad Amietophrynus gutturalis provided a congeneric
species upon which to base research for the Leopard toad.
Although the Guttural toad is abundant over much of South Africa,
and breeds readily in just about any suitable water body available,
it took four years before we were able to observe spawning in our
captive population. Once Guttural toads begin breeding they are
very prolific, and for the past two seasons a high hatch rate has produced
several thousand tadpoles, some of which were allowed to
Curator of Fish, Reptiles and Amphibians at the Johannesburg Zoo.
Project Coordinator for an ex-situ conservation and research project for
Pickersgill’s reed frog.
FrogLog 20 (4) | Issue number 103 (July 2012) | 17