AMPHIBIAN DECLINES IN VENEZUELA (UPDATE)

Cesar Luis Barrio Amorós  

I recently reported the introduction of Rana catesbeiana in Venezuela (Barrio Amorós, 2001. Froglog 47;  http://www2.open.ac.uk/biology/froglog/FROGLOG47-3.html), BDG Newsletter No. 44, December 2001.  The original location is a lagoon near La Carbonera, Mérida state, in the Venezuelan Andes at 2000 m.
We believe that this introduction was made 2 or 3 years ago (possibly a little more), and actually the frogs have spread into close lagoons directly affecting endemic species such as Hyla meridensis.  The population has increased since the first sighting, one and a half years ago from anecdotal specimens to thousands.
We advised the Ministerio de Ambiente in order to start an extermination programme but we have no ideas for any working methodology.  We have tried fishing tadpoles with nets, shooting adults, etc but with minimal success.
We ask if any of you have any ideas or know of any successful extermination programmes that we can implement, or know of anyone with experience in this field, I would appreciate your help.