Abstract

In 1999, biologists discovered fecal material that provided evidence for the existence of a large lizard of the genus Gallotia on the island of La Gomera, Canary Islands. The existence of Gallotia, a genus restricted to the Canary Islands, on La Gomera was known from fossil records but was considered to have been long extinct. Following this discovery, an exhaustive search of the island from June to September 1999 led to the capture of six animals (two male, four females) from the Risco de La Merica in the Valle Gran Rey. The decision to remove these animals from the wild was based upon fears of extinction due to the increasing feral cat population. Canarian Gallotia lizards comprise of G. galloti (La Palma, Tenerife, El Hierro, La Gomera, Las Palmas), G. intermedia (La Palma, Tenerife), G. stehlini (Gran Canaria, Fuerteventura), G. atlantica (Gran Canaria, Lanzarote and Fuertaventura), and G. simonyi madachoi (El Hierro). The taxonomic classification of this new lizard, Gallotia simonyi gomerana, is pending official sanction. These lizards are listed in CITES appendix 1. Initially all lizards were maintained in individual vivaria within secure government offices on the island of Tenerife. Three animals (one male, two females) were subsequently moved to a purpose-built, outdoor breeding facility on the island of La Gomera. The Canarian authorities have considerable experience of maintaining and breeding Gallotia lizards from various islands and similar husbandry and nutritional practices were adopted for these animals.

In April 2000, one male developed hind limb paresis and the authors were requested by the Spanish Government to examine and assess the six specimens. The health assessments included husbandry and nutritional evaluations, physical examinations (including weight and length measurements), hematology, biochemistry, fecal microbiology and microscopy, and survey radiographs where electricity and equipment were available.

All the animals were microchipped and treated with oxfendazole and metronidazole due to the heavy burdens of unidentified nematodes and Trichomonas sp. protozoa on the fecal examination. The male with hind limb paresis was diagnosed with a spinal lesion at L8–L9. Despite initial improvement, the lizard died several months later. Post-mortem examination indicated severe mycotic hepatitis, 1 cm diameter mycotic granuloma over T7–T8 with associated osteomyelitis of the spine. The remaining animals were considered clinically healthy although minor improvements in captive management were recommended.

It is hoped that through continued cooperation between the Canarian Government, conservationists and veterinarians, a successful breeding program will increase the captive population and facilitate reintroduction to the wild once circumstances become more conducive to survival. Such plans have proved successful for other Gallotia species in the Canary Islands.

Acknowledgments

Thanks to J.A. Mateo, J. Pether, J.L. Rodriguez Luengo, Dr. A. Martínez Silvestre, J. Orós, Dr. L. Silveira, P. Calabuig and P. Machin, M. Brampton, Dr. N. Vaira, Dr. L. Martinez Segurado, J de Urioste, D. Shepherd and Professor J. Cooper for their contribution to the project.