Literaturdatenbank
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Wiese, C., Hillard, S., & Phillips, M. , The bolson tortoise (gopherus flavomarginatus) breeding program on the turner ranches in new mexico - abstract. Unpublished paper presented at Program and Abstracts of the Tenth Annual Symposium on the Conservation and Biology of Tortoises and Freshwater Turtles.
Added by: Admin (06 Jan 2014 18:23:14 UTC) |
| Resource type: Conference Paper BibTeX citation key: Wiese2012 View all bibliographic details  |
Categories: General Keywords: Gopherus flavomarginatus, Habitat - habitat, Haltung - husbandry, Nordamerika - North America, Schildkröten - turtles + tortoises, Testudinidae Creators: Hillard, Phillips, Wiese Collection: Program and Abstracts of the Tenth Annual Symposium on the Conservation and Biology of Tortoises and Freshwater Turtles |
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| Abstract |
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Testudinidae The Bolson Tortoise (Gopherus flavomarginatus) is the largest of the North American Gopherus species and is native to the Chihuahuan desert of north-central Mexico. The last comprehensive examination of the wild Bolson Tortoise population (which took place about 30 years ago and was performed by Dave Morafka and colleagues) suggested that both Bolson Tortoise habitat and Bolson Tortoise numbers are rapidly declining. It is highly likely that fewer than 10,000 animals (and today perhaps as few as 2,000) remain in the wild. A group of 24 adult captive Bolson Tortoises, collected since 1972 by the late Ariel Appleton, was donated to the Turner Endangered Species Fund (TESF) in 2005 and has been living on the Armendaris Ranch near Truth or Consequences, New Mexico, since the fall of 2006. The goal of TESF’s Bolson Tortoise Project is to use this unique captive population to build independent, viable, free-living populations of the endangered Bolson Tortoise in the US (and possibly Mexico). To determine whether establishing a Bolson Tortoise population this far north in its Pleistocene range is possible, we initially focused on two key questions: (1) Are the New Mexico habitats suitable for Bolson Tortoise growth and fecundity? (2) Can we generate large cohorts of releasable offspring from the captive group? We tracked health, growth and egg production of the captive population since 2006 and found that both juveniles and adults show signs of robust growth in the desert grassland habitat of the northern Chihuahua desert. For example, some juveniles more than doubled their initial shell length in 5 years of living on native forage, and at least one young adult grew 30% in 5 years. Reproductive rates and outputs in the captive population are robust and comparable to those of wild Bolson Tortoises. We developed protocols to maximize hatchling production by recovering eggs from nests or harvesting them by induced oviposition (i.e., oxytocin injection) and placing them in custom-built constant temperature incubators. We currently house ~180 Bolson Tortoise juveniles between the ages of <1 to 6 years in predator-resistant enclosures. Thus, an independent, freeranging Bolson Tortoise population in New Mexico is not out of the question.
Added by: Admin |