Literaturdatenbank
Literaturdatenbank |
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Páez, V. P., Daza, J. M. R., Bock, B. C., Restrepo, A., & Piñeros, V. J. (2003). Effects of different levels of harvesting on female size and reproduction in trachemys scripta callirostris. Abstracts ASIH Meeting 2003.
Added by: Admin (14 Aug 2008 20:36:26 UTC) Last edited by: Sarina Wunderlich (16 Oct 2008 11:38:18 UTC) |
| Resource type: Journal Article BibTeX citation key: Paez2003a View all bibliographic details  |
Categories: General Keywords: Emydidae, Fortpflanzung = reproduction, Habitat = habitat, Schildkröten = turtles + tortoises, Südamerika = South America, Trachemys, Trachemys callirostris, Trachemys scripta Creators: Bock, Daza, Páez, Piñeros, Restrepo Collection: Abstracts ASIH Meeting 2003 |
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| Abstract |
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We determined the effects of differing levels of human exploitation on nesting female size in the slider turtle, Trachemys scripta callirostris, from five locations in the Mompos Depression in northern Colombia. We also studied basic reproductive ecology during two nesting seasons in a semi-protected area in the same region. We characterized and quantified habitat available for nesting and examined the number of nests ovoposited in locations with differing characteristics, their hatching success rates, the natural causes of egg mortality, incubation temperatures, and sex ratios of the hatchlings produced. Clutches obtained from harvested females also were incubated under varying semi-natural and artificial incubation conditions. Preliminary results indicated that the majority of nests were oviposited within the first 20 meters from shoreline in sites with sandy or clayish textured substrates with moderate humidities that often were covered by herbaceous vegetation. Invertebrates were the greatest source of mortality to natural nests, although hatching success in the focal study population was high compared to other reports for this species. Only in the site with the highest hunting pressure was a negative correlation found between daily harvest rates and the time elapsed since the beginning of the nesting period, suggesting that the excessive extraction of females there significantly affected the pool of available adult females. Females from this highly exploited site also were significantly smaller than those from less exploited sites. Females, neonates, and nests throughout the entire region exhibited sizes lower than those reported for other tropical populations of the genus. The continued hunting pressure in northern Colombia appears to be a factor that has altered the structure and dynamics of Trachemys scripta callirostris populations to varying degrees.
Added by: Admin Last edited by: Sarina Wunderlich |