Literaturdatenbank
Literaturdatenbank |
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Christopher, T. E., Henen, B. T., Smith, E. M., Allen, M. E., Pough, H. F., & Oftedal, O. T. , Reproductive output of large-for-age desert tortoises (gopherus agassizii). Paper presented at 23rd Annual Meeting and Symposium of the Desert Tortoise Council.
Added by: Sarina Wunderlich (24 May 2009 21:32:16 UTC) |
| Resource type: Proceedings Article BibTeX citation key: Christopher1998 View all bibliographic details  |
Categories: General Keywords: Ernährung = nutrition, Fortpflanzung = reproduction, Gopherus, Gopherus agassizii, Habitat = habitat, Nordamerika = North America, Schildkröten = turtles + tortoises, Testudinidae Creators: Allen, Christopher, Henen, Oftedal, Pough, Smith Collection: 23rd Annual Meeting and Symposium of the Desert Tortoise Council. |
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| Abstract |
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Testudinidae Gopherus agassizii Small juvenile desert tortoises maintained on a high plane of nutrition since 1991 had reached an adult body size (> 180 mm carapace length) by 1995. Are such large-for-age (LFA) tortoises reproductively competent? In 24 outdoor pens, ten LFA females and eight LFA males (sex assessed from plasma testosterone and estradiol levels) were paired with ten adult males and eight adult females, respectively, and six adult females were paired with six adult males to serve as a control group. Following initial behavioral observations, follicular development was monitored with ultrasonagraphy in Fall 1995 and Spring 1996, and clutch size was measured with radiography in Spring 1996. In Spring 1996, all 14 adult females laid eggs. However, only two LFA females produced eggs (one clutch per female, two eggs per clutch). Every adult female had some eggs hatch. Only one of the two clutches from LFA females was found and the eggs showed no signs of development. LFA females remained paired with adult males throughout 1996 and Spring 1997. In 1997, five LFA females laid a total of six clutches. Eggs from two clutches, both from one LFA female, hatched. LFA females that had laid eggs in 1996 also laid eggs in 1997, but these were infertile. LFA males were reproductively competent but LFA females were not.
Added by: Sarina Wunderlich |