We studied the reproductive ecology of female Sonora mud turtles (Kinosternon sonoriense) at Montezuma Well, a chemically-challenging natural wetland in central Arizona, USA. Females matured between 115.5 and 125 mm carapace length (CL) and 36-54% produced eggs each year. Eggs were detected in X-radiographs from 23 April-28 September (2007-2008) and the highest proportion (56%) of adult females with eggs occurred in June and July. Clutch frequency was rarely more than once per year. Clutch size was weakly correlated with body size, ranged from 1-8 (mean = 4.96) and did not differ significantly between years. X-ray egg width ranged from 17.8-21.7 mm (mean 19.4 mm) and varied more among clutches than within. Mean X-ray egg width of a clutch did not vary significantly with CL of females, although X-ray pelvic aperture width increased with CL. We observed no evidence of a morphological constraint on egg width. In addition, greater variation in clutch size, relative to egg width, suggests that egg size is optimized in this hydrologically stable but chemically-challenging habitat. We suggest that the diversity of architectures exhibited by the turtle pelvis, and their associated lack of correspondence to taxonomic or behavioral groupings, explains some of the variation observed in egg size of turtles.
The extreme environment, trophic structure, and ecosystem dynamics of a large, fishless desert spring – Montezuma Well, Arizona. In:
Aridland Springs in North America – Ecology and Conservation
University of Arizona PressTucson.
Analyses of the Biota in the Aquatic Habitats of Montezuma Castle National Monument. Montezuma Castle National Monument Integrated Inventory and Monitoring Studies
U.S. Department of Interior, National Park Service, Colorado Plateau Research StationFlagstaff, AZ.
Overcoming environmental and morphological constraints: Egg size and pelvic kinesis in the smallest tortoises, Homopus signatus.
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Hydrogeology and water chemistry of Montezuma Well in Montezuma Castle National Monument and surrounding area, Arizona. In:
U.S. Geological Survey Water Resources Investigations Report 97-4156
Distribution of native turtles in the arid southwestern United States with comments on Kinosternon sonoriense: A species presumed to be lost from California’s herpetofauna. In:
The 2008 Desert Symposium and Field Guide and Proceedings
California State University, Desert Studies Consortium and LSA Associates, Inc.
Macip-RíosR.Arias CisnerosM.L.Aguilar-MiguelX.S.Casas-AndreuG. (2009):
Population ecology and reproduction of the Méxican mud turtle (Kinosternon integrum) in Tonatico, Estado de México.
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Clutch and egg allometry of the turtle Mauremys leprosa (Chelonia: Geoemydidae) from a polluted peri-urban river in west-central Morocco.
Van Loben SelsR.C.CongdonJ.D.AustinJ.T. (1997):
Life history and ecology of the Sonoran mud turtle (Kinosternon sonoriense) in southeastern Arizona: A preliminary report.
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Buoyancy, locomotion, morphology of the pelvic girdle and hindlimb, and systematics of cryptodiran turtles.
Miscellaneous Publications Museum of Zoology University of Michigan142: