Multiyear multiple paternity and mate fidelity in the American alligator, Alligator mississippiensis


  • S.L.L. studies local scale processes such as breeding strategies, survivorship, and dispersal and their combined effects on the maintenance and distribution of genetic diversity within and among populations. In addition, she examines the effect of environmental contaminant exposure on the interplay of behavior, demography, and population genetics. T.D.T. studies the conservation and management of reptile and amphibian populations with an emphasis on translocations and reintroductions. She also is interested in using genetics and long-term mark-recapture data as tools to better understand the ecology and life history of reptiles and amphibians. R.M.E. and P.L.T. study alligator ecology, physiology, nesting behavior, harvest management, egg ranching, and captive husbandry. In addition they both are very interested in waterfowl management. T.C.G. develops and uses DNA technologies to make discoveries and solve problems in ecology, evolution, and environmental health. Massively parallel sequencing technologies and non-traditional biomedical model organisms are current areas of emphasis. L.D. is interested in the application of genetic analyses to conservation practice. In particular she examines the conservation genetics of captive and wild red pandas and the molecular phylogeny of the orchid genus Spiranthes with implications for endangered taxa.

Stacey L. Lance, Fax: 803-725-3309; E-mail:


We examined multiple paternity during eight breeding events within a 10-year period (1995–2005) for a total of 114 wild American alligator nests in Rockefeller Wildlife Refuge in south-west Louisiana. Our goals included examining (i) within population variation in multiple paternity among years, (ii) variation in multiple paternity in individual females and (iii) the potential for mate fidelity. To accomplish this, in the current study, eggs were sampled from 92 nests over 6 years and analysed along with 22 nests from a previous 2-year study. Genotypes at five microsatellite loci were generated for 1802 alligator hatchlings. Multiple paternity was found in 51% of clutches and paternal contributions to these clutches were highly skewed. Rates of multiple paternity varied widely among years and were consistently higher in the current study than previously reported for the same population. Larger females have larger clutches, but are not more likely to have multiply sired nests. However, small females are unlikely to have clutches with more than two sires. For 10 females, nests from multiple years were examined. Seven (70%) of these females exhibited long-term mate fidelity, with one female mating with the same male in 1997, 2002 and 2005. Five females exhibiting partial mate fidelity (71%) had at least one multiple paternity nest and thus mated with the same male, but not exclusively. These patterns of mate fidelity suggest a potential role for mate choice in alligators.