Evol Ecol Res 4: 563-576 (2002) Full PDF if your library subscribes.
Fitness consequences of delayed maturity in female wood ducks
Madan K. Oli,1* Gary R. Hepp2 and Robert A. Kennamer3
1Department of Wildlife Ecology and Conservation, University of Florida, 303 Newins-Ziegler Hall, Gainesville, FL 32611, 2School of Forestry and Wildlife Sciences, Auburn University, 108 M. White Smith Hall, Auburn, AL 36849-5418 and 3Savannah River Ecology Laboratory, The University of Georgia, PO Drawer E, Aiken, SC 29802, USA
Author to whom all correspondence should be addressed.
Age at maturity has been suggested to be an important life-history trait with substantial potential for influencing the evolution of life histories. Using known reproductive histories of 90 female wood ducks (Aix sponsa) from a long-term study (1982–96), we investigated the fitness consequences of changes in age at maturity. Female wood ducks that attained sexual maturity as yearlings had a significantly shorter lifespan than those that delayed reproduction until 2 years of age or later. However, females that delayed reproduction neither produced a larger number of ducklings during their first reproductive event, nor did they have a greater number of successful lifetime breeding attempts than those maturing as yearlings. Females that attained sexual maturity as yearlings had the greatest individual fitness; the results indicated a directional selection for early maturity. These results are consistent with life-history theory predictions and suggest that reduced lifespan in female wood ducks is the primary cost associated with early maturity; however, costs of early maturity are outweighed by the associated benefits in fitness currency. Regression of individual fitness on age at maturity indicated strong directional selection for early maturity. These results suggest that attaining sexual maturity as yearlings may be an evolutionarily stable strategy in our study population, and that females delaying reproduction do so because they are genetically or environmentally constrained, not because of the potential fitness benefits of delayed maturity.
Keywords: age at maturity, Aix sponsa, cost of reproduction, demography, fitness, individual fitness, life-history evolution, life-history trade-offs, lifetime reproductive success, wood duck.
DOWNLOAD A FREE, FULL PDF COPY
IF you are connected using the IP of a subscribing institution (library, laboratory, etc.)
or through its VPN.
© 2002 Madan K. Oli. All EER articles are copyrighted by their authors. All authors endorse, permit and license Evolutionary Ecology Ltd. to grant its subscribing institutions/libraries the copying privileges specified below without additional consideration or payment to them or to Evolutionary Ecology, Ltd. These endorsements, in writing, are on file in the office of Evolutionary Ecology, Ltd. Consult authors for permission to use any portion of their work in derivative works, compilations or to distribute their work in any commercial manner.
Subscribing institutions/libraries may grant individuals the privilege of making a single copy of an EER article for non-commercial educational or non-commercial research purposes. Subscribing institutions/libraries may also use articles for non-commercial educational purposes by making any number of copies for course packs or course reserve collections. Subscribing institutions/libraries may also loan single copies of articles to non-commercial libraries for educational purposes.
All copies of abstracts and articles must preserve their copyright notice without modification.