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SelectedWorks

Selected Works

2009

Recruitment

Articles 1 - 2 of 2

Full-Text Articles in Life Sciences

Demographics Of A Geographically-Isolated Population Of Threatened Salamander (Caudata: Ambystomatidae) In Central Illinois, Stephen J. Mullin, Sarabeth Klueh Jan 2009

Demographics Of A Geographically-Isolated Population Of Threatened Salamander (Caudata: Ambystomatidae) In Central Illinois, Stephen J. Mullin, Sarabeth Klueh

Stephen J. Mullin

Amphibian populations that use small isolated wetlands are often small in size, susceptible to stochastic extinction processes, and have little to no contact with other populations. One can ascertain the persistence of such populations only by obtaining data that allow the prediction of future changes in population’s size, and propensity to achieve a sustainable number of individuals. The number of metamorphosing larvae leaving a pond predicts the viability of a salamander population, and thus, the number recruited into the terrestrial adult population. The Jefferson Salamander, Ambystoma jeffersonianum, is a listed threatened species in Illinois, occurring at fewer than 15 ponds …


Consequences Of Recruitmentdecisions And Heterogeneity On Age-Specific Breeding Success In A Long-Lived Seabird, L. M. Aubry, David N. Koons, J. Y. Monnat, E. Cam Jan 2009

Consequences Of Recruitmentdecisions And Heterogeneity On Age-Specific Breeding Success In A Long-Lived Seabird, L. M. Aubry, David N. Koons, J. Y. Monnat, E. Cam

David N. Koons

An individual’s age at first reproduction and investment in successive reproductive attempts are involved in mechanisms that can impede somatic repair, resulting in a decline in reproductive abilities with age (reproductive senescence). We used long-term data from the Black-legged Kittiwake, a long-lived seabird, to address the relationship between recruitment age, age-specific breeding success (BS), and reproductive senescence, while accounting for breeding experience and temporal variation in BS. We first detected late-life improvement in BS across all recruitment groups, which we recognized as ‘‘within-generation selection’’ or the selective disappearance of ‘‘frail’’ phenotypes. When such heterogeneity was accurately accounted for, we showed …