Document: SHA-3-51-4

Influence of life history strategies on bird population responses to stress.

SABLE, S.E.*, K.A.ROSE and J.E.AUGUSTINE

Louisiana State University, Baton Rouge, LA, U.S.A. ¹

Abstract:
We constructed stage-based matrix models of 25 bird species and related their predicted responses to stress to their life history traits. All species were modeled using up to eight life stages and a minimum of a weekly time step. Stage-specific survival, reproduction, and growth rates reported in the literature were used to tailor the model to the biology of each species. Density-dependence and interannual stochasticity were imposed on various combinations of life stages for each species. Life history traits of the 25 species were also recorded and clustering statistical methods were applied to identify major life history strategies. Multiple 200-year simulations were performed under baseline (stable conditions) and under stressed conditions, simulated by mortality increases for each life stage individually and all life stages simultaneously. Predicted long-term average population abundance was compared between baseline and stressed simulations. The magnitudes of predicted responses were correlated with the life stage stressed and life history traits such as longevity, degree of parental care, and the life stage in which density-dependence occurred. We propose a variation of the classical r-K continuum of life history strategies for birds that better correlates their predicted responses to stress to their life history traits.

Keywords: matrix models, life history, stress

This abstract is being presented at: 9:00 AM in session:
Oral Session #3: Avian Ecology.