PARENT SESSION
Contributed Oral Session 145: Evolutionary Ecology: Population Dynamics
Thursday, August 11, 1:30 PM - 5:00 PM, Meeting Room 524 B, Level 5, Palais des congrès de Montréal
Revealing the internal structure of species distribution: A metapopulation approach to Piñon jays (Gymnorhinus cyanocephalus) in the USA.
Samaniego, Horacio *,1, Milne, Bruce1, 1 Dep. Biology University of New Mexico, Albuquerque, NM, USA
ABSTRACT- The study of limits to species distribution is an active research topic in ecology. Mathematical modeling and field observations have shown that population dynamics may be driven by environmental and demographic processes. However, there is no clear notion as to how to quantify and compare the forces that drive population dynamics within a species distribution. Theoretical research should address practical issues that may give conservation practitioners tools to address the state of wildlife populations. The objective of the present work is to propose a new way to represent the relative importance of population parameters in the context of species distribution range. We propose that changes in population sizes (N) over space (x,y) can be approximated by the relative contribution of the different parameters (c,e, and k) that may describe population dynamics, at a particular site. Using this approximation we can assess which term governs the population dynamics at each location within species range provided that e, c, and k are measured accurately throughout the landscape. We applied a metapopulation approach to the Piñon Jay (Gymnorhinus cyanocephalus) distribution in the US. Using 33 years of data from the Breeding Bird Survey, we evaluate our model and determine that habitat suitability is most important to population persistence in sites of high abundances. We also determine that extinction factors are important in particular places of the range and that colonization seems to have an overall relevance everywhere else. This approach provides a simple yet powerful method to investigate the internal structure of species ranges that, combined with species natural history information, may prove to be a valuable tool to understand and manage wild populations.
Key words: Species Boundaries, Distribution Range, Population Parameters, Metapopulation