The demography and dynamics of heterogeneous populations
Predicting how the abundance of populations of plants and animals will change through time depends on recognizing differences among individuals, e.g., young vs. old, mature vs. immature, and on how those differences affect individual survival, growth, development, and reproduction, collectively known as the vital rates. Mathematical models based on these vital rates play an important role in both basic and applied population ecology. For example, they can measure the impact of environmental factors on population dynamics, evaluate strategies for the management of natural resources, and project the consequences of global change on species abundance. However, in addition to obvious differences among individuals, all populations contain some level of heterogeneity among individuals that cannot be measured. This heterogeneity may result from physiological processes driven by food availability, genetic variation, individual history, or environmental effects. This project will develop new mathematical models that include such types of heterogeneity. The population demographic models will be analyzed to quantify the effects of heterogeneity on population growth and sensitivity patterns, and applied to long-term data on Antarctic seabird populations. Educational outreach is a critical aspect of mathematical research in ecology. With the goal of making the results of the research more widely accessible to other researchers, an educational workshop will be organized at the national Annual Meeting of the Ecological Society of America. The models that result from this work will also have practical application in the management of wildlife populations, and in conservation biology.