1. FW 491 – Online Ecological Module By: Jessica Caton

2. Introduction to Population Ecology What is a population? – A group of individuals of a single species inhabiting a specific area (Molles 2010, p. 202) Areas of study involved – Population genetics – Population dynamics

3. Population Dynamics An area of population ecology concerned with the factors influencing the expansion, decline, or maintenance of populations (Molles 2010, p. 222) Increases = Birth and Immigration Decreases = Death and Emigration

4. Population Dynamics (con’t) Important for ecology to understand/prevent decline and extinction of endangered species

5. Antarctic Species of Interest: Adélie Penguin (Pygoscelis adeliae) Physical appearance: – Medium-sized (2 feet tall), black and white – Angular head and tiny bill – White eyering – Longest feather on body is the tail Smallest penguin in Antarctica One of the pack ice Antarctic penguins Most numerous bird in Antarctica

6. Adélie Penguins and Climate Change One of the best studied birds Changing population of species: numbers dropped a third Sea-ice decline, Adélie penguin populations decline Evolution of environmental instability?

7. Life Tables A table that uses age specific information to estimate important population dynamic traits on a population Types of life tables: – a table based on individuals born (or beginning life in some other way) at same time (Molles 2010, p. 230) – Static life table: a life table constructed by recording the age at death of a large number of individuals; a snapshot of survival within a population during a short interval of time (Molles 2010, p. 231)

8. Life Table Summary Time Cohort (horizontal) Composite Time-specific (static, vertical)

9. Data Collection for Life Table

10. Variables in Life Tables n x l x m x l x m x R 0 R 0 = ∑l x m x

11. Survival and Mortality in a Population of Adélie Penguins (Ainley & DeMaster 1980)

12. Survivorship Curve A graphical summary of patterns of survival in a population (Molles 2010, p. 231) Three types: – Type 1 = High mortality in older individuals – Type 2 =Constant mortality rate – Type 3 =High mortality in juveniles