1. Populations

2. Population - a group of organisms of the same species which have the potential to interbreed – or a population is a group of organisms occupying a particular place at a particular time Populations have a number of properties which are not possessed by individual organisms - this is because a population is the sum of many organisms interacting

4. Prairie Dog Distributions

5. Properties dealing with changes in population size Natality - may think of this as births, but includes more than just birth - hatching, germination, fission Natality includes idea of fecundity - number of offspring produced per unit time - we are most concerned with realized fecundity - actual number of survivors Mortality - death rate - its converse is survivorship - mortality looks at how many die per unit time, survivorship at how many don't die per unit time Longevity examines life-span of individuals - again we are most interested in realized longevity, not potential longevity Immigration - individuals moving into a population Emigration - individuals leaving a population

6. What is an individual? unitary organism - individuals are highly determinate in form and while growing pass through predictable (innately determined) sequences of life history stages modular organisms - zygote develops into unit, or module, which produces more modules thus producing an organism with a variable number of modules, whose development is unpredictable and strongly influenced by environmental factors

7. A classic unitary organism

8. A classic modular organism Bryozoan colony

9. More classic modular organisms

10. Genets and Ramets ramet - a module with the potential for a separate existence genet - the "genetic individual"; the collection of all modules derived from a single zygote

11. A single Aspen clone

12. Posidonia oceanica – Neptune grass

13. Sampling to collect population data Census - most basic sampling - count and determine age of all individuals in population, count again later Several ways to subsample: 1. Determine total area in which population occurs, count all individuals in small plots, multiply average number in plots to get total, repeat at later dates - works best for sessile organisms 2. Mark-recapture methods 3. Catch per unit effort 4. Miscellaneous methods – traps, counts of fecal pellets, counts of vocalizations, feeding damage on plants, roadside sightings, fur or pelt records, roadkill

14. Quadrat Sampling

15. Mark recapture of Cicadas

16. Catch per unit effort – Pacific Threadfin

17. Beetles feeding on Viburnum

18. Beetle damage on Viburnum

19. Bird migration data – typical altitude – from radar

20. Bird migration radar map

21. Skylark

23. Metapopulations A metapopulation is a series of small, separate populations united together by dispersal

24. Metapopulation Dynamics

26. Metapopulations of Bay Checkerspot Butterfly

27. Aphids and Epilobium

28. Habitat fragmentation in Amazonia

29. Demography

30. Demography is the study of processes that influence population size - it is the way we study changes brought about by births, deaths and dispersal For Northwest Montana, Greater Yellowstone, Central Idaho

31. The Fundamental Equation of Ecology – Harper 1977 Δ N = B – D + I – E Change in Number = Births – Deaths + Immigration - Emigration John L. Harper – 1925-2009

32. Rearrange Fundamental Equation Δ N = B – D + I – E N future = N now + B – D + I – E

33. Common Field Grasshopper