Extinction

1. Extinction

2. What makes species vulnerable to extinction? The dodo

4. Passenger pigeon

5. Passenger pigeon

6. Allee Effect • Some species have a minimum requirement for population size in order to successfully breed

7. Characteristics that predispose species to becoming extinct 1. habitat overlap - the species occupy habitat that is desirable to humans and lose out in competition with humans for the habitat - tallgrass prairie species 2. human attention - species suffer because singled out by humans - either desired as food or fur and hunted heavily (passenger pigeon, dodo, northern elephant seal); or disliked by humans and killed as varmints (wolves, African wild dogs) 3. large home range requirements - animals needing large areas can’t find large enough areas in human dominated landscape - California condor 4. limited adaptability and resilience - salmon return to natal stream to reproduce; won’t go elsewhere

8. Konza Prairie – Kansas

9. African wild dog

10. California Condor

11. Coho salmon

12. Salmon Life Cycle

13. Coho Salmon support 137 species

16. Worldwide Endangered Species

17. Endangered tree species - worldwide

18. Rare and Endangered Species in Japan

19. Endangered species in Canada and the US – as of 1990’s

20. Threatened and Endangered Species

21. Threatened And Endangered Species in Illinois

22. Four-toed salamander – found at Green Oaks

23. Minimum Viable Population • The smallest population for a species which can be expected to survive for a long time • Many factors effect MVP – the study of those factors is often called Population Viability Analysis – or Population Vulnerability Analysis – or PVA

24. Factors that make populations vulnerable to extinction • Environmental fluctuations • Catastrophes • Demographic uncertainties • Genetic problems • Habitat fragmentation

25. Environmental Fluctuations

26. Kirtland’s Warbler

29. Cheetah

31. Habitat Fragmentation • Fragmentation is the transformation of large expanse of habitat into a number of smaller patches of smaller total area isolated from each other by a matrix of habitat unlike the original

32. Domesday Book – 1085-86

33. Selection from the Domesday Book

35. Factors that make populations vulnerable to extinction • Environmental fluctuations • Catastrophes • Demographic uncertainties • Genetic problems • Habitat fragmentation

36. Heath Hen – Extinction Vortex

37. Minimum Viable Population Size • Another definition - often defined as 95% probability of 100 year survival, but can also plan for longer survival (500 or 1000 years) • MVP is usually determined by modeling

38. Forces which may cause extinction 1) deterministic - something essential is removed (habitat loss) or something lethal is added (pollutant, disease, introduced species) - presumably we can act to minimize these risks

39. Forces which may cause extinction 2) stochastic (random) - environmental, catastrophic, demographic and genetic - this is what we need to worry about and what is hardest to prevent • environmental randomness effects resources and conditions and we can't do much about it • catastrophic randomness - floods, fires, hurricanes, volcanoes - can't really prevent but can spread individuals around to minimize the impact • demographic - just natural random variation in birth and death rates can lead to extinction • genetic - lack of genetic variability can lead to problems of inbreeding and poor response to diseases and environmental change

40. Grizzly Bear and 50/500 Rule

42. MVP – 50/500 Rule?

43. English Skylark