Chapter 21

1. Chapter 21 Conservation Biology and Wildlife Management http://pop.bio.txstate.edu/images/venn2.gif

2. Conservation Biology • Multi-disciplinary field emerging in the US in the 1980s • First started in Australia, but traces roots to ancient times • “Tragedy of the commons” • 1970s increased interest in “non-resource” species • Protection of natural world for aesthetic and ethical reasons • Primary interest in maintenance of diversity at three levels • Genes • Species • Ecosystem

3. Conservation Biology • Overlaps significantly with natural resource fields • Fisheries biology • Forestry • Wildlife Management • Two main differences – Wildlife management • Utilitarian, economic objectives • Financial resources go to enhancing commercial and recreational values for humans – “Our natural resources” • The nature of the resources • Primarily focused on small number of “valuable” species

4. Con Bio vs Wildlife Mgmt • The Wildlife Society (1937)– conserve wildlife and their habitats • Manipulation of animal populations – primarily vertebrates • Selected species of birds and mammals • Society for Conservation Biology (1986) – maintaining integrity of ecosystems • Crisis oriented • More theoretical • More global • Broader approaches • Maintenance of biological diversity • Full range of plant and animal taxa Differences really mostly superficial (See Table 21-1 on p.467 of text)

5. Conservation Biology Crisis-oriented discipline “Discipline with a deadline” – E.O. Wilson The preservation of ecosystems is not only important, but urgent Need for immediate application of scientific knowledge Conservation biology is to ecology as Surgery is to physiology War is to political science Mixture of science and art, uses intuition as well as information

6. “What is Conservation Biology?”-Michael Soulé (1986) Bioscience Vol.35 no. 11

7. Biodiversity • “The goal of conservation biology is to protect Earth’s biodiversity.” Alan Christian • Preservation of threatened and endangered species and their genetic diversity • Conservation of whole faunas and maintenance of ecosystems • Halting unprecedented loss of genes, species and ecosystems • Biodiversity • is the variation of life forms within a given ecosystem, biome or for the entire Earth • is often used as a measure of the health of biological systems.

8. Biodiversity is important for Functional (mechanistic) reasons Many species in communities are products of coevolutionary processes Species are interdependent Many species are highly specialized Ecological processes have thresholds beyond which they become discontinuous, chaotic or suspended Genetic and demographic processes have thresholds below which nonadaptive random forces prevail Nature reserves are inherently disequilibrial for large, rare organisms

9. Biodiversity is important for Normative (ethical) reasons Diversity of organisms is good Ecological complexity is good Evolution is good Biotic diversity has intrinsic value

10. Levels of Conservation Biology • Preservation of genetic diversity • Population genetics • Inbreeding/outbreeding depression – cheetahs, ibex • Genetic bottleneck • Only a few individuals provide total genes – wolves of Isle Royale • Founder effect • Small gene pool particular to descendents of a few “founders” – lions in the Ngorongoro Crater • Preservation of species diversity • Food webs • Community relationships • Preservation of ecosystem diversity • Ecological relationships

11. Concepts of Conservation Biology • Island biogeography/Fragmentation • Factors affecting species richness – number of species that may exist on sites of various size • Species-Area relationship - Large sites contain more species than smaller ones • More likely to be colonized by new species • Less likely to experience extinctions • Distance between areas affects stability of metapopulations (distance from “mainland”) • Minimum area required for nature reserves

12. Influencing factors Degree of isolation (distance to nearest neighbour, and mainland) Length of isolation (time) Size of island (larger area usually facilitates greater diversity) Climate (tropical versus arctic, humid versus arid, etc.) Location relative to ocean currents (influences nutrient, fish, bird, and seed flow patterns) Initial plant and animal composition if previously attached to a larger land mass (e.g., marsupials, primates, etc.) The species composition of earliest arrivals (if always isolated) Serendipity (the impacts of chance arrivals) Human activity

13. Spotted Owl • Well-distributed species are less prone to extinction • Large habitat blocks with many individuals preferable • Patches near each other are better than far apart • Contiguous blocks better than fragmented • Sites between patches enhance dispersal when closely resembling suitable habitat

14. Assumptions of Island Biogeography All species treated equally Environment on island remains constant No allowance made for increases in number of species by evolution

15. Concepts of Conservation Biology • Corridors • Connections between separate areas of similar habitats • Preventing inbreeding depression by maintaining gene flow • Enhancing species richness • May offset negative consequences of fragmented habitat • Less than full agreement about benefits • Table 21-3, p. 484 • Population sinks • Translocation as alternative http://www.adb.org/Projects/GMS-biodiversity/img/biodiversity.gif

16. Concepts of Conservation Biology • Hot Spots • Areas where biodiversity still remains relatively unchanged • 25 sites = less than 1.5% land surface = critical habitat for 44% vascular plants and 35% terrestrial animals • Considered conservation priorities

17. Concepts of Conservation Biology • Minimum Viable Populations • NFMA 1976 charges USFS to maintain “viable populations” for all vertebrates in national forests • This “magic number” a moving target • Requires maintenance under average and extreme/random conditions • Large mammals • >50 to cope with short-term effects of inbreeding • >500 for long-term maintenance • May be just a few individuals • Saving 2 female northern right whales allows increase of population to replacement level

18. Concepts of Conservation Biology • MVP • The smallest isolated population having a 99% chance of remaining extant for 1000 years despite the foreseeable effects of demographic, environmental, and genetic stochasticity and natural catastrophies • Must include explicit set of performance criteria • Area required increases with increases of MVP and length of time

19. Concepts of Conservation Biology • Deterministic (systematic) factors • Outcome is predictable if conditions are unchanged • Hunting, habitat destruction • Stochastic (random) factors • Decrease chances of survival • Demographic • Skewed sex ratio • Genetic • Bottleneck • Environmental • Parasitism • Natural catastrophies • Floods

20. Global warming • Change too rapid for ecosystems to adapt • Migration of vegetation • Decoupling of food supply and breeding times • Habitat changes • Disease patterns

21. Human Population Growth • Rapid population growth conflicts with natural environment • “will continue to be degraded at the hands of profiteers, short-term thinkers, the uninformed and those blameless unfortunates who are simply struggling to stay alive in an overcrowded world.” – Meffe et al. • A conservation biologist would: • Seek interactions with demographers, sociologists and epidemiologists • Strongly advocate controlling human populations

22. Conservation Medicine “Emerging, interdisciplinary field that studies the relationship between human and animal health, and environmental conditions. Also known as ecological medicine, environmental medicine, or medical geology.” Wildlife Trust Tufts University

23. A case in point:

24. 70% of known FW mussels are endangered, threatened or at risk • 90% of North American FW mussels are in the Southeast USA • FW mussels rely on a fish host to complete their life cycle

25. FW mussel habitat has been fragmented by dams • Bypasses for fish = corridors • Certain species of FW mussels have been shown to be sensitive to increases in temperature • No migration option for FWM! • Increased demands on water supply has pitted human consumption vs need for aquatic species • Drought pressures have exacerbated this • Minimum viable population? • Defined here as below which fertilization is not ensured