Conservation Biology of Single Species - PowerPoint PPT Presentation

JasminFlorian
conservation biology of single species l.
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Conservation Biology of Single Species

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  1. Conservation Biology of Single Species Choice of Species: “so many endangered, so little money”

  2. Statement reflects the number of endangered species listed (1,889 U.S. and Foreign) and the amount of money budgeted for administering the Endangered Species Act ($37 million in 1991; around $146 million 2009)http://www.fws.gov/endangered/wildlife.html

  3. 4 / 15 / 2009 – Endangered Species Act Species Recovery Endangered Threatened Total Plans Mammals 325 33 358 55 Birds 254 21 275 85 Reptiles 79 40 119 38 Amphibians 22 12 34 17 Fishes 85 66 151 102 Snails 25 11 36 30 Clams 64 8 72 70 Crustac 19 3 22 18 Insects 51 10 61 40 Arachnids 12 0 12 12 Plants 601 148 749 664 TOTAL 1,537 352 1,889 1,131 (589)

  4. Endangered Species by Statehttp://www.endangeredspecie.com/map.htm

  5. For many reasons a habitat, community or ecosystem level approach would be the more astute thing to do, however, at present there are too many economic and legal blockades to such an approach- at present only 1.6-2.5% of the land is in preserve or protected

  6. Therefore, we take a single-species approach, and because we take a single-species approach we need to choose species carefully, given that there are so many endangered and so little money

  7. Choosing Species - Criteria should include: • Likelihood of extinction • Likelihood that we can help the species • Taxonomic distinctiveness • Ecological “key” species • “Flagship” species (e.g., spotted owl)

  8. Listing Process • Endangered Species Act • Biodiversity Network Ranking - Natural Heritage • IUCN: Previously based on PVA analysis • CITES - Convention on International Trade in Endangered Species • Appendix I 953 species - trade prohibited • Appendix II 4359 animals, 28674 plants trade regulated • Appendix III 171 animals, species trade controlled – not necessarily threatened with extinction globally, e.g., alligator snapping turtle in U.S.

  9. Endangered Species Act Listing a species, subspecies or population - the process begins by Secretary initiation (Secretary of Interior through the Fish and Wildlife Service for most species and for marine species, the Secretary of Commerce through the National Marine Fisheries Service) or through a petition from some group (a State or Federal Agency) or a private citizen

  10. The law permits them to list a plant or animal for any of the following five reasons: • Present or threatened destruction of habitat • Over-utilization for commercial, recreational, scientific, or educational purposes • Losses due to disease or predation • The inadequacy of existing laws and regulations to protect the organism in question • Other natural and manmade factors affecting its continued existence

  11. Species, subspecies and populations are listed as either endangered or threatened (all referred to as “species”) - An Endangered Species is any species which is in danger of extinction throughout all or a significant portion of its range - A Threatened Species is any species which is likely to become an endangered species within the foreseeable future throughout all or a significant portion of its range

  12. Following the request or initiation to list a species, is a collection of information and public input

  13. Based on this information, the U.S. Fish and Wildlife Service ranks species for listing (on a scale of 1-12) according to magnitude (high or low probability of extinction), immediacy of threat (imminent or nonimminent), and taxonomic distinctiveness (monotypic genus, species, subspecies)

  14. The Secretary may not take into account the economic effects that listing may have on the area where the species occurs. Congress felt that listing was fundamentally a scientific question: is the continuation of the species threatened or endangered

  15. If the FWS or NMFS determines that listing a particular plant or animal species is warranted, it publishes a notice of its intent to do so in the Federal Register and in local newspapers. The proposal notice states the reasons for listing and solicits public commenthttp://www.fws.gov/policy/frsystem/1999rules.cfm?date=09&doc_type=proposed

  16. A final listing determination must be made within a year of publishing the proposal. Notice of a final decision is published in the Federal Register and once again the rationale for the decision is given

  17. Listing Procedure Outline

  18. Of course there are controversies surrounding the way in which taxa are listed - Some have argued that the act protects taxa that are not truly endangered - Others have argued that by the time many species are officially listed, their numbers are so low that prospects for recovery are poor - Still others have commented that the distinction between threatened and endangered taxa appear to have no uniform biological meaning

  19. Controversies in Listing Taxa - Critics also contend that the growing roster of endangered taxa reflects the addition of numerous subspecies and populations, rather than full species, to the list. There has been a cry to revise the law so that only full species are eligible for protection

  20. Are these accusations correct? Is there anything valid in these statements? To address some of these criticisms I want to share the results of the findings of Wilcove et al. 1993. What exactly is an endangered species? An analysis of the U.S. Endangered Species List: 1985-1991. Conservation Biology

  21. Only 20% of species listed or proposed for listing were subspecies or populations Taxonomic group n Species Subsp Pop % Subsp % Pop Mammals 23 7 16 0 70 0 Birds 15 3 8 4 53 27 Reptiles 10 6 2 2 20 20 Amphibians 3 3 0 0 0 0 Fishes 43 30 11 2 26 5 Arthropods 23 18 5 N.A. 22 N.A. Mollusks 43 41 2 N.A. 5 N.A. Plants 332 286 46 N.A. 14 N.A. Total 492 394 90 8 18 2

  22. Important to note that the ability to list individual populations is an example of the Endangered Species Act’s flexibility Removal of subspecies and populations from the ESA would eliminate special protection for some of the most charismatic endangered animals, including grizzly bear, peregrine falcon, Florida panther, and gray wolf

  23. Early intervention is critical to the success of endangered species recovery Yet their analyses indicate that most species, subspecies and populations are not receiving protection until their total population size and number of populations are critically low

  24. Median # Animals = 999: 1075 vertebrates, 999 invertebrates # Listed Taxa 0 >100,000 101-1000 100,000 11-100 10,000 Total # Individuals 1-10

  25. Median # Plants = 119.5 # Listed Taxa 0 1-10 10,000 100,000 11-100 >100,000 101-1000 Total # Individuals

  26. Median # Populations of Animals = 2.5; 2 vertebrates, 3 invertebrates # Listed Taxa 1-5 0 16-20 6-10 21-25 11-15 >25 # Populations

  27. Median # Populations of Plants = 4.0 # Listed Taxa 0 6-10 1-5 11-15 21-25 16-20 >25 # Populations

  28. Population viability analysis also supports the contention that protection is coming too late for most species For example the IUCN Captive Breeding Specialist Group recommends that captive populations be established for vertebrate species with wild populations below 1000 individuals

  29. Vertebrates The median total population size of a vertebrate at the time of listing - 1075 individuals - is close to this number However, effective population size is often less than 1/2 or as little as 1/4 the total population size - resulting in greater loss of genetic diversity

  30. Invertebrates The small body sizes and shorter lifespans make invertebrates especially vulnerable to environmental fluctuations - therefore targets for rare insects should be an order of magnitude larger than for vertebrates

  31. Plants With a median population size of 119.5 individuals, plants have a low probability of survival or recovery Presence of seed banks may increase survival prospects for many of these plants, but there is no data on seed banks

  32. Critics of the ESA have questioned whether the distinction between threatened and endangered taxa has any biological basis Wilcove et al.’s study shows that in general endangered species are rarer than threatened species

  33. Vertebrate animals listed as endangered had significantly fewer individuals than those listed as threatened (Median 407.5 versus 4161) With no significant differences in number of populations (2 each)

  34. Sample size was inadequate to compare threatened and endangered invertebrate animals. When invertebrate and vertebrate animals were combined, animals listed as endangered had significantly fewer individuals than those listed as threatened (515 versus 4161) - with no differences with respect to population numbers

  35. Endangered plants had fewer individuals (Median 99 versus 2500) and fewer populations (Median 3 versus 9) than threatened plants

  36. Their results suggest why only a few species have recovered to the point where listing was no longer necessary - not protecting imperiled taxa soon enough! Include the Brown Pelican, Bald Eagle, Whooping Crane, Peregrine Falcon, Grizzly Bear, American Alligator, Western Lakes Gray Wolf, MN Gray Wolf, and the California Gray Whale

  37. Going back to the issue of the likelihood that we can help the species in question (in this case allocate resources), the U.S. Fish and Wildlife Service also ranks species on a scale of 1 to 18 for determining recovery actions The ranking is based (in decreasing order of importance) on the degree of threat, recovery potential, taxonomic distinctiveness and conflict with economic alternatives

  38. Delisting a Species Grizzly Bear – 3/29/07 http://www.fws.gov/policy/frsystem/1999rules.cfm?date=09&doc_type=proposed Monitoring 5-Years Post