Approaches to conservation

Approaches to conservation

1. In situ

   • Protecting species 'on site' in their natural environments
     • More than 20,000 protected sites globally
       • Limitations: - Areas too small to maintain pops of large animals, e.g. 80% African elephants outside of protected zones
         • - Uneven distribution globally: tend to be in poorer countries, therefore not representative of all habitats.
           • - Isolated from eachother and changes in distributions - natural or as result of climate change - not taken into account.
             • - Lack of practical application: Park boundaries, anti-poaching patrols et.
               • Inadequate c.0.5% oceans protected.
   • Research
     • Identification of cause of decline/threats
       • Enables implementation of most appropriate action
         • e.g. Australian Bandicoots - breeding high, but predation by cats issue.
       • Survivorship curve: type 1, 2, or 3?
         • [Image: http://www.nature.com/scitable/content/ne0000/ne0000/ne0000/ne0000/16372152/f1_rauschert.jpg] Figure 1 : Idealized survivorship curves In Type I survivorship, mortality rates are low until late in life. In Type II survivorship, a constant proportion of individuals die throughout the life cycle. In Type III survivorship, juvenile mortality is very high; individuals surviving past that initial phase have higher survivorship
     • Population variability analysis
       • Assigning priority
         • "Red Data Books" label species: extinct, extinct in wild, critically endangered, endangered, near threatened, least concern, data deficient, not evalu
           • Allows for identification of where conservation is required.
       • Species diversity indices analyse species richness and relative abundance, helps identify where conservation is required.
         • rarity doesn't necessary equal under threat- rarity natural sometimes
   • Interventions
     • Habitat protaction and management
       • Protective legislation- African elephant: Placed on CITES Appendix 1 making ivory trade illegal
         • Populationhad declined by 85& '73-'87, but mostly revived due to decline in poaching.
     • Restoration ecology
       • Reducing pollutants, planting roughage for nests/steams for spawning.
         • Negative feedbacks: benefitting one species to detriment of other.
     • Eradication/prevention of invasive species.
     • Re-introductions: deliberate movement of individuals back into natural range - can be linked to ex-situ breeding mehtods.
       • Golden lion Tamarin Monkey: Bred in captivity when numbers dropped to c.100. Re-released in wild (Brazil) and now 800. Also education for local people
     • Red howler monkey, French Guiana
       • Translocation: original area flooded so some individuals removed and released at another similar site
         • Successful, but many examples not succesful due to competition, predation, pathogens etc.
       • Population reinforcement: Local hunting had reduced the local population density of howler monkeys at release site.

2. Ex situ

   • Should always play a secondaty role to in situ.
     • Compliments in situ conservation with abilty to re-introduce animals bred in captivity.
       • Captive breeding - ethical issues. But living collections may provide last refuge for endangered species which only exist in captivity.
         • Advantages: reintroductions, reduced infant mortality, less need for translocation, maximising genetic variability through selective breeding.
           • Disadvantages: May threaten wild pop., ecological requirements not met, limits of space, loss of genetic diversity, hybridisation, human imprinting
         • Failure: Sumatran Rhino: 40 taken into zoo for breeding, 20 died and none were born over 17yrs.
   • "Living collections" e.g. zoo's, aquariums, botanic gardens.
   • "Banking biodiversity" e.g. Kew seed banks (1.5 billion seeds), 'Frozen Ark' cryogenic freezing of animal cells.
   • Red Kite: re-introduced to England from Europe after almost becoming extinct due to hunting and habitat depletion in 19th century.