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Why prioritise conservation efforts?

- ideally would protect everything but non pragmatic to divide attention equally between all species

- humans are unevenly distributed, species near dense human populations experience more threats

- some species are more sensitive


What are the four main ways of setting conservation priorities?

- taxonomically unique species
- keystone species
- umbrella/flagship/indicator species
- rare/threatened species


What is taxonomic distinctiveness?

- formalised by Vane-Wright (1991)
- Distinctiveness (D) = max branches from the root / the number of branches from root for species

- modifications added

- May's distinctiveness: max number of descendants on the path from the root / number of descendants on the path from the root for the species

- terminal branch length

- future distinctiveness

- combine w other metrics like abundance


Why use to taxonomic distinctiveness to set priorities? Difficulties?

- sound and intuitive principle
- sole family representatives have greater conservation importance as represent more genetic (and often functional) diversity


- requires detailed taxonomic knowledge
- only works for some groups


Taxonomic distinctiveness example:

- kagu vs green-backed white-eye

- both kagu and green-backed white-eye endemic to new caledonia


- kagu only member of Rhynochetidae genus
- green-backed white-eye from genus with 75 species (Zosterops)


What is a keystone species?

- species whose impact on the community is large and large relative to their biomass i.e not just dominant species

- Community important index (CI): change in community trait/change in focal species biomass
- CI > 1 = keystone species


What is an example of a keystone species?

- starfish

- upon removal of starfish system collapsed from 15 - 8 species
- starfish are predators that prevent competitive dominance & exclusion at lower trophic levels


What are the problems with using keystone species to set priorities?

- limited in use assigning priorities
- many keystone species only identified anecdotally
- robust identification difficult, often requires removal experiments
- a few non-keystone species can have same significance as one keystone species


What are umbrella/flagship/indicator species?

- all share basic concept that protecting a single species will help protect others
- characteristics of focal species differ


What is an umbrella species? Example?

- species that require large area for conservation
- protect other species with similar habitat requirements
- tend to be large vertebrates

e.g. endangered Saiga antelope
- declined 95% between 1950 and 2010
- critically endangered
- shared threat with other species: habitat destruction


What is a flagship species? Example?

- charismatic species used to promote conservation of a region/habitat
- can require small or large areas
- e.g. seahorse home range of 10m2


What are problems with flagship species driven priorities?

- useful concept
- can divert resources away from more effective conservation species for focal habitat
- implies focal habitat is worth less without focal species


What is an indicator species?

- species with narrow ecological tolerance
- therefore found only under certain set of conditions
- help to protect indicated habitat
- no specific area requirement


How useful is setting priorities by umbrella/flagship/indicator species?

- important concepts
- facilitate conservation but not problem free
- used in isolation will not generate adequate protection of other species


What is a rare species?

- Rabinowitz 1981: there are 7 different kind of rarity
- relate to intersections between geographic range size, habitat specificity and population sizes

- some species are naturally rare
- different types of rarity requires different conservation action
- rare species aren't always threatened


What is an example of a non-threatened rare species?

- Seychelles small day gecko
- endemic and v small geographic range
- 50,000 individuals, v high density
- can survive in agricultural and urban areas as well as natural rainforest habitat


What are examples of a common species becoming extinct?

- rocky mountain grasshopper
- went from abundant to extinct within 30 years, probably due to loss of breeding habitat

- passenger pigeon
- 3-5B individuals when europeans discovered america circa 1500
- 25-40% north american birds
- extinct in 1914


Why protect common species?

- american chestnut

- functionally important
- not exempt from extinction

- american chestnut
- nutrient rich leaves decay rapidly
- was abundant on eastern seaboard
- fungal disease decimated population by 95%
- majorly altered nutrient cycling and freshwater invertebrate assemblages


How are species prioritised by extinction threat?

- population viability analysis

Ideal: Population Viability Analysis (PVA)
- based on detailed up to date demographic data: population size, birth rate, death rate, how these vary with environment
- impractical for most species


How are species prioritised by extinction threat?

- IUCN red list

- International Union for the Conservation of Nature
- started in 1960
- 40,000 species now assessed
- all birds, mammals & amphibians & partial assessments for other taxa
- global assessments underway for fish, corals, and plants


What are the aims of the IUCN red list?

- classify threats to assign priorities & measure conservation progress
- consistent when used by different people
- improve objectivity through clear guidance
- facilitate cross-taxa comparisons
- transparency: give people using the lists a better understanding of the classification process


What are the IUCN red list categories?

- evaluated or non evaluated

if evaluated
- adequate data vs data deficient

if adequate data
- extinct, extinct in the wild, threatened, near threatened, least concern

if threatened
- critically endangered, endangered, vulnerable


What do the IUCN threat categories mean?

critically endangered
- extremely high risk of becoming extinct in the wild

- very high risk of becoming extinct in the wild

- high risk of becoming extinct in the wild

near threatened
- close to qualifying for above, or likely to qualify for above in near future


What are IUCN evaluations based on?

- range sizes

- population sizes
- number of populations: number of distinct
groups with little demographic or genetic exchange
(less than one individual/gamete per generation)

- whether populations are severely fragmented: severely fragmented populations - most
individuals found in small and relatively isolated

- trends in the population

- whether populations fluctuate extremely


What are the difficulties associated with identifying range size for the IUCN redlist?

- extent of occupation (area within range boundary) vs area of occupancy (occupied grid cells)
- measure different properties
- area of occupancy varies with spatial scale


What are the difficulties associated with identifying population size for the IUCN redlist?

- population size: number of mature individuals capable of reproduction
- but sex ratio/biases must be considered
- reintroduced individuals only counted after having successfully bred


What are the difficulties associated with identifying population number/fragmentation for the IUCN redlist?

- typically has to use habitat distribution data as little information on links between populations


What are the difficulties associated with identifying population trend for the IUCN redlist?

- over ten years or 3 generations

- observed, inferred or suspected in the past OR
predicted in the future

- e.g. endangered if decline > 50% and causes
unknown, continuing or not reversible

- often no direct data on population trend

- can use data on trends in habitat loss – if good
data on habitat selection available


What are EDGE species?

- evolutionarily distinct and endangered
- priority