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APS271 Conservation Principles > what to prioritise? species level (lecture 3) > Flashcards

what to prioritise? species level (lecture 3) Flashcards

1
Q

Why prioritise conservation efforts?

A
  • 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
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2
Q

What are the four main ways of setting conservation priorities?

A
  • taxonomically unique species
  • keystone species
  • umbrella/flagship/indicator species
  • rare/threatened species
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3
Q

What is taxonomic distinctiveness?

A
  • 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
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4
Q

Why use to taxonomic distinctiveness to set priorities? Difficulties?

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

BUT

  • requires detailed taxonomic knowledge
  • only works for some groups
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5
Q

Taxonomic distinctiveness example:

  • kagu vs green-backed white-eye
A
  • both kagu and green-backed white-eye endemic to new caledonia
  • BUT
  • kagu only member of Rhynochetidae genus
  • green-backed white-eye from genus with 75 species (Zosterops)
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6
Q

What is a keystone species?

A
  • 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
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7
Q

What is an example of a keystone species?

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

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

A
  • 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
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9
Q

What are umbrella/flagship/indicator species?

A
  • all share basic concept that protecting a single species will help protect others
  • characteristics of focal species differ
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10
Q

What is an umbrella species? Example?

A
  • 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

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11
Q

What is a flagship species? Example?

A
  • charismatic species used to promote conservation of a region/habitat
  • can require small or large areas
  • e.g. seahorse home range of 10m2
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12
Q

What are problems with flagship species driven priorities?

A
  • useful concept
    BUT
  • can divert resources away from more effective conservation species for focal habitat
  • implies focal habitat is worth less without focal species
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13
Q

What is an indicator species?

A
  • species with narrow ecological tolerance
  • therefore found only under certain set of conditions
  • help to protect indicated habitat
  • no specific area requirement
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14
Q

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

A
  • important concepts
  • facilitate conservation but not problem free
  • used in isolation will not generate adequate protection of other species
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15
Q

What is a rare species?

A
  • 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
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16
Q

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

A
  • Seychelles small day gecko
  • endemic and v small geographic range
    BUT
  • 50,000 individuals, v high density
  • can survive in agricultural and urban areas as well as natural rainforest habitat
17
Q

What are examples of a common species becoming extinct?

A
  • 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
18
Q

Why protect common species?

  • american chestnut
A
  • 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
19
Q

How are species prioritised by extinction threat?

  • population viability analysis
A

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
20
Q

How are species prioritised by extinction threat?

  • IUCN red list
A
  • 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
21
Q

What are the aims of the IUCN red list?

A
  • 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
22
Q

What are the IUCN red list categories?

A
  • 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

23
Q

What do the IUCN threat categories mean?

A

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

endangered
- very high risk of becoming extinct in the wild

vulnerable
- high risk of becoming extinct in the wild

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

24
Q

What are IUCN evaluations based on?

A
  • 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
    subpopulations
  • trends in the population
  • whether populations fluctuate extremely
25
Q

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

A
  • extent of occupation (area within range boundary) vs area of occupancy (occupied grid cells)
  • measure different properties
  • area of occupancy varies with spatial scale
26
Q

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

A
  • population size: number of mature individuals capable of reproduction
  • but sex ratio/biases must be considered
  • reintroduced individuals only counted after having successfully bred
27
Q

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

A
  • typically has to use habitat distribution data as little information on links between populations
28
Q

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

A
  • 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
29
Q

What are EDGE species?

A
  • evolutionarily distinct and endangered

- priority

APS271 Conservation Principles (20 decks)

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