When Is A Species Endangered And
Where Should Conservation Efforts
Be Placed
Sam Hopkins
Biodiversity and Conservation
Biology
Available at http://planet.uwc.ac.za/nisl/Eco_people/Presentations/
An Optional
Graphic
can go here
What makes species vulnerable to
extinction 1

Criteria taken from Cox (1997)

Large species with a low reproductive potential

Species with a high economic value

Species at the end of a long food chain

Species restricted to local, insular habitats


Species that are specialised for habitats, breeding sites
or food
Migratory species
When is a species endangered?

This is a matter of much discussion

Certain criteria are constructed by the
organisations that need to categorise the
extinction risk of species
When is a species endangered? The IUCN criteria 2

IUCN stands for the International Union for the Conservation of
Nature and Natural resources

They state that the extinction rate is 1,000 to 10,000 times higher
than what it should be

They have 9 categories

Extinct

Extinct in the wild

Critically endangered

Endangered

Vulnerable

Near threatened

Least concern

Data deficient

Not evaluated
When is a species endangered?
The CITES criteria 3

CITES stands for The Convention on International Trade in
Endangered Species of Wild Fauna and Flora

Signed by 169 countries

Species are placed into 3 appendices
I.
Species threatened with extinction
II.
Species not threatened but controlled to stop then
becoming threatened
III.
Species protected by one country and has asked
CITES to control trade
Is it our duty to conserve? 1

This is a personal question

Today's society generally has a pragmatic- utilitarian ethic.
This means that human success is important and
technology will answer any future problems when
resources run low. It sees humans and a few animals (pets,
whales, dolphins etc.) as primarily important and everything
else of secondary importance

At the other end of the scale is the ecocentric ethic where
the interests of humans and non-humans are treated
equally on some kind of scale, where the lowest end of the
scale is everything's right to exist to the highest end which
is some kind of satisfaction

Is it also our duty to preserve things for future generations?
Is it our duty to conserve? 4

Conservation costs money



Figures so far in America

Northern Spotted owl, $9.7 million

Grizzly bear, $5.9 million

Florida Panther, $4.1million
In the UK if all the plans for conservation were carried
out it would cost 800,000 pounds per year for over 15
years
Is it better to put conservation areas to use in agriculture or
housing?
What to conserve?

As you have seen from the past few lectures, the world is in
an extinction crisis at the moment and it is not possible to
conserve everything

The question is, what to conserve?

Do we conserve single large species that in turn will
conserve large amounts of habitat for other species?

Do we conserve the genetically distinct animals such as the
Tuatara?

Do we conserve ‘hotspots’ of land that will conserve the
most numbers of species?

Do we leave species to go extinct as extinction is a natural
process?
Do we conserve single large species that in turn will
conserve large amounts of habitat for other species?

It is estimated that to conserve a viable elephant population
for 1000 years it would take 1000 miles 2 of land 5

In conserving this piece of land many other species would
be conserved as well

However this may not always be the ideal land for
conserving large numbers of endangered species if it is the
elephants alone that are being concentrated on

On the positive side, people are more likely to give money
to save a charismatic creature like an elephant than a snake
or beetle
Do we conserve the genetically
distinct animals such as the tuatara?

When the Tuatara was discovered it was
thought that it was a lizard with an odd skull 6

Now been placed in a group equal to the Squamata (lizards
and snakes), Rhynchocephalia 7

The Rhynchocephalia includes several extinct taxa and the
two remaining species alive today

Was once widespread but now found only on small islands
off New Zealand 8

Has declined due to mammal introduction 8

Is it important to keep these animals alive or should they
have gone extinct years ago with all their relatives?
Do we conserve
‘hotspots’ of land that
will conserve the
most numbers of
species?

One theory suggests that we should
conserve hotspots of biodiversity

Identify areas with increased species
richness, high numbers of endemic
species and high numbers of rare species9
Do we conserve ‘hotspots’ of land that will
conserve the most numbers of species?
- argument for 10

Areas that are conserved for their large species
diversity will probably have a complex habitat
allowing large amounts of diversity of other taxa
to be conserved as well

Reyers et al. (2000) states that areas that are
important to the conservation of one taxon will
conserve high levels of diversity of other taxa 11
Do we conserve ‘hotspots’ of land that will
conserve the most numbers of species?
-argument against

However, often there is a low correlation between high
species richness and high endemicity 9

Hotspots for different species rarely overlap 11

Eg. Reyers et al. (2000). Found that species richness
hotspots for vertebrates and invertebrates are not the
same10

Hotspots may miss a species vital to conservation10

Examples of species that are endemic to an area but not
living in a species rich area 9

Pocket gopher (Pappogeomys zinseri)

Perote ground squirrel
Do we leave species to go extinct as
extinction is a natural process?

The number of species that have become extinct through
time is almost equal to the number of originations of
species 12

Darwin saw extinction as a process of natural selection 12

This is more a question of how humans see themselves
fitting into nature

Are humans part of nature and therefore everything we do
is also natural?

Or are we above nature and it is ours to do what we want
with
Conclusions

This is a difficult topic to draw conclusions from

There are many different aspects that need contemplating
and answering and it is a personal viewpoint

The general public’s view is often different from the
scientific community’s view

As an answer as to what to conserve, Ceballos et al (1998)
suggest a scale of priority where highest efforts are placed
in conserving endangered species followed by nonendangered species with a small distribution with the
lowest efforts being given to species that survive well with
humans 9

They do not state how a species is considered endangered
and this approach needs much research to establish what
is at risk
References
1.
Cox, G. W. (1997) Conservation biology. Pp 287-296
2.
IUCN. An IUCN overview. [cited 2006 Jul 10] Available from: www.iucn.org/en/about
3.
CITES. What is CITES [cited 2006 Jul 10] Available from: www.CITES.org/eng/disc/what.shtml
4.
Spellerberg, I. F. (1996)Conserving biological diversity. In Conservation Biology. Pp 25-31
5.
Armbruster, P. and Lande, R. (1993) A population viability analysis for African Elephants (Loxodonta
africana): How big should reserve be? Conservation Biology 7: 602-610
6.
Bogert, C. M. (1953). The Tuatara: Why is it a lone survivor? The Scientific Monthly 76: 163-170
7.
Pough et al. (2001) Herpetology 2nd Ed.
8.
Cree et al. (1995). Reproduction of a rare New Zealand reptile, the Tuatara Sphenodon punctatus, on rat
free and rat inhabited islands. Conservation Biology 9: 373-383
9.
Ceballos, G. et al. (1998). Assessing conservation priorities in mega diverse Mexico: Mammalian diversity,
endemicity and endangerment. Ecological Applications 8: 8-17
10.
Reyers, et al. (2000). Complementarity as a biodiversity indicator strategy. Proceeding: Biological Sciences
267: 507-513
11.
Dobson et al. (1997) Geographic distribution of endangered species in the United States. Science 275: 550553
12.
Raup, D. M. (1994). The Role of Extinction in Evolution. Proceedings of the National Academy of Sciences
91: 6758-6763