Conservation Biology of Single Species

1
Conservation Biology of Single Species

• Choice of Species so many endangered, so little
  money

2
Statement reflects the number of endangered
species listed (1,967 U.S. and Foreign) and the
amount of money budgeted for administering the
Endangered Species Act (37 million in 1991
around 181 million 2011)http//www.fws.gov/budge
t/2011/PDF20files20FY201120Greenbook/03.20Budg
et20At20A20Glance.pdf
3
4 / 14 / 2011 Endangered Species Act

Species Recovery
Endangered Threatened Total
Plans Mammals 325
34 359 60 Birds
271 29
300 85 Reptiles
79 40 119
38 Amphibians 22
11 33
17 Fishes 84
67 151 101 Snails
26 11
37 29 Clams
65 8
73 70 Crustac 19
3 22
18 Insects 54
10 64
40 Arachnids 12
0 12 12 Plants
614 145
759 638 TOTAL
1,602 365 1,967
1,139
(594)
4
Endangered Species by Statehttp//www.endangereds
pecie.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 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 892 species - trade prohibited
• Appendix II 4359 animals, 28674 plants trade
  regulated
• Appendix III 161 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/opendocs.cfm
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 Acts 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
101-1000
gt100,000
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
gt100,000
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
gt25
Populations
27
Median Populations of Plants 4.0
Listed Taxa
0
1-5
6-10
11-15
21-25
16-20
gt25
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?d
ate09doc_typeproposed
Monitoring 5-Years Post