Title: ESM 211 Applied Population Ecology
1ESM 211 Applied Population Ecology
- Fall 2006
- Bruce Kendall
- 4514 Bren Hall
- x7539 kendall_at_bren.ucsb.edu
2Defining endangerment the US Endangered Species
Act
- A species is listed under one of two categories,
endangered or threatened, depending on its status
and the degree of threat it faces. An
endangered species is one that is in danger of
extinction throughout all or a significant
portion of its range. A threatened species is
one that is likely to become endangered in the
foreseeable future. To help conserve genetic
diversity, the ESA defines species broadly to
include subspecies and (for vertebrates) distinct
populations. (USFWS 2005, p. 1)
3Listing decision under the US ESA
- A species is added to the list when it is
determined to be endangered or threatened because
of any of the following factors - the present or threatened destruction,
modification, or curtailment of the species
habitat or range - overutilization for commercial, recreational,
scientific, or educational purposes - disease or predation
- the inadequacy of existing regulatory mechanisms
- other natural or manmade factors affecting the
species survival.
4Defining endangerment the IUCN Red List
- 7 categories
- Extinct (EX) Extinct in the Wild (EW)
- Critically Endangered (CR) Endangered (EN)
Vulnerable (VU) - Near Threatened (NT) Least Concern (LC)
- Classification into CR, EN or VU based on
quantitative criteria most restrictive of 5
5Red List Criterion A
6Red List Criterion C
7Red List Criterion D
8Red List Criterion E
9Population Viability Analysis
- PVA is the use of quantitative methods to predict
the likely future status of a population or
collection of populations of conservation concern
- Future status
- Threshold population size (perhaps zero)
- Trends in population size
10Logistics
- Roll
- Computer accounts
- Experiences
11Objectives understand the following
- population monitoring programs study design,
data collection, data analysis - how to design population models from qualitative
biological information - how to parameterize population models
- how to use the population model to project the
fate of the population under various management
scenarios, and identify management actions that
are most likely to be effective - how to cope with variability and uncertainty in
all of the above - how to link the output of population models to
management decision-making and social
optimization tools
12Term project
- The IUCN/SSC Equid Specialist Group
(http//www.iucn.org/themes/ssc/sgs/equid/) wants
to re-evaluate the status of the 7 wild equid
species (zebras, wild horses, wild asses) - I should be getting data within a couple of
weeks. - Working in teams, you will use the red list
criteria to assess the species. The final
product will include the formal assessment
summary as well as a document that describes your
analyses in detail.
13Term Project backup plan
- Analyze some population data and to perform a
PVA, using whatever techniques are appropriate to
the problem at hand. - Prepare a monitoring plan.
14Assess extinction risk of single population
- Mark Shaffer (Ph.D. student at Duke) Will
Yellowstone grizzlies have 95 chance of
surviving to different times in the future? - 100 years yes
- 300 years no
- Influenced mgmt of GYE (less clear
cutting mining) - Forestalled premature removal from ESA
threatened list - First quantitative PVA (1978)
M.L. Shaffer (1981) BioScience 31131-134
15Compare relative risks of multiple populations
- 10 of 11 local populations of Northern Spotted
Owl are declining - Which salmon populations can be preserved with
limited funding? - Allows triage
- Some populations will be OK on their own
- Some populations will be impossible to save
- Focus on the rest, where conservation efforts
will make a difference
E.D. Forsman et al. (1996) Demography of the
Northern Spotted Owl F.W. Allendorf et al. (1997)
Conservation Biology 11140-152
16F.W. Allendorf et al. (1997) Conservation Biology
11140-152
17Analyze synthesize monitoring data
- Are gray whale data sufficient to merit
delisting? - Species delisted in '94, after 17
surveys - Survey costs 60,000
- Could have been delisted in 1978,
after 11 surveys
L.R. Gerber et al. (1999) Conservation Biology
131215-1219
18Identify key life stages or demographic processes
as management targets
- What life stage of sea turtles is most
susceptible to management intervention? - Improving hatchling survival on beaches helps,
but is not sufficient - Juvenile adult survival needs to be improved
- Analysis led to implementation of TEDs
D. Crouse (1987) Ecology 681412-1423
19Determine reserve size to achieve desired
protection
- How large do parks in semi-arid Africa need to be
to preserve elephants in the face of various
drought projections? - Large population size is good
- 3.1 elephants per mile2
- Need 500 mile2 for 99 chance of persisting
1000 years
P. Armbruster R. Lande (1993) Conservation
Biology 7602-610
20Determine number of individuals to release to
establish new pop
- Tradeoff between number of new populations and
size of each - Latter effects probability that each succeeds
- What is the value of continuing to add new
individuals after initial release? - Capercaillie in Scotland for 95 probability of
surviving 50 years, need initial release of - Without supplementation 60 individuals
- With 2 individuals added every 5 years 10
individuals
K. Marshall G. Edward Jones (1998)
Biodiversity and Conservation 7275-296
21Set limits on harvest or take
- How many (and what stage) individuals can be
taken before pop declines? - Harvest (e.g., black bear, wild ginseng)
- Bycatch
- Habitat destruction
- Particularly relevant for setting levels of
allowable take under ESA and HCP
22Determine how many ( which) populations needed
for species persistence
- Furbishs lousewort grows in small populations
on banks of single river in Maine - Local populations frequently go extinct through
ice scouring - Protecting only extant populations will ensure
eventual extinction - Must also manage other sites to enhance
opportunities to colonize new populations
E. Menges (1990) Conservation Biology 452-62
23Approaches to PVA
- Count-based PVA
- Uses census data
- Assumes all individuals identical
- Demographic PVA
- Incorporates information about vital rates
- Can include population structure
- Spatially explicit PVA
- Incorporates migration and colonization
24Approaches to PVA
Biological realism
Data requirements
Bias
Precision
25Further Reading
- Books
- Analysis and Management of Animal Populations
(2002 Williams et al.) - Population Viability Analysis (2002 Beisinger
McCullough, eds.) - Quantitative Methods for Conservation Biology
(2000 Ferson Burgman, eds.) - Species Conservation and Management Case Studies
(2004 Akcakaya et al., eds.)
- Journals
- Biodiversity and Conservation
- Biological Conservation
- Conservation Biology
- Ecological Applications
- Ecology and Society
- Endangered Species UPDATE
- Journal of Wildlife Management
- Natural Resource Modeling
26References
- USFWS. 2005. Listing a Species as Threatened or
Endangered. Online document, available at
http//www.fws.gov/endangered/listing/listing.pdf.
Accessed 1 Oct. 2006.