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P
opulation viability analysis
(PVA), or extinction risk
assessment, is a process
used to estimate the probability
that a population of a target species
has the ability to sustain itself for
a specific time, be it 10, 30, or 100
years. A key feature of PVA is the
definition of minimum viable
population sizes and minimum
habitat areas—information which
can then inform decisions on
conservation priorities.A tool for conservationists
PVA combines both statistics and
ecology to calculate the fewest
organisms required for a species
to survive long-term in its preferredIN CONTEXT
KEY FIGURE
Mark L. Shaffer (1949–)BEFORE
1964 The IUCN publishes its
first Red List of threatened
mammal and bird species.1965 In The Destruction of
California, ecologist Raymond
Dasmann charts the rapid loss
of flora and fauna in the state.1967 The Theory of Island
Biogeography by Robert
MacArthur and Edward O.
Wilson explores island patterns
of immigration and extinction.AFTER
2003 Population viability
analysis (PVA) of the Fender’s
blue butterfly is used to guide
conservation in the US.2014 PVA studies in the
Sonoran Desert, US, help
assess the response of birds
and reptiles to climate change.PREDICTING
A POPULATION’S
SIZE AND ITS
CHANCES OF
EXTINCTION
POPULATION VIABILITY ANALYSIS
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