Towards Sustainable Population Management - Waza

WAZA magazine Vol 12/2011 11
Kristin Leus 1,2 *, Laurie Bingaman Lackey 3 , William van Lint 1 ,
Danny de Man 1 , Sanne Riewald 4 , Anne Veldkam 4 & Joyce Wijmans 4
Sustainability of European
Association of Zoos and Aquaria
Bird and Mammal Populations
Introduction
A rapid assessment of the sustainability
of bird and mammal populations
managed by the European Association
of Zoos and Aquaria (EAZA) as
European Endangered Species Programmes
(EEPs) and European Studbooks
(ESBs) was initiated in 2008, in
response to concerns arising from the
European Union (EU) bird import ban
triggered by avian influenza. There is
as yet no such blanket ban for mammal
populations, but we have already
experienced transport restrictions
for various groups of mammals in
response to disease outbreaks, such
as bluetongue, bovine spongiform
encephalopathy (BSE) and foot-andmouth.
All of this begs the questions
“are, or can, EAZA bird and mammal
populations be sustainable” and
“what do we mean by sustainable”?
1 European Association of Zoos
and Aquaria, Amsterdam,
The Netherlands
2 IUCN/SSC Conservation Breeding
Specialist Group Europe,
c/o Copenhagen Zoo,
p/a Merksem, Belgium
3 International Species Information
System, Eagan, MN, USA
4 Van Hall Larenstein University
of Applied Sciences, Leeuwarden,
The Netherlands
* E-mail for correspondence:
kristin@cbsgeurope.eu
Self-sustainability generally implies
that a population can remain genetically
and demographically healthy
without further importation. For the
time being, the “default” criterion
for genetic self-sustainability of zoo
populations is that the captive population
be able to maintain 90% of the
genetic diversity of the wild population
for 100 years without further
imports. The demographic factor is
equally important and is a precondition
for genetic sustainability. Genetic
diversity comes “wrapped up” in
living individuals. A population that is
losing individuals is therefore always
losing gene diversity – when the animals
are gone, the genes are gone.
Are EAZA bird and mammal populations
demographically self-sustainable?
Demographic self-sustainability
implies that, on average, the number
of births and hatches is as high, or
higher, than the number of deaths
(and, where relevant, exports). If
imports into the EU are becoming
(more) restricted, then we will have
to rely on births and hatches in EAZA
collections or high quality private
and/or non-EAZA collections in the
EU to counteract deaths and removals
of individuals from the population
for other reasons. This is easy to say
but hard to track. Although it is encouraging
that the number of EAZA
institutions joining the International
Species Information System (ISIS)
has rapidly increased over the years,
some zoos are not yet members; not
all zoos have entered all their data;
data are not always up to date; and
the origin of individuals is not always
clear. Analysing the EAZA data in ISIS
will therefore be time-consuming and
not always successful. We therefore
decided to evaluate the EAZA EEP
and ESB bird and mammal populations
by utilising the SPARKS studbook
databases. Furthermore, one
would normally expect that more of
the managed populations are selfsustainable
than are non-managed
populations.
»