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ZooNooz Article - december 2004
The mating game
Conserving threatened and endangered species and promoting sustainability calls for a cooperative regional approach, explains JANE MUNDY.
Photographs Jeff Grant, Jo Nevin, Annette Petersen and Leonie Saville
The family of Cotton-top Tamarins
scampering through the branches
and vines of their island home at
Taronga Zoo looks just like any other
family - eating, sleeping, playing and,
every now and again, mating. But
this group is special. Its members
have been carefully selected to
ensure, as much as possible, not only
that their numbers will be increased
in captivity but also that the vital
genetic diversity of the group will be
optimised.
The individual animals in the
group were chosen after analysing
the genetic make-up of all Cotton-top
Tamarins kept in Australasian zoos
and calculating the 'spaces' available
throughout the region in which to
house them.
Black-and-white Ruffed Lemurs |
This exhaustive process is part of
the work of the Australasian Species
Management Program (ASMP), the
species management arm of the
Australasian Regional Association
of Zoological Parks and Aquaria
(ARAZPA), through which species
management and collection planning
recommendations are generated for the 40-plus zoos in our region.
Once a species is selected for regional management, a 'studbook' is developed which documents genetic and demographic data about each animal of that species in the region.
Forming the backbone of this
network are Taxon Advisory Groups
(TAGs), whose role is to advise zoos
on which species to hold and in what
numbers. The principle behind their
management decisions is to increase
captive population size and thus
reduce the need to collect animals
from the wild or to import new
animals to the region to supplement
existing populations. The curators of
each zoo represent their organisation
on these TAGs and ensure that
their zoo's interests are represented
and that recommendations are
implemented.
Cotton-top Tamarins |
Species considered suitable for
regional management are selected
on the basis of need. High on the list
are species that are threatened in the
wild or on the CITES (Convention
on the International Trade of
Endangered Species) threatened
or endangered list. Others with
priority include: species native to
the region; species for which zoos
have husbandry and reproduction
experience; and species that play
a key role in their habitat. Some
species which are relatively common
in the wild and in Australasian zoos
may also have regional management
plans to ensure that their genetic
material is maximised in the overall
zoo population. Most breeding
programs aim to retain at least 90%
of genetic material over a 100-year
period, and any planned mating must
contribute to this target.
Black-and-white Ruffed Lemurs are another species, listed by CITES as endangered and threatened with extinction, whose future in part depends on effective captive management strategies.
Once a species is selected for
regional management, a 'studbook'
is developed which documents
genetic and demographic data about
each animal of that species in the
region. Each studbook is maintained
by a 'Studbook Keeper' or 'Species
Coordinator' - part genealogist part
detective - whose work is overseen
by the relevant TAG.
Like a family tree, a studbook
traces each animal held in the region
back to its wild founders and shows
who is related to whom, and how.
Understanding the relationships
between all the animals held, both
currently and in the past, helps inform
critical decisions about which animals
should breed and which should not.
This is to maintain a high degree of
the genetic variation of the original
wild population, minimise the chances
of inbreeding and maintain a strong,
healthy captive population.
The Cotton-top Tamarin
Studbook Keeper is Amanda Embury,
from Melbourne Zoo. Under her
management, zoos throughout
Australasia now hold a healthy
captive population of 75 Cotton-top
Tamarins, well exceeding the TAG
target of 50.
Approximately 22 Taronga and
Taronga Western Plains Zoo staff are Studbook
Keepers/Species Coordinators and,
like Amanda, they undertake these
responsibilities voluntarily in addition
to their regular zoo work.
Species which are the subjects of management programs are regularly exchanged with other zoos within the program in order to prevent inbreeding.
Black-and-white Ruffed Lemurs
are another species, listed by CITES
as endangered and threatened
with extinction, whose future in
part depends on effective captive
management strategies. The
last two genetically viable
pairings of Black-and-white
Ruffed Lemurs (at Melbourne
and Dubbo) have so far failed
to produce offspring, so with
an aging and closely related
population now remaining in
Australasia, Studbook Keeper
and Species Coordinator,
Suzy Barlow (formerly of
Taronga Western Plains Zoo, now Zoos
Victoria) recommends that new animals be imported urgently.
Species which are the subjects
of management programs are
regularly exchanged with other
zoos within the program in order to
prevent inbreeding. Sometimes this
means that a zoo may need to hold a
bachelor group of animals, enabling
the regional population to continue
to breed whilst animals currently
not required for breeding can be
held in reserve. This often happens
in populations in which a male has
a harem of females and where all
other males born in the group, upon
reaching sexual maturity, may not
immediately have a breeding group to
be transferred to. Zoos may then hold
a small group of bachelors awaiting
placement in a breeding situation.
Cotton-top Tamarins
At the end of the day, however,
these soundly-based scientific
principles of genetics will count for
nothing if the essential chemistry
between two animals is just not
happening.
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