Chapter 37: Ex-situ conservation of wild pigs and peccaries433
the popularity contest. Among the peccaries the most numerous
species held is the collared peccary (Pecari tajacu). In both AZA
and EAZA the TAGs are recommending a gradual shift of this
species to the Chacoan peccary as this latter species becomes
more available and requires more space. In the meantime insti-
tutions with collared or white-lipped (Tayassu pecari) peccaries
should consider supporting the implementation of the conser-
vation strategy recently developed for the Chacoan peccary
(Altrichter et al. 2016).
While replacement of non-threatened species with threat-
ened species may not be straightforward, it is imperative that
zoos follow through on their conservation breeding commit-
ments for those taxa that need it. In the meantime, options
should be explored to better use the non-threatened species to
rally conservation support and carry conservation education
messages for their more-threatened cousins, or indeed other
threatened taxa in similar habitats/locations.
General Challenges
As indicated above, the breeding programmes for some of the
threatened species such as the Visayan warty pig, the Sulawesi
babirusa, and the Chacoan peccary are looking for extra hold-
ers, and replacing non-threatened species with a threatened one
is not always a straightforward swap. These programmes are
therefore often on the lookout for extra holders, and run into the
challenge of their species not being particularly handsome or
colourful and having a knack for turning any landscaped enclo-
sure into a moonscape in five easy minutes. Nevertheless, the
zoo-going public is often attracted to pigs, no matter their exter-
nal appearance, because of their high levels of activity and social
behaviour. During the last decade or so, zoos have also become
more creative in trying mixed-species exhibits, for example with
rhinos (Figure 37.2), giraffe (Figure 37.4), okapi, large antelope,
cattle, deer, etc. Given a suitable enclosure size and design, these
combinations provide very attractive exhibits and provide solu-
tions for housing single-sex groups.
Given the relatively moderate to high fecundity of wild pigs,
populations can grow very quickly, and in order to keep them
stable at a certain size only a limited number of females can be
producing within a given year. Whether the populations have hit
space limitations, or have reached their target size, population
managers are struggling to find the best methods to limit popula-
tion growth for their species. There are two general approaches:
preventing the production of ‘unwanted’ individuals (through
permanent surgical methods, reversible contraception, separa-
tion of sexes, or removal of environmental conditions required
for breeding) or dealing with ‘unwanted’ individuals after they
have been produced (by transferring them to institutions out-
side the population or by using a breed-and-cull approach). No
method is perfect for every species, for every individual of the
same species or for every circumstance in the zoo/programme,
etc., and many factors must be considered when deciding which
method is appropriate for a particular circumstance (species,
individual age, health, genetic importance, reproductive status,
efficacy and safety of the method, degree of reversibility, method
and frequency of delivery, availability and cost, behavioural
and social group ramifications, culture/value systems/ethics
of the human community, consequences of potential loss of
future reproductive potential, etc.) (Asa & Porton 2010). Within
AZA and EAZA, breeding programme managers can make
use of the databases and advice of the AZA Reproductive
Management Center (www.stlzoo.org/animals/scienceresearch/
reproductivemanagementcenter/) and the EAZA Group on Zoo
Animal Contraception (www.egzac.org/), that gather published
information and experiences from zoos within their regions.
However, for wild pigs and peccaries, much information and
experience is still to be collected. In addition, discussions with
population managers and anecdotal reports (e.g. Rademaker
et al. 2016) suggest that there may be an element of ‘use it or lose
it’ (Penfold et al. 2014) at play, whereby females that have not had
the chance to breed for a while have a lower chance of doing so
later. With some species, such as babirusa, there is the impres-
sion that if a male and female are left together as a pair for a
prolonged period of time, breeding probability decreases. These
issues too require systematic, scientific investigation.
For wild pigs or peccaries that are held outside of their
range countries and/or cannot be fed natural food items, diet
and nutrition presents another area of challenge. Often either
a ‘historical trial and error approach’ has led to current diets
being fed, or domestic pigs (or at best Eurasian wild pigs) are
taken as the model species to devise diets for their wild coun-
terparts. However, many of the wild pig species have more spe-
cialized dietary habits in the wild and/or gastrointestinal tracts
that deviate from the ‘domestic pig model’ (Leus & Macdonald
1997). The result is that many wild pigs are fed inappropriate
diets, which may also have repercussions for their reproductive
abilities – for example, obese pigs may have reduced breeding
potential (Leus & Macdonald 1997; Leus et al. 2001).Opportunities
A not-to-be-underestimated side effect of managing ex-situ pop-
ulations of wild pigs and peccaries for conservation or exhibit is
the opportunity to gather biological information on species that
are often little known and barely studied in the wild. For exam-
ple, during the species conservation planning workshop for the
Chacoan peccary, many of the input parameters required for the
population viability analysis model were unknown or uncertain
for wild populations and information from the captive popula-
tions provide a basis to develop best-guess scenarios and sen-
sitivity testing (Leus et al. 2016b). Similarly, very little natural
history and basic biological information was or is known for wild
pygmy hogs, Visayan warty pigs, Javan warty pigs, and babirusa,
and basic data and observations recorded in captivity can bring
important and/or interesting new information, such as age of
sexual maturity, litter size, interbirth interval, longevity, social
behaviour, etc. (e.g. Oliver et al. 1997). Observations on captive
babirusa in Indonesian zoos showed that male babirusa in the
highest stages of agonistic interactions will stand on their hind
legs and box, that individuals of either sex may stand on their
hind legs to browse leaves from trees (Macdonald & Leus 1995),
and that males scent-mark loose earth by performing plough-
ing behaviour (Leus et al. 1996). While there were hints of babi-
rusa standing on their hind legs in eighteenth-century literature
(Meijaard et al. 2016), these behaviours were not properly.03913:02:26