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Pigs, Peccaries and
Hippos Status Survey and Action Plan (1993) Introduction The Old World pigs and their New World analogues,
the peccaries, are important to people. Hippos are also important but, being
(spectacularly) more specialized, much less so. Nonetheless, the arrival of
human settlers on Madagascar is implicated in the extinction of up to three
species of endemic hippopotamuses in the last one and a half millennia
(Grubb, this vol., section 4.1). Elsewhere human exploitation of the
suiformes dates back for tens of thousands of years. In many parts of the
world, wild pigs have long constituted the most commonly eaten large animal.
The earliest human remains (c. 40,000 yrs. BP) in the Niah Caves of Sarawak
(Borneo) are associated with large numbers of bearded pig (S. barbatus) bones
(Cranbrook, 1979), and recent studies of the economy of hunted species in
this country have demonstrated that this species is still by far the most
important game animal (Caldecott and Nyanoi, 1985). Pigs were also amongst the first species to be
domesticated, and it is now certain that this happened in several different
places and times with different (local) progenitors. Most of these
progenitors were regional variants of the Eurasian wild pig (Sus scrofa) but,
as Groves (1981) revealed, the Sulawesi warty pig (S. celebensis) has also
been domesticated, and its purebred, hybrid and feral derivatives are still
hunted and husbanded in various parts of South-east Asia and the Papuan
Realm. In these regions, in particular, the economic importance of wild and
domestic pigs led inevitably to their being interwoven with the cultures of
the people who depended upon them. Surviving examples of these 'pig cultures'
are still to be found amongst some tribal groups in these areas, and it is
apparent that pigs are as fundamental to the integrity and economy of these
societies as cattle are to other, comparable societies in the drier regions
of the Indian Subcontinent and Africa. Being highly adaptable, more prolific and more
suited to backyard and small-scale commercial husbandry, pigs are also more
abundant and more widely distributed than other hoofstock and they are still
amongst the most important of all domestic animals. In Asia alone, the annual
consumption of pork had exceeded 20 million tons per year by the mid-1980's,
an amount greater than the total consumption of all other domesticated
species put together (FAO, 1985). The importance of these animals as a basic food
resource was also reflected in their widespread carriage and dispersal during
the early transmigrations of settling peoples, who either released them to be
hunted whenever required for eating or who maintained them in varying states
of domestication. Their dispersal was continued by the later European
explorers, sealers, whalers, immigrant settlers and colonialists, and most
recently (and irresponsibly) by commercial and recreational hunters and game
meat producers; all of whom have transported and (whether accidentally or
deliberately) released founder stocks to form naturalized populations. As a
result, pigs are now one of the most widely distributed of all species, and
the diversity of wild and domestic, feral, hybrid, native and introduced
forms, has produced patterns of distribution and interrelationships of almost
unparalleled confusion. This complexity of forms is most apparent in
South-east Asia, where an inordinate number of taxa have been described in
the scientific literature. The challenge of unraveling their relationships
was taken up by Colin Groves, whose major reviews of Babyrousa (1980) and, especially, Sus (1981) are the basis for our present understanding of the
diversity and regional genetic variation in these genera. In clarifying the
affinities and distribution of innumerable naturalized populations, many of
which were erroneously recognized as valid taxa, Groves also helped to clear
the dross and provide a contextual framework for the interpretation and
weighting of other, conservation-related data. The current and equally important review of the
subgeneric taxonomy of the Afrotropical suids by Peter Grubb (section 4.1,
this vol.) has also provided an indispensable rationale for weighting future
research and conservation priorities amongst these animals. In this instance,
however, the prioritization process was greatly facilitated by the
simultaneous collection of questionnaire data on the present distribution and
conservation status of all suiform species from most (sub-Saharan) African
countries. In 1988/89, following a format similar to that devised by the
Antelope Specialist Group (East, 1988), approximately 600 questionnaires (one
questionnaire for each species of wild pig and hippo known or believed likely
to occur in each country) were sent to a total of 115 wildlife officials and
biologists in 42 countries. A total of 236 (39%) completed questionnaires
and/or copies of relevant reports, reprints and maps, were returned by 93
(81%) correspondents, with information from 34 (81%) countries. Analyses of
these data, together with information gleaned from a variety of other
sources, including Grubb's review, provide the basis for the 'action plan'
chapters for each species/genus in this volume. A similar questionnaire
survey is now being undertaken for the peccaries in Central and South America
and, in 1990, in collaboration with the Deer Specialist Group, a
questionnaire survey was initiated for all Eurasian and South-east Asian
suids. Unfortunately, however, only a very small number of completed
questionnaires have been returned to date, though the few data obtained from
these have also been incorporated in the relevant species' chapters. The obvious importance of utilizing both latest
taxonomic and recent field status data sets in the formulation of
conservation plans is exemplified by Grubb's (section 4.1, this vol.)
revelations about the warthogs of Somalia and northern Kenya. These animals
are diagnostically distinguished from all other living warthogs (P.
africanus) by a variety of dental and cranio-morphometric characters.
However, these characters are shared by another recent warthog, the so-called
'Cape' warthog (P. aethiopicus),
which was known only from the vicinity of Cape Province, where it is now
extinct. Clearly, the recognition of the survival of P. aethiopicus elsewhere, and the apparent isolation of the
Somali population, can only profoundly influence our perceptions about the
relative importance of these animals, in both scientific and conservation
terms. Unfortunately, the import of Grubb's review may be
bedeviled by bickering between the traditionalists and the revisionists or,
as with Phacochoerus, between neontologists and paleontologists, as to the
validity of the two species approach. This also applies to the separation of
the bushpig and the red river hog as two, distinct species, Potamochoerus larvatus and P. porcus, respectively. Neither of
these divisions is new, since both have been proposed by various earlier
authors, though never in the light of so comprehensive a re-examination of
available museum specimens as that undertaken by Grubb. Despite this, the
recognition of two species in each of these genera has already ruffled a few
traditionalist feathers, and it seems likely the debate will rumble on as a
futile distraction from the more pressing business of addressing the future
research and management requirements of these animals. This is not to suggest that Grubb's review, or those
of Groves (1980, 1981) before him, are the last word on the subgeneric
taxonomy of these animals. Taxonomy is at best an inexact science, and the
present subdivisions are no more than a logical reflection of current
understanding of the variation within these genera. By the same token, the
relative extent of variation within these or other genera, will not only
determine where the lines are drawn, but influence the taxonomic ranking
accorded to the various subgroupings. Thus, the distinction between species
and subspecies is frequently blurred and, in the absence of any precise
knowledge of the degree of genetic variation within the genus as a whole, and
an objective overview of that variation, it may become nonsensical to dismiss
'subspecies' as intrinsically less important than 'species'. These sentiments can be illustrated by the recent
'elevation' of two 'new' species of Sus,
both endemic to the Philippines. These are the Visayan warty pig (S. cebifrons) from the West-Central
Visayas Islands and the East Philippines' warty pig (S. philippensis) from Luzon, Mindanao and associated islands.
Following Sanborn (1970), both of these taxa were assigned to S. celebensis until Groves (1981)
reassigned them as endemic subspecies of S. barbatus. However, following the
acquisition of additional skulls and mandibles in 1990, Groves (1991)
suggested these were actually sufficiently distinct to merit full species
status; a view which has recently (too recently for the full results to have
been incorporated in this volume) been strongly endorsed by de Haan et al. (in press) on account of their
lower chromosome number (i.e. 36, as opposed to the 38 typical of other
members of the genus) and other cytological characters. The addition of these two species, together with at
least one endemic and one endemic subspecies of S. barbatus (i.e. ahoenobarbus
from Palawan and associated islands, and barbatus
from Tawi-tawi and Sibutu, respectively), makes the Philippines the second
most important country in the world (after Indonesia) for its diversity of
wild pigs. There may even be still more taxa awaiting description in the
archipelago. S. philippensis, for
instance, is currently regarded as monotypic, though the few adult
individuals which have been examined from the two, principal populations on
Luzon and Mindanao, appear morphologically distinct in some respects (e.g.
color and shape of the crest and mandibular warts, color of pelage on cheeks,
etc.), and these may be new subspecies. Theoretically, the wild pigs of
Mindoro should be closely related to those of neighbouring Luzon, though the
only specimen examined to date shares the same chromosome number (38) as
those from Palawan (de Haan et al.,
in press), which it also resembles more closely in appearance. Wild pigs have
already been extirpated on two (Tablas and Romblon) of the three islands in
the isolated Romblon Group, and although they are reported to survive on
Sibuyan, no museum specimens exist. This situation also applies to Masbate
and a number of other, relatively isolated islands where pigs are reported to
survive, as well as to Siquijor where they are now extinct (Cox, 1987;
Oliver, 1992; Oliver et al., this vol., Fig. 14). In any event, it is clear that much more work is
needed in countries like the Philippines, where we have only very recently
begun to obtain an understanding of the genetic diversity and future
management requirements of these animals. Moreover, some of this work is
undoubtedly urgent. Whatever was on Siquijor has been lost, and whatever the
identity of the wild pigs on Sibuyan, Masbate, Bohol and many other smaller,
or more isolated, islands, these populations are seriously threatened or
likely to become so in the near future. The recently recognized Visayan warty
pig is already extinct on two islands (Cebu and Guimaras) and endangered on
the only other islands (Negros and Panay) on which it is known to occur. As a
result, this species is now rated as one of the most endangered of all wild
suids. In a very real sense, this situation also reflects a
much wider, and in many ways quite astonishing, upheaval in our understanding
and appreciation of the genetic diversity and conservation status of the
suiformes which has occurred over the past twenty years or so. The key events
include the recognition, in 1969, of an isolated population of pygmy hippo
from the Niger Delta, as a separate subspecies (Hexaprotodon liberiensis heslopi). The present status of this
animal is not known, though it is rumored to survive (Corbett, 1969; Grubb,
this vol. a; Eltringham, this vol.). In 1971, the (somewhat dramatized)
'reappearance' of the pigmy hog (S. salvanius) was announced by tea planters
in N. W. Assam, following the burning of grasslands in one of only two small
areas still known to support remnant populations of this critically
endangered species. The continuing tenuous existence of this species,
arguably one of the most important indicator species for the enhanced
management of the crucially important tall grasslands, and certainly one of
the world's potentially most valuable genetic resources, is still the cas celebre of the Pigs and Peccaries Group, but by no means its only
concern. One of the most amazing large mammal discoveries of this century,
that of the giant peccary (Catagonus wagneri), has also emerged as one
of this Group's major preoccupations (Taber, this vol.). C. wagneri was
originally described in the 1930's from late Pleistocene material, and its
survival was unknown until some fresh skulls were collected from local
hunters during mammal inventory project in the Chaco of Paraguay in 1972
(Wetzel et al., 1975). In the process of unraveling the genus Sus, Groves (1981) also unearthed a
'mystery pig' (S. bucculentus),
which is still known from only two skulls collected in Cochin China (southern
Vietnam) before the turn of the century, and described a new subspecies of
warty pig (S. v. blouchi) from
skulls recently collected from the tiny island of Bawean, off N. E. Java.
Despite its minuscule range, the Bawean warty is thought to be relatively
secure at present, though the animal's external appearance remains virtually
unknown. Thanks to the observations of Hoogerwerf (1970) in Udjong Kulon
National Park, and various earlier authors, much more information was
available on the closely related Javan warty pig (S. v. verrucosus). However, these animals inexplicably
disappeared from Udjong Kulon sometime during the 1970's and, in the absence
of contemporary reports of their occurrence elsewhere, they were feared
extinct in the wild by the end of the decade (J. MacKinnon, pers. comm.).
Fortunately, this proved not to be the case, though the implementation of
recommendations arising from an island-wide status survey conducted the
following year at the Group's behest, have proved problematic (Blouch et al., 1983; Blouch, this vol.). A rather similar situation obtained at about this
time with another, equally extraordinary suid, the 'golden' or 'hairy'
babirusa (B. b. babyrussa), from
Buru and the Sula Islands. However, it was not until the late 1980's, after
an interval of about thirty years, that the first confirmed reports of the
continuing existence of these animals were finally obtained (Macdonald, this
vol.). As in this instance, relevant field data may be very difficult to
acquire simply because of the remoteness or inaccessibility of the areas.
Buru, for example, being a penal colony until quite recently, was closed to
visitors. In countries like Indonesia and the Philippines, the sheer
logistics of trying to obtain recent population status data, let alone
research specimens, over all or most of a species' known or presumed range,
is at best daunting and at worst either effectively impossible or cost
prohibitive. Despite a high probability of new taxa awaiting discovery, or
becoming extinct before discovery, many islands have never been surveyed or
even visited by biologists. Permits for obtaining specimens for captive
breeding programs or scientific study, and/or accessing those specimens for
examination by specialists, is also becoming increasingly difficult. This is
particularly true in the case of wild pigs, where concern (sometimes
amounting to paranoia) in the pork industry about the possibility of disease
transmission, has resulted in total bans or excessively stringent veterinary
regulations being imposed on the movement of wild pig specimens across (in
some cases even within) national boundaries. Nonetheless, this work continues as opportunities
are presented or created, and a good deal of progress has been made in some
areas. Even so, the exercise is often difficult, frequently more frustrating
than rewarding, and almost always salutary. Even as initial priorities are identified
and (where practical) addressed, old problems are seldom vanquished and new
questions, problems and priorities multiply. The recent upheaval in our
understanding of these animals is far more a reflection of our ignorance than
of our knowledge. A great deal of basic data on the distribution, population
status, ecology and behavior of most species of wild suiformes are still
required, and these needs must be tackled if we hope to develop the most
appropriate management strategies for these species. In the broadest terms, these are the reasons and the
justification for this Action Plan - or, more precisely, these 'action
plans', since the modest number of extant species (currently 18, excluding
the enigmatic Sus bucculentus)
within the purview of the Pigs and Peccaries and the Hippo Specialist Groups,
has enabled us to produce an 'action plan' for each species, and even a few
related topics. The format adopted (which has been unashamedly lifted from
the now, sadly defunct, Red Data Books) has also allowed us the luxury of
including summaries of much of what is already known about the taxonomy,
distribution, ecology and behavior of each species. This was done both as a
deliberate attempt to pull these data together, and as a means of identifying
some of the starkest gaps in our knowledge; thereby providing perspectives
and justifications for most of the emergent recommendations. By the same
token, we have endeavored to produce priority recommendations for useful
future research and conservation management of each of these species and
topics, both as an exercise for people with specialist interests and as the
source of reference for the various, highest priority recommendations which
are brought together in the regional reviews at the end of each section. William L. R. Oliver References Anon 1993. First
Cypriots feasted on hippos. New Scientist 137 (1855): 18. Blouch, R. A.
1993. The Javan warty pig, Sus
verrucosus. pp 129-136. In: Pigs, Peccaries and Hippos Status Survey and
Action Plan. Ed. by W.L.R. Oliver. IUCN/SSC Pigs and Peccaries Specialist
Group and IUCN/SSC Hippos Specialist Group, Gland, Switzerland 202 pp. Blouch, R. A.,
Banjar Y. L., Heri D. S., and Sumaryoto A. 1983. The Javan Warty Pig:
Distribution, Status and Prospects for the Future. (Unpubl.) rep. to World
Wildlife Fund, Bogor: 32pp. Caldecott, J.
and Nyaoi, A. 1985. Sarawak's wildlife: a resource to be taken seriously.
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387-394. Cox, C. R.
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and Grubb, P. 1993. The Eurasian suids, Sus
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379-381. |
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Suborder Suiformes |