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Babirusa is a mammal belongs to Suidae family. This mammal belongs to Babyrousa genus is known endemic to Indonesia. Recently there are 3 species of Babyrousa, one species is Babyrousa babyrussa, listed as ‘Vulnerable’ on the IUCN Red List of Threatened Species. Babyrousa occurs in Indonesia on Sulawesi island, Togian, Sula islands, and Taliabu, Mangole and Buru islands in the Molucca regions. The Moluccan Babirusa is now restricted to upland forests and mountainous terrain. Then this study aims to assess the suitability of Buru island as habitat for Moluccan Babirusa. The suitability analysis was based on GIS analysis using 4 determinant environmental variables required by B. babyrussa species including NDVI, barren soil, elevation, and river network. The particular location was a Batabual landscape sizing 292.60 km2 located in the east parts of Buru island. Based on NDVI, less vegetation covers were observed in north and east parts of Batabual. In contrast, NDVI values were higher in the central, west, and south indicating that half of the landscape was covered by intact primary forest. Batabual has a hilly landscape surrounded by coastal areas with hilly areas were observed in the south and west. There were 2 river streams in the east parts. The analysis has divided the landscape into several parts based on the habitat suitability levels. About one third of the landscape located in north was considered less and not suitable for Babirusa. Some areas in west were also considered moderate to be inhabited by Babirusa considering a presence of hilly landscape that may limit the vertical distribution of Babirusa. Most suitable habitats were estimated in central parts of the landscape spanning to the south. South parts of the landscape were characterized by high NDVI values and forest covers then these areas were considered as suitable habitats for Babirusa. The size of this suitable habitat was estimated around 188.62 km2 or more than half of the size (64.46%) of Batabual landscape.

Besides chemical testing, thermographic imaging is a possible method to determine pregnancy in some animals. Hilsberg (2001) defined the unilateral warming at the end of a pregnancy, caused by the metabolizing fetus and the uterus near the outer skin, as the pregnancy field. Its appearance was observed in various species at the end of the gestation period. No studies were yet carried out to investigate the changing of thermal patterns during pregnancy. This study monitored the thermographic changes of one pregnant babirusa (Babyrousa babyrussa) sow and one babirusa male by taking thermal images once a week from the estimated 3rd pregnancy week until parturition in the 23rd pregnancy week. Images were searched manually for heat areas correlated to pregnancy as well as analysed automatically for median and maximum temperatures of the animal's side. Additionally, the locations of all pixels, which were not more than 2 K below the maximum temperature, were evaluated. In the female, there was a positive correlation between maximum temperatures of left and right side to pregnancy weeks (R = 0.61, R = 0.66, respectively; p 0.05). The female's median temperatures and all temperatures of the male were not correlated to pregnancy weeks. Differences between median and maximum temperatures were significantly different during the 2nd, and 3rd trimester in the female, but not in the male. Temperature differences between 1st and 2nd trimester were not significant in both animals. The location of the warmest areas in the female shifted from thorax and flank to be mainly localised on the teats. In the male, the warmest areas remain localised on thorax and flank. No distinct pregnancy field was observed, but the warming of the teats could be seen in the images and the evaluated data. The teats are less insulated in most animals. Contraindications for thermal imaging like insulation could therefore become less important, allowing thermal pregnancy diagnosis for a larger range of animals than before. Based on these findings we suggest that the warming of the teats could be used for thermal pregnancy diagnosis when a pregnancy field is not observable.

The wear on the occlusal surfaces of male babirusa cheek teeth was evaluated in 53 skulls of Babyrousa babyrussa from Buru and the Sula Islands and 87 skulls of B. celebensis from Sulawesi, Indonesia. Based on the comparative lengths of their continually growing maxillary canine teeth, the skulls were divided into five ‘age categories’ (A–E). Numerical and symbolic codes representing tooth wear were applied to each pillar (cusp region) of the mandibular and maxillary permanent third and fourth premolar teeth, and the first, second and third permanent molar teeth. There was no significant difference between the tooth wear patters of skulls in groups A and B, or in groups C and D, and so these were amalgamated. There was close correspondence in wear patterns between each side of the mouth in both species and in each age group. The wear patterns of the mandibular and maxillary teeth, although not identical, were very similar, as were the wear patterns of both species. In group A + B for both species tooth wear was relatively slight, with the M1 teeth experiencing most relative wear. There was almost no wear of the M3 teeth. In group C + D substantial wear of upper and lower M1 was evident. In group E more widespread wear of the cheek teeth was seen, with increased severity of M1 tooth wear, yet there was comparatively much less M2 and M3 tooth wear. The pattern of cheek tooth wear of the Babyrousa spp. was different from that shown by Sus scrofa. Differences in diet selection and processing were highlighted as potential contributing factors. The pattern of cheek tooth wear in male babirusa was not adequate for use to monitor their age.

The objective of this research is to evaluate the ecosystem functions through vegetation and wildlife indicators. Methods used are vegetation analysis and direct indirect method to count wildlife . Results show that the dominant type of land coverage in Gunung Ambang Nature Reserve is open secondary forest, where shrubs, rattan, and epiphytes dominated. This might lead to vulnerability of the site toward disturbance. Furthermore, it was indicated that this area still contains local wildlife species such as Babyrousa babyrussa celebensis. Eventhough land degradation has become a significant issue, the status of Gunung Ambang as nature reserve has limited restoration attempts both vegetatively and mechanically.

The first description of Babirusa on the [Indonesian] island of Buru may be found in a letter written in 1584 by Fr. Bernardino Ferrari describing the wildlife on Buru. In his own words: ‘È l’isola del Burro molto fertile de victovaglie di queste parti, habundante de molti animali sylvestri, come de porci et altri animali di queste parti. Fra quali vi sono uni semeglianti al porco ma bianchi. E li due denti grandi, con i quali i porci combetteno, questi animali le tengono diretti di modo che furan oil musso del detto animali, e uscindo sopra appariscono come due chiodi grandi.’ [amongst which [animals] there are some resembling pigs, but white. The two tusks which pigs use to fight with, these animals have straight, in such a way as to pierce the snout of the said animal, sticking out on top like two great nails] (Jacobs 1980).

This study utilized conventional and immunohistochemical methods, to describe the morphology and distribution of glucagon and insulin cells in the pancreas of adult male babirusa (Babyrousa babyrussa). The results of research showed that the endocrine portion (Langerhans islet) spread evenly on the acinar portion of pancreas. Observation using immunohistochemical method showed that glucagon cells were distributed on the perifer, whereas insulin cells in the center of the Langerhans islet of pancreas. In general, the number of insulin cells was higher than glucagon cells. It is interesting to note, in the pancreas babirusa also found that neonatal elements similar to the Langerhans islet, but have larger sizes (ranging between 200 -700 mm). The picture is similar to the large Langerhans islet was reported in ruminant. These cells give a negative reaction to insulin and glucagon antisera.

Mating of a babirusa (Babyrousa babyrussa) boar and a domestic sow (Sus scrofa) resulted in the birth of 5 live domestic pig-babirusa hybrid piglets. Chromosome analysis of one of the surviving males confirmed that they were domestic pig-babirusa hybrids by revealing the presence of a complete haploid set of 19 porcine chromosomes as well as a complete haploid set of 19 babirusa chromosomes in the karyotype. None of the surviving piglets, two males and one female, had shown signs of sexual maturity at age 27 months. Histological examination of gonadal biopsies from the 2 males revealed that both were azoospermatic. Immunostaining revealed SCP3-positive axial elements in the nuclei of primary spermatocytes, indicating that they were progressing through leptotene and zygotene of meiotic prophase. However, the presence of multiple short stretches of axial elements in pachytene nuclei indicated that this phase was blocked, probably due to aberrant chromosome pairing. Histological examination of the ovaries revealed follicular structures, but oocytes within them were generally degenerated. We conclude that both male and female pig-babirusa hybrids were infertile, most likely due to germ cell death resulting from abnormalities of chromosome pairing during meiotic prophase.

The objectives of this study were to analyse faecal steroid metabolites in African and South East Asian pig species kept in European zoos. Species studied were the warthog (Phacochoerus africanus), the red river hog (Potamochoerus porcus) and the babirusa (Babyrousa babyrussa). Faecal samples were collected 1-3 times per week from non-pregnant and pregnant captive female warthogs (n = 9), red river hogs (n = 7) and babirusas (n = 5). Enzyme-immunoassays for faecal progesterone, androgen, and oestrogen metabolites, were tested for their ability to determine follicular and luteal phases. In all three species, oestrous cycles could be monitored with 20alpha-OH- and 20-oxo-pregnane assays. In contrast, oestrogens and androgens were not useful in characterising follicular activity during the oestrous cycle in any species. Faecal 20alpha-OH- and 20-oxo-pregnane values were significantly correlated. Faecal pregnane concentrations revealed species-specific differences. Luteal phase values of 20alpha-OH-pregnanes were considerably higher than 20-oxo-pregnanes; 20alpha-OH-pregnanes were in the range of 3-10 microg/g in warthogs and red river hogs, whereas concentrations were 30-200 microg/g faeces in the babirusa. Regular oestrus cycles had a length of about 35 days in all three species studied. Results indicated a seasonal influence on the occurrence of reproductive cycles in the warthog with anoestrous periods in the European summer. The red river hog was found to be a seasonal and poly oestrous breeder; oestrus cycles started by January and continued until summer. In contrast, the babirusa showed non-seasonal ovarian cyclicity. In pregnant red river hogs, progesterone metabolites were comparable to luteal phase values of the oestrous cycle during the first 3 months of gestation, but did further increase during the last month of pregnancy. Oestrogens and 17-oxo-androstanes were significantly elevated during the second half of gestation. In summary, the reproductive biology of three exotic pig species was studied using non-invasive faecal steroid analysis and these methods were used for comparative investigations of oestrous cycles, pregnancy and seasonality.

Five novel herpesviruses were identified in suid species from Africa (common warthog, Phacochoerus africanus) and South-East Asia (bearded pig, Sus barbatus; babirusa, Babyrousa babyrussa) by detection and analysis of their DNA polymerase genes. Three of the novel species, P. africanus cytomegalovirus 1, P. africanus lymphotropic herpesvirus 1 (PafrLHV-1) and S. barbatus lymphotropic herpesvirus 1 (SbarLHV-1), were closely related to known beta- (porcine cytomegalovirus) and gammaherpesviruses [porcine lymphotropic herpesvirus (PLHV) 1 and 3] of domestic pigs. In contrast, two novel species, S. barbatus rhadinovirus 1 (SbarRHV-1) and Babyrousa babyrussa rhadinovirus 1 (BbabRHV-1), were more closely related to a ruminant gammaherpesvirus, bovine herpesvirus 4 (BoHV-4), than to the porcine gammaherpesviruses PLHV-1, -2, -3, PafrLHV-1 and SbarLHV-1. SbarRHV-1, BbabRHV-1 and BoHV-4 were therefore tentatively assigned to a novel genogroup of artiodactyl gammaherpesviruses. This latter genogroup may also contain an as yet undiscovered gammaherpesvirus of domestic pigs, thereby adding a concern to their use in xenotransplantation.

3Wildlife Trust, Palisades, New York The nursing behavior of eight babirusa ( Babyrousa babyrussa) infants was studied. Four were from single births and four were from twin births. The age at weaning, the time of day and number of nursing bouts per day, the mean duration of nursing bouts, and whether the offspring or the dam ended nursing bouts were all examined. It was found that although twins are weaned earlier than single offspring, there were no other statistically significant differences in nursing behavior of single and twin offspring. The ontogeny of nursing behavior in this species is described and some comparisons are made between the nursing behavior of babirusa and nursing in the domestic pig (Sus scrofa) and selected suids. Babirusa dams take longer to wean their offspring, allow them to nurse longer, and end nursing bouts less often than domestic pigs. The differences in behavior between babirusa and domestic pig nursing behavior may be related to differences in the number of offspring produced by the two species and the amount of parental investment in each offspring. Zoo Biol 19:253‐262, 2000. © 2000 Wiley-Liss, Inc.

The babirusa ( Babyrousa babyrussa ), an endangered suid endemic to Sulawesi, Indonesia, has scarcely been studied in the wild. Sixty hours of observation on social organization of babirusa and patterns of visitation to a natural salt lick were made during 32 months in 1989–1994. Babirusa groups observed at the lick were 1–13 individuals ( n = 393 groups), and solitary adult males or matriarchal groups were the most frequently sighted group types. A daily pattern of visits to the lick was discernible with the highest number of groups at the lick between 1700–1800 h. Mean duration of visit was greatest (17.4 min) between 1700–1800 h. Use of the lick differed markedly among mammalian species; 98.0% of all activity was of babirusa compared with

We compared 1,047 base pairs (bp) of the mitochondrial cytochrome b gene from the three species of extant peccaries—the collared peccary ( Pecari tajacu ), the white-lipped peccary ( Tayassu pecari ), and the Chacoan peccary ( Catagonus wagneri ); three suids—domestic pig ( Sus scrofa ), warthog ( Phacochoerus aethiopicus ), and babirusa ( Babyrousa babyrussa )—were used as outgroups. Phylogenetic analyses using parsimony and maximum likelihood resulted in trees that placed the Chacoan peccary and the white-lipped peccary in a clade separate from the collared peccary. This relationship remains tentative, however, as tree topologies supporting alternate hypotheses were not significantly worse than the maximum likelihood tree. Estimated times since divergence based on cytochrome b suggest that Tayassu and Catagonus diverged in the late Pliocene, perhaps concommitant with the invasion of South America by tayassuids. The divergence of the Pecari lineage from that of the other two species was estimated to be at 3.4–7 4 × 106 years ago, supporting the hypothesis that these two clades diverged in North America before either clade colonized South America. Our results support the classification of extant species of peccaries into three genera.

The locations of the genes encoding 18S, 5.8S and 28S rRNA and 5S rRNA were studied in two relatives of the domestic pig, the babirusa (Babyrousa babyrussa) and the white-lipped peccary (Tayassu pecari). In the babirusa, the 18S, 5.8S and 28S rDNA is located on chromosomes 6, 8 and 10. The genes on chromosomes 8 and 10 are actively transcribed, in contrast to those on chromosomes 6. In the white-lipped peccary, this rDNA was found to be located on chromosomes 4 and 8. The genes on both of these pairs of chromosomes are actively transcribed. The 5S rDNA was physically mapped to chromosome 16 in the babirusa, and to chromosome 11 in the white-lipped peccary. These data are compared to similar data obtained for the domestic pig, and confirm previously recognized chromosome homologies.

A unique form of behaviour,‘ploughing behaviour’, was studied in experiments carried out on 13 babirusa, three adult males, two sub-adult males, five adult females and three sub-adult females. Ploughing behaviour was observed when individual animals were introduced singly into empty sand-filled enclosures at Antwerp Zoo. The animal put its snout into the sand to such a depth that the sand was just in front of its eyes, whereupon it knelt and slid forward on to its chest. The head and chest of the animal were thereby pushed forward through the sand and canted left and right alternately. Ploughing behaviour was almost exclusively performed by adult males, the periods of longest duration being seen either in the enclosure of another male or in a freshly cleaned enclosure. The copious amounts of saliva which were produced as foam at the sides of the mouth prior to ploughing had disappeared by the end of this activity. This supports the idea that ploughing by the babirusa has a scent-marking function. The adult female did not show ploughing behaviour.

Homology among three pairs of domestic pig (Sus scrofa) and five pairs of babirusa (Babyrousa babyrussa) autosomes has been demonstrated with the use of porcine painting probes. With the results of this study, in addition to data obtained earlier through the application of banding techniques, correspondence between all individual chromosomes of these two distantly related pigs has been identified.

Summary A description is given of the anatomy of the extrinsic and intrinsic muscles of the forelimb of the babirusa (Babyrousa babyrussa, L. 1758). Three adult animals, two males and a female were dissected and the results compared with the previously published information. Significant differences were found between the accounts, and these were analysed within the contexts of material availability and advances in anatomical nomenclature. Comparisons made with published descriptions of the pig (Sus scrofa) showed that the muscular anatomies of the two species are very similar. Four structures are present in the babirusa but not in the pig; the M. pronator teres is completely tendinous, a tendon branch from the Caput craniale m. extensor digitorum lateralis anastomoses with the tendon of the Caput intermedium m. extensor digitorum communis to the fourth digit, there is an additional small deep portion of the M. supraspinatus and a bundle of fibres from the M. pectoralis profundus inserts on the Intersectio clavicularis. Four structures present in the pig but not the babirusa are an additional insertion from the M. cleido-occipitalis into the raphe of the neck, and extra medial insertion of the M. infraspinatus, the accessory tendinous origin of the M. flexor digitorum profundus and the ulnar head of the M. flexor carpi ulnaris.

2. Moluccan Babirusa Babyrousa babyrussa French: Babiroussa des Moluques / German: Molukken-Hirscheber / Spanish: Babirusa de Molucas Taxonomy. Sus babyrussa Linnaeus, 1758, “Borneo” (= Buru Island, Indonesia). This species is monotypic. Distribution. Moluccas Archipelago, in Sula ls (Mangole & Taliabu) and Buru. Descriptive notes. Head—body 85-110 cm, tail 20-32 cm, shoulder height 65-80 cm; weight 43-100 kg. B. babyrussa is a relatively small species, with long, thick body hair and well-developed tail tuft. The upper canines of males are short and slender and cross the lower caninesin lateral view. The upper canines tend to diverge or be subparallel, but they may be weakly convergent. Based on tooth measurements, B. babyrussa is similar to B. bolabatuensis, a presumably extinct form described from subfossil remains retrieved from various sites in the south-western peninsula of Sulawesi. Habitat. Buru’s natural vegetation is largely tropical lowland evergreen and semi-evergreen rainforest, with tropical montane rainforest occurring above 800 m above sea level; the only known exception to this pattern is a complex patchwork of monsoon forest, gallery forest, and savanna in the north and north-east section of the island, the result of repeated anthropogenic burnings. No surveys have been done on the habitat use of babirusas on Buru Island, but the local Rana people report that babirusas are most often found in rocky habitat in hilly areas and mountains. Food and Feeding. [Local people on Buru report that babirusas primarily feed on leaves, roots, and fruits in the forest, but never enter people’s gardens to feed on crops, unlike the other pig species on Buru, which causes considerable damage to crops. The species is also said to feed along the shoreline when the tide is out. Breeding. Nothing is known about the breeding behavior ofthis species, but it is likely to be similar to other Babyrousa spp. Activity patterns. On Buru, B. babyrussa is mostly seen during the morning and late afternoons, but rarely around midday. Movements, Home ma@ nnd Social organintion. On Buru, babirusas are reported to be mostlv solitary or may occasionally be encountered in small groups. When in a group they regularlv emit a long and high pitched sound described as “suirii....suuuuuiiiriiii. " Status and Conservation. CITES Appendix I. Classified as Vulnerable on The IUCN Red List. The speciesis reported to be extinct on Sanana Island (formerly Xulla Besi). Some workers seem to believe babirusas were introduced to these islands, though if this is true these same workers provide no indication of their likely place of origin. Unfortunately, the systematic relationships of babirusas from adjacent eastern and south-eastern parts of Sulawesi remain unknown, so it is also not possible to assess their presumed or potential close affinities to B. babyrussa. During extensive survey efforts on Buru in 1995, no direct evidence of babirusas was found, although a pair of pig mandibles found inland from Fogi, in logged forest at an elevation of 670 m, indicated that the species had been recently hunted. Village interviews in 1997 about the species’ presence suggested that on Buru its range had become fragmented by the 1990s,although locally the animals were still relatively common. The species reportedly was not uncommon on the slopes of Gunung Kepala Mada, the highest mountain on Buru. No surveys have been conducted since, however, and the present status is unclear. The people of Buru differentiate babirusas from other suid species, though it is presently unclear whether any other suids occurring on Buru are of S. celebensis or feral S. scrofa origin, nor whether any such populations (assuming they exist) are naturally occurring or introduced forms.With half the people of Buru being Christian and therefore willing to eat pork, hunting pressure on pigs is likely to be high. The Rana people of Buru frequently hunt babirusas with dogs and snares. Although the northern portions of Buru island have been degraded by repeated burning and the coastal lowlands have been cleared, the remaining forest forms two large, contiguous blocks. Bibliography. Deninger (1909), Groves (1980), Macdonald et al. (2008), Meijaard & Groves (2002a, 2002b), Sody (1949), Tomie & Persulessy (1996), Verbelen (2003)., Published as part of Don E. Wilson & Russell A. Mittermeier, 2011, Suidae, pp. 248-291 in Handbook of the Mammals of the World – Volume 2 Hoofed Mammals, Barcelona :Lynx Edicions on page 276, DOI: 10.5281/zenodo.5721014

Among the artiodactyla, the suids are a group whose digestive physiology has hardly been investigated. The apparent digestibilities (aD) of macronutrients were measured in captive specimens of warthog (Phacochoerus africanus), red river hog (Potamochoerus porcus), and Visayan warty pigs (Sus cebifrons), and compared with those reported for babirusa (Babyrousa babyrussa) from the same facility on a similar diet. The animals were fed mixed diets of pelleted feed, grains, fruits, and vegetables; dietary neutral detergent fiber (NDF) ranged from 17 to 26% dry matter. aD of organic matter and protein ranged from 72 to 89 and 70 to 82%, respectively. Although red river hogs and warty pigs achieved aD of NDF of 41-54%, this value was higher both in warthogs (63-66%) and babirusa (61-63%). aD of acid detergent fiber was comparatively low in red river hogs (4%), warty pigs (22%), and babirusa (13-25%) but high in warthog (59-62%). Comparison with additional literature data (including peccaries) indicates that in spite of differences in digestive anatomy, suids and peccaries are similar, and resemble other herbivores in fundamental characteristics, such as the negative influence of fiber on overall digestibility, or the positive influence of dietary protein on protein digestion. Although the existing data are equivocal as to a superior fiber digestion in peccaries as compared with other wild suids, the results suggest that warthogs are more efficient than other wild suids or peccaries in terms of fiber digestion. Zoo Biol 27:305-319, 2008. (c) 2008 Wiley-Liss, Inc.

The babirusa (Babyrousa babyrussa) is believed to be the most distinct pig genus in the world. For example, among a number of unique anatomical characteristics, it is the only mammal with vertically growing canine teeth. Endemic to Sulawesi, and found on a few neighbouring islands such as Buru, Mangole, Taliabu and the Togian islands, the babirusa has a very limited geographical distribution. The available evidence seems to indicate that this is because Sulawesi has long been isolated by water from mainland Asia; the strait between Sulawesi and Borneo was apparently never narrower than about 50 kilometres during Pleistocene times. The current hypothesis is that the Babyrousa developed along a separate evolutionary line since Oligocene times (Thenius, 1970). This concept is supported by analyses of chromosome banding patterns that indicate that the chromosomes of the babirusa differed from those of other wild pigs (see Bosma et al, 1991). However, more recent work using DNA probes have shown that there are closer similarities between the chromosomes of Sus and Babyrousa than previously thought (Thomsen et al, 1996). DNA studies are beginning to reveal detailed molecular information with regard to the nature of the relationships babirusa has with other extant pig species (Randi et al, 1995; Lowden et al, 2002). New genetic analyses can be expected to give a much better understanding of the origin of the babirusa.

Although very little is known about the diet of Babirusa in the wild, they have been successfully kept in captivity in zoos around the world for 200 years. Studies have shown that the anatomy of their digestive tract is quite different from that of the domestic pig and as a consequence their food digestion is also likely to be different. As part of a wider study of the digestion of the Babirusa, the diet fed to animals in 25 zoos worldwide (16 Europe, 7 USA, 2 Indonesia) were analysed for their nutritional content. The results of these analyses will be presented and discussed in the light of the findings of other recent experiments on the food selection, diet digestion and foraging behaviour of Babirusa.

Previous studies have indicated that the gross anatomical structure of the stomach of the babirusa (Babyrousa babyrussa) differs markedly from that of all other pigs. This light and scanning electron microscopic study revealed a previously unknown, microscopic structure characterised by a 'honeycomb' pattern at the luminal surface of the tunica mucosa. The walls of the 'honeycomb' were about 0.20-0.25 mm high and appeared almost entirely composed of various types of bacteria. Underneath the bacteria the walls were formed by thin tubes composed of non-glandular squamous epithelial-like cells, extending from the tops of the ridges between each glandular pit. There is as yet no evidence of a comparable structure in the stomach of any other pig, or to our knowledge any other forestomach-fermenting mammal.

This case report documents the application of transabdominal ultrasonography for detecting pregnancy and monitoring fetal development in an unanesthetized, unrestrained babirusa (Babyrousa babyrussa). A 4-yr-old multiparous female babirusa was trained to accept monitoring via transabdominal ultrasonography on a weekly basis postcoitus. Uterine changes associated with pregnancy were first detected at 30 days gestation. Three fetuses were first visualized on day 38, and two of the three fetuses were detectable until term. One fetus failed to develop and appeared to be resorbed between days 80 and 94 of the 161-day pregnancy. The growth of the remaining two fetuses was monitored via cranial measurements taken during the weekly scans throughout the pregnancy. By monitoring a subsequent pregnancy via ultrasound in the same female it was possible to confirm her tendency towards partial resorption, with earliest detection of uterine changes on day 32 and apparent resorption of one of three fetuses at approximately the midpoint of gestation. Two rectal scans of a different female under anesthesia at 28 and 50 days gestation showed stages of development comparable to those visualized transabdominally. However, the transabdominal scans produced better images of the reproductive tract, perhaps because of the close proximity of the pregnant uterus to the abdominal wall.

Stomachs from six adult and one 12-month-old babirusa (Babyrousa babyrussa) were collected from zoological gardens. The babirusa stomach was larger than that of the domestic pig (Sus scrofa), and possessed a large diverticulum ventriculi. Its gastric glands were confined to a small, easily identifiable unit at the end of the corpus ventriculi, and the connections between the different stomach parts were wide and unrestricted, with the exception of the well-defined connection between the diverticulum ventriculi and the fundus ventriculi. Microscopically, the structure of the cardiac, gastric and pyloric glands was similar to that of Sus scrofa. However, the mucusproducing cardiac glands of babirusa occupied a larger area within the stomach (> 70% versus 33%). The pH in the lumen of the cardiac gland area lay between 5.3 and 6.4 and micro-organisms were found here. It was hypothesised that the babirusa is a nonruminant foregut-fermenting frugivore/concentrate selector.

This paper reviews the available information on stomach anatomy, digestion, foraging behaviour and diet of wild and captive babirusa. Based on this information, suggestions for changes in the diet of captive babirusa are formulated, which will then need to be assessed.

Summary The distribution and relative frequency of endocrine cells in the gastrointestinal tract of the babirusa were studied immunohistochemically using the avidin-biotin-peroxidase complex method. Thirteen types of gut endocrine cells were detected; they were immunoreactive for chromogranin, serotonin, somatostatin, gastrin, bovine pancreatic polypeptide (BPP), glucagon, secretin, cholecystokinin (CCK), methionine–enkephalin–Arg6–Gly7–Leu8 (MENK8), motilin, gastric inhibitory polypeptide (GIP) and peptide tyrosine tyrosine (PYY). Cells that were immunoreactive for chromogranin, serotonin, somatostatin and glucagon were found in all portions of the gastrointestinal tract. MENK8-immunoreactive cells were observed in the stomach and small intestine. Gastrin-immunoreactive cells were detected in the pyloric region and duodenum. PYY-immunoreactive cells were found in the small and large intestine. Cells immunoreactive for motilin, CCK, GIP, and secretin were observed in the proximal small intestine and those immunoreactive for neurotensin were found only in the ileum. Although the distribution pattern of endocrine cells in the gastrointestinal tract of babirusa was similar to those reported for pig, restricted distribution of several endocrine cells, gastrin, BPP, MENK8, motilin, CCK, GIP, secretin and neurotensin and wider distribution of glucagon and PYY were observed in the babirusa. The unexpected presence of MENK8 in all glandular regions of the stomach and PYY in the small intestine was also noted. The distribution of gut endocrine cells might be related to the regulatory characteristics of the babirusa digestive tract.

Interest in the nutrition of wild and captive wild animals has grown exponentially during the last few years. In the past, the amount of research carried out on domesticated animals, mainly geared towards improving economic efficiency of production of meat and dairy products, vastly outweighed research performed on wild animals. During the last two decades heightened public awareness of the need for nature conservation and for respect for animal welfare have brought new reasons for, and meaning to, further research in the fields of both domestic and wild animal nutrition. As natural habitat becomes more and more fragmented and as wild animals are more and more confined to protected wildlife areas designated by man, a thorough knowledge of the feeding ecology of the wild animals living in these areas becomes essential for the successful conservation of these species. Furthermore, assisting nature conservation now constitutes one of the main goals of modem zoos

A unique form of behaviour, 'ploughing behaviour', was studied in experiments carried out on 13 babirusa, three adult males, two sub-adult males, five adult females and three sub-adult females. Ploughingbehaviour was observed when individual animals were introduced singly into empty sand-filled enclosures at Antwerp Zoo. The animal put its snout into the sand to such a depth that the sand was just in front of its eyes, whereupon it knelt forward onto its chest. The head and chest of the animal were thereby pushed forward through the sand and canted left and right alternatively. Ploughing behaviour was almost exclusively performed by adult males, the periods of longest duration being seen either in the enclosure of another male or in a freshly cleaned enclosure. The copious amounts of saliva which were produced as foam at the sides of the mouth proir to ploughing had disappeared by the end of this activity. This supports the idea that ploughing by the babirusa has a scent-marking function. The adult female did not show ploughing behaviour.

The chromosomes of the babirusa, a species considered to have diverged from an ancestor of the pig during the Miocene epoch, about 12–26 million years ago, were studied to determine the sites of recent rearrangements during evolution of the domestic pig. It is shown that there is a pericentric inversion of the entire short arm on pig chromosome 1, compared to its counterpart in the babirusa (chromosome 15). We also present evidence suggesting that pig chromosome 3 was derived by a telomere-centromere fusion of two ancestral chromosomes homoeologous to babirusa chromosomes 12 and 17. Likewise, we conclude that pig chromosome 6 was most likely derived by a telomere-telomere fusion of ancestral chromosomes homoeologous to babirusa chromosomes 6 and 14. The detection of interstitial hybridization signals from presumptive subtelomeric repeats in the same chromosome region as the evolutionary fusion points on pig chromosomes 3 and 6 indicates that the fusion sites may still contain elements that are otherwise restricted to the telomere regions of pig chromosomes.

Studies of the anatomy, behaviour, physiology, and veterinary medicine of the babirusa have contributed to our understanding of the biology of the animal. The first part of this paper seeks to illustrate by means of examples how studies of the babirusa are currently being carried out. The second part addresses the topic of reporting the results of research studies. The information generated by research can often be translated into ideas and suggestions for the improvement of zoo practice with respect to enclosure design, nutrition, reproduction and veterinary care. However, it is more important that the next step is also addressed, namely the knowledgeable and interesting display of information to the general public.

The structures of the placenta and the cardiac foramen ovale of the babirusa (Babyrousa babyrussa) were studied by means of light and scanning electron microscopy, with material from eleven fetal and neonatal animals. The babirusa has a diffuse epitheliochorial placenta. The chorion of the term placenta is fusiform in shape, and most of its surface comprises rows of villi interrupted by round, oval or irregularly shaped aerolae. A network of fetal placental capillaries indents the epithelial layer covering the tops and sides of the interareolar villi. The round and oval areolae have slender, irregularly shaped villi. The irregular areolae have undulating surfaces without villi. The umbilical cord contains two arteries, one vein and the urachus. The foramen ovale, when viewed from the terminal part of the caudal vena cava has the appearance of a tunnel; a fold of tissue projects from the caudal edge of the foramen ovale into the lumen of the left atrium. This fold, the distal end of which is straight-edged, constitutes a large proportion of the tube, the remainder being formed by the atrial septum. Comparison of the anatomy of the placenta and heart with those of members of the Suidae and Hippopotamidae indicates that the babirusa has more characters in common with the pigs than with the hippos.

Babyrousa babyrussa (Linnaeus, 1758). Syst. Nat., 10th ed., 1:50. TYPE LOCALITY: "Borneo" (= Buru Isl, Indonesia). DISTRIBUTION: N and C Sulawesi, Lembeh Isl, Buru (N Molucca Isis), Sula Isis, Malengi Isl (Togean Isis). STATUS: CITES - Appendix I; U.S. ESA - Endangered; IUCN - Vulnerable. SYNONYMS: alfurus, beruensis, bolabatuensis, celebensis, frosti, quadricornua, togeanensis., Published as part of Peter Grubb, 1993, Order Artiodactyla, pp. 377-414 in Mammal Species of the World (2 nd Edition), Washington and London :Smithsonian Institution Press on page 377, DOI: 10.5281/zenodo.7359189

The babirusa is known only from Sulawesi (B. b. celebensis), some of the Togian Islands (B. b. togeanensis), the Sula Islands and Buru (B. b. babyrussa). Two extinct forms, one fossil and one recent (B. b. bolabatuensis), have been found in South Sulawesi. The species is therefore presumed to have been more widely distributed on Sulawesi in earlier times, but by the middle of the last century they were reported to occur only in the east and north-east parts of the island and to have disappeared from the whole of the south-western peninsula. Currently, babirusa are known only from the northern peninsula, central and south-eastern parts of the Sulawesi mainland, and from three of the larger Togian Islands Archipelago. Reports obtained in 1990 indicate that babirusa also survive on Buru and two of the Sula islands, Mangole and Taliabu, but that they may now be extinct on Sulabesi (formerly Sanana). However, there is no doubt but that babirusa are seriously threatened over most of their remaining range by deforestation and hunting pressure; the latter being particularly intense in parts of northern Sulawesi where there is commercial trade in the meat of these animals (Blouch, 1990; Budiarso et al., 1991). Much of the available information on the natural history and biology of this species is anecdotal or derived from the study of captive specimens. Distribution and status surveys in all parts of its range are required as a matter of high priority, with a view to the development of management plans for its enhanced future protection and the establishment of additional reserves in key areas, such as Buru, Mangole and the Togians. The possibility of relic populations of B. b. bolabatuensis surviving in remote locations in south Sulawesi should be investigated, and the taxonomic relationships of the central and south-eastern Sulawesi populations, which are unknown at present, need to be assessed. The first longer-term field study of the species' behaviour and ecology has been initiated recently in northern Sulawesi, and such studies should be continued and extended to other parts of the species' range in the near future. Particular emphasis should be placed on obtaining a proper understanding of its habitat preferences, population sizes and densities in different habitats, and the nature and extent of factors, such as hunting pressure, deforestation and agricultural encroachment, which are negatively influencing the distribution and numbers of surviving populations. Although there are large numbers of B. b. celebensis being maintained and bred in zoological collections at present, the captive population is extremely inbred. Priority should therefore be given to the acquisition of additional, wild-caught founders of this subspecies, and to the development of properly structured breeding programmes for the more threatened Togian subspecies, B. b. togeanensis, and, especially, the golden or hairy subspecies, B. b. babyrussa.

The babirusa is a remarkable pig, endemic on the Indonesian islands of Sulawesi, Buru and the smaller Sula and Togian islands. The single species of the genus is divisable into three living subspecies: Babyrousa babyrussa babyrussa (Sula Islands and Buru), B.b. togeanensis (Togian islands) and B.b. celebenesis (Sulawesi) (Groves, 1980), of which only the latter is currently represented in captivity. The species is listed in the IUCN Red Data Book as vulnerable and can be considered a marker animal for the disturbance of the primary rainforest. The Indonesian Department of Forest Protection and nature Conservation (Perlindungan Hutan dan Pelestarian Alam: PHPA) has given it the second most important priority after the Indonesian rhinos. This present paper reports the results of studies carried out on a large number of babirussa. Observations were made in Antwerp Zoo in Belgium and in the Zoos at Surabaya and Jakarta in Indonesia. These institutions represent 3 different ways in which the babirusa are currently kept in captivity. In Antwerp Zoo, each animal has its own enclosure; Surabaya Zoo keeps animals in large groups and Jakarta Zoo houses them in pairs. Each of these different housing techniques had its own implications on the behaviour shown by the animals and this allowed us to make suggestions for their future husbandry.

Studies were carried out at two ‘salt-licks’ in lowland tropical forest on North Sulawesi, Indonesia. During 60 days of observation 586 sightings of babirusa were made comprising 161 of adult males, 155 of adult females, 11 adults of unknown sex, 78 of subadult males, 53 of subadult females and 34 subadults of indeterminate sex; juveniles were observed 94 times, 19 males, 12 females and 63 of unknown sex. We saw 226 groups ranging in size from one to eight animals (median = 2). Almost half the sightings were of solitary animals, usually adult males. Bachelor groups of four or more babirusa were never seen. Adult females were rarely seen without company, often both juveniles and subadults being sighted together with them. There were never more than three adult females in a group. There were about twice as many family groups without adult males as there were with males. Agonistic behaviour between males was confined to ‘threat at a distance’, ‘nose in the air’, ‘head under jaw submission’ and ‘front half supported’ behaviours. There were fewer incidents of female-female agonistic behaviour, but in two, the dominant female chased her inferior off the ‘salt-lick’.

Babyrousa babyrussa (Linnaeus, 1758). Syst. Nat., 10th ed., 1:50. TYPE LOCALITY: "Borneo" (=Buru Isl., Indonesia). DISTRIBUTION: N. and C. Sulawesi; Buru (N. Molucca Isis.); Sula Isis.; Malengi Isl. (Togean Isis.). PROTECTED STATUS: CITES - Appendix I and U.S. ESA - Endangered. ISIS NUMBER: 5301419001001001001., Published as part of James H. Honacki, Kenneth E. Kinman & James W. Koeppl, 1982, Order Artiodactyla, pp. 315-343 in Mammal Species of the World (1 st Edition), Lawrence, Kansas, USA :Alien Press, Inc. & The Association of Systematics Collections on page 315, DOI: 10.5281/zenodo.7352976