ORYX VOL 29 NO 2 APRIL 1995 The saola or spindlehorn bovid Pseudoryx nghetinhensis in Laos George B. Schaller and Alan Rabinowitz In 1992 the discovery of a new bovid, Pseudoryx nghetinhensis, in Vietnam led to speculation that the species also occurred in adjacent parts of Laos. This paper describes a survey in January 1994, which confirmed the presence of P. ngethinhensis in Laos, although in low densities and with a patchy distribution. The paper also presents new information that helps clarify the phylogenetic position of the species. The low numbers and restricted range ofP. ngethinhensis mean that it must be regarded as Endangered. While some admirable moves have been made to protect the new bovid and its habitat, more needs to be done and the authors recommend further conservation action. Introduction area). Dung et al. (1994) refer to Pseudoryx as the Vu Quang ox, but, given the total range of In May 1992 Do Tuoc and John MacKinnon the animal and its evolutionary affinities (see found three sets of horns of a previously un- below), we prefer to call it by the descriptive described species of bovid in the Vu Quang local name 'saola'. Nature Reserve of west-central Vietnam The village of Nakadok, where saola horns (Stone, 1992). The discovery at the end of the were found, lies at the end of the Nakai-Nam twentieth century of a large new mammal in a Theun National Biodiversity Conservation region that had been visited repeatedly by sci- Area (NNTNBCA), which at 3500 sq km is the entific and other expeditions (Delacour and largest of 17 protected areas established by Jabouille, 1931; Legendre, 1936) aroused in- Laos in October 1993. Laos plans a major hy- tense interest. Four subsequent Vietnamese droelectric project on the Nam Theun, a river surveys produced the remains of over 20 par- whose primary watershed is the Conservation tial specimens of the bovid, which has been Area. The dam will inundate some of the low- given the scientific name Pseudoryx nghetinhen- lands in the conservation area. During January sis (Dung et al., 1993). One local name for the 1994 we collaborated with the Department of animal is saola, spindlehorn, because its long Forestry, Lao People's Democratic Republic, in tapered horns resemble a weaver's spindle a survey of the status of large mammals in the (Dung et al., 1994). Because all Vietnamese dis- region. During this survey we repeatedly found tribution records of saola were from the evidence of saola. A survey of this species out- forests of the Annamite Mountain range along side the conservation area is planned for the the Vietnam-Laos border, Dung et al. (1993) near future. Here we present preliminary data assumed that the species could also occur in that confirm the presence of saola in Laos and Laos. The first evidence of saola in Laos was indicate that a breeding population with a found by Robert Dobias who in early 1993 saw fairly extensive distribution exists. a set of horns at the village of Nakadok near the Vietnam border (Salter, 1993). The local people there knew the animal as saola or yang Study methods (not to be confused with yeang, the serow Naemorhedus sumatraensis, which is in size We interviewed villagers and other local peo- similar to the saola and also occurs in that ple about saola and walked about 415 km to ©1995FFPS 107 Downloaded from https://www.cambridge.org/core. IP address: 170.106.35.93, on 26 Sep 2021 at 17:33:16, subject to the Cambridge Core terms of use, available at https://www.cambridge.org/core/terms. https://doi.org/10.1017/S0030605300020974 G. B. SCHALLER AND A. RABINOWITZ Two Hmong tribesmen at the village of Nape with the horns of a female saola (George B. Schaller). assess the relative abundance and distribution montane evergreen broad-leaved forest at of large mammals in the Conservation Area. 200-2000 m a.s.l. (Dung et ah, 1993). The Local people living in or near the forest hunt Laotian side of the Annamites has terrain and and trap wildlife extensively, and this makes vegetation similar to that on the Vietnamese them usually reliable informants about the side, and the saola is probably found through- status of species within their area. The saola is out that part as well; however, our work has encountered so infrequently and has such a so far confirmed the species only in the south- distinctive appearance that hunters and others ern half (Figure 1). Vietnamese hunters com- remember for years the location and the de- monly cross the border and some of the tails of a killing or sighting. Because villagers specimens examined by Dung et al. (1993) in usually consume all edible parts of a carcass, Vietnam may have been killed in Laos. including the skin, and domestic pigs and Villagers also informed us that they had sold dogs dispose of the bones, physical evidence their saola horns to Vietnamese. of a killed saola does not persist for long; how- Figure 1 shows 23 localities where local peo- ever, on occasion the horns, sometimes with a ple sighted or killed saola; about half the part of the skull, are nailed to a hut wall and records are from 1990 onward. The records these were measured. The horns of 10 saola, cluster in or near the northern end of the con- some attached to the top half of the skull, as servation area, partly because our surveys well as the rotting hide and one hoof of an were mostly done there and partly because adult female were examined. the species appears to become scarcer to the south. For example, saola were once found around the village of Navang, but only one Distribution animal has been killed there in recent times, about 6 years ago. Visits to the south-eastern The saola's known range in Vietnam extends portion and along the southern boundary of from the Song Ca River at about 19°25'N, the conservation area indicated that most vil- 104°05'E south to about 18°05'N, 105°50'E lagers are unfamiliar with the saola or had along 225 km of the Annamite Mountains. It heard of its occurrence to the north. We were encompasses about 4000 sq km primarily of told that saola tend to concentrate in certain 108 © 1995 FFPS, Oryx, Vol 29, No 2 Downloaded from https://www.cambridge.org/core. IP address: 170.106.35.93, on 26 Sep 2021 at 17:33:16, subject to the Cambridge Core terms of use, available at https://www.cambridge.org/core/terms. https://doi.org/10.1017/S0030605300020974 THE SAOLA OR SPINDLEHORN BOVID PSEUDORYX NGHETINHENSIS IN LAOS LAOS THAILAND Saola records 1990-94 \ \ Thakhek \ Saola records 1960s-80s \ \ A "\ Known range in Vietnam %.._> I 25 50 104 I Figure 1. Distribution of saola or spindlehorn bovid in Laos and Vietnam. The data for Vietnam are based on the map in Dung et ah (1993). localities, leaving others unoccupied. If so, an understorey of saplings, bamboo, and pockets of animals may exist in the palms. About half of the records were at Conservation Area along the Vietnam border 500-1000 m a.s.l. and the rest up to about 1400 where villagers seldom go. m. Although the species is usually encoun- Most of the records come from steep but not tered in primary forest, it may frequent sec- precipitous mountains covered with a closed ondary growth. Dogs flushed a female with canopy of evergreen broad-leaved forest and young from a thicket near Nakadok and © 1995 FFPS, Oryx, Vol 29, No 2 109 Downloaded from https://www.cambridge.org/core. IP address: 170.106.35.93, on 26 Sep 2021 at 17:33:16, subject to the Cambridge Core terms of use, available at https://www.cambridge.org/core/terms. https://doi.org/10.1017/S0030605300020974 G. B. SCHALLER AND A. RABINOWITZ Table 1. Horn measurements of Length of Circumference Width between saola longest horn of horn base horn tips Sex* (cm) (cm) (cm) Female 9.5 6.4 6.8 Male 18.8 8.4 - Male 36.2 12.2 11.0 Male 39.5 12.1 8.2 Male 45.5 13.0 6.0 Female 45.0 11.8 - Female 45.1 11.0 3.5 Female 50.4 11.2 11.5 Unknown 42.6 11.2 8.7 Unknown 49.5 10.8 18.4 * The sex of specimens was determined through questioning either the hunter who killed the animal or a second party who had direct knowledge of the kill. Our questioning revealed that the first two animals in this list were subadults and the rest were presumed adults. villagers clubbed the young to death. al. (1993, 1994) provide a partial description of Two old records are from a considerable the saola. On the basis of examining fragmen- distance west of the conservation area and tary specimens we provide additional infor- two are to the south. These four are from mation that helps to clarify the phylogenetic karst, a rugged topography of Silurian lime- position of the species within the subfamily. stone consisting of great grey slabs of rock, The saola may weigh up to an estimated 100 serrated ridges and sheer isolated domes with kg and reach a shoulder height of 80-90 cm forest draping the base and the ravines. Karst (Dung et ah, 1993). It has a compact neck and at low altitudes tends to be dry, covered with body, but the head is rather delicately shaped semideciduous or deciduous forest and scrub, with a narrow muzzle and arched nasal bones.