Distribution and Status of Nubian Ibex in Saudi Arabia
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Distribution and status of Nubian ibex in Saudi Arabia Khushal Habibi and John Grainger Despite increased hunting pressure accompanied by habitat degradation, the current distribution of Nubian ibex Capra ibex nubiana in Saudi Arabia closely resembles that of historical record and spans a wide diversity of habitat types. Efforts are under way to conserve the species and two special ibex reserves have been created. Introduction by royal decree in 1986. An important part of the Commission's pro- This paper reports recent records of the gramme has been to locate relict wildlife pop- Nubian ibex in Saudi Arabia, where wildlife, ulations and evaluate the status of their habi- as in most of the Arabian Peninsula, has tats throughout the Kingdom. The eventual declined considerably in recent decades. aim is to establish a system of wildlife reserves Although this has affected mammals in gener- in which the large mammal fauna in particular al, it has been most serious for large ungu- may be rehabilitated. lates. The Arabian or white oryx Oryx leucoryx The Nubian ibex, a species of major interest became extinct in the wild in the early 1960s to the NCWCD, was widely distributed in the (Dolan, 1976) and the same fate appears to Arabian Peninsula (Philby, 1933; Carruthers, have befallen the Saudi dorcas gazelle Gazella 1935; Raswan, 1935; Schwarz, 1935). The cur- dorcas saudiya, while the sand gazelle G. rent status and distribution of the species in subgutturosa marica and the mountain gazelle Saudi Arabia were uncertain until recently G. gazella have been reduced to relict popula- with few confirmed sightings (Harrison, 1968; tions (Habibi, 1986). Gasperetti, 1978). The principal causes for this extirpation of wildlife in Saudi Arabia lie in the recent accel- eration of habitat destruction, chiefly through Methods overgrazing by livestock, and excessive hunt- ing. Severe competition for grazing from Since 1987 NCWCD field staff have under- increased numbers of domestic stock has taken aerial and ground surveys to locate ibex caused a dramatic contraction in the formerly in the western and central regions of Saudi extensive range of most of the Arabian ungu- Arabia, which constitute the historical range lates, which are now restricted to 'islands' of of the species. Specific survey locations were marginal habitats where they maintain a tenu- identified by reference to historical records ous existence. and also on the basis of undocumented Major wildlife conservation initiatives have reports, for example by field geologists, heli- taken place in several countries of the Arabian copter pilots and information received in the Peninsula in the last decade, of which the field. Aerial surveys, using Bell 212 helicopters Omani Arabian oryx reintroduction pro- provided by the Royal Saudi Air Force, were gramme is perhaps the best known. In Saudi made over rugged terrain generally favoured Arabia the major efforts to reverse the decline by ibex. Ground traverses were used to gauge in wildlife have been initiated by the National range conditions and habitat utilization in Commission for Wildlife Conservation and those areas where ibex were found to be resi- Development (NCWCD), which was created dent. 138 Downloaded from https://www.cambridge.org/core. IP address: 170.106.33.19, on 27 Sep 2021 at 21:14:05, subject to the Cambridge Core terms of use, available at https://www.cambridge.org/core/terms. https://doi.org/10.1017/S0030605300033858 NUBIAN IBEX IN SAUDI ARABIA Results only one population is known to survive in the extensive Tuwayq escarpment (site 1, Figure 1), although ibex were more common Nubian ibex distribution there in the past. Fifteen extant ibex populations have so far been located in Saudi Arabia. The animals are Ibex habitats largely concentrated in the mountains of the Arabian shield in the west of the country, with The distribution of the Nubian ibex in Saudi isolated groups located in the northern, north- Arabia spans a wide diversity of habitat types central and central regions (Figure 1). (Table 1). The relict population found in the The currently known distribution of ibex, central Tuwayq occupies low-altitude, dissect- with some exceptions, closely conforms with ed escarpments of sedimentary rock, which that of historical record. The confirmed range are treeless, except in narrow canyons, and has been extended in the south-western where precipitation averages 50 mm a year. By mountains, but there appears to have been contrast, ibex in the south-west of the country some reduction of the range in the northern occupy juniper-dominated mountain summits border areas. The most dramatic contraction, with elevations in excess of 2000 m, and where however, has been in the central region, where rainfall averages over 350 mm a year. Table 1. Ibex observations made during reconnaissance surveys (1987-1989) in Saudi Arabia Average precipitation Maximum mm/year (min. Location altitude (m) 6-year record) Physiography 1. Hawtat bani Tamim 500 52.6 Sedimentary cuestas 2. Wadi Tiyah 2300 369.0 Crystalline montane 3. Hema Fiqrah 1500 100.0* Crystalline montane 4. Jabal Qaraqir 1200 50.0t Sandstone pinnacles 5. Jabal Salma 1100 108.0t Dissected granitic plutons 6. Jabal Aja 1200 108.0t Dissected granitic plutons 7. Jabal Irnan 900 44.7 Sandstone hills 8. At Tubayq 1000 33.0 Sandstone cuestas 9. Jabal al Gharir 1400 47.5t Crystalline montane 10. Jabal alKalab 1700 47.5t Crystalline montane 11. Jabal Lawz 2580 44.7t Crystalline montane 12. Hisma 1821 44.7t Sandstone mesas 13. Hawsal 1502 44.7t Sandstone mesas 14. Jabal Dibbagh 2268 44.7t Crystalline montane 15. At-Tawil 890 100.0* Sandstone massif * Estimated precipitation, no records, t Closest station record. 139 Downloaded from https://www.cambridge.org/core. IP address: 170.106.33.19, on 27 Sep 2021 at 21:14:05, subject to the Cambridge Core terms of use, available at https://www.cambridge.org/core/terms. https://doi.org/10.1017/S0030605300033858 ORYX VOL 24 NO 3 JULY 1990 25' 20' 15' 50° 55° Figure 1. Distribution of ibex in Saudi Arabia. Open circles indicate sightings by field survey personnel dur- ing 1987-1989. Closed circles show recent observations, reports and historical sightings. Habitat conditions for ibex in general were in a year-long study of the Walia ibex Capra found to have been less degraded than those ibex walie in the Simien Mountains, observed of other wild ungulates. All the sites were only two instances of these ibex drinking characterized by difficult terrain, which tends water, although the study site receives more to limit access to livestock, and the vegetation, than 1500 mm rainfall a year. It is interesting in terms of structure and species diversity, has to note, in this regard, that in Arabia hunters remained relatively intact in these areas. traditionally used stone hides overlooking The general ecological requirements of water holes to lay in wait for ibex. Nubian ibex are, however, poorly understood, especially with regard to food plant selection, habitat preferences and water requirements. Population status The latter is of particular interest as the avail- It was impossible to determine the status of ability of permanent water sources is uncer- Nubian ibex populations in the Kingdom dur- tain in two of the most arid sites supporting ing reconnaissance surveys. The animals ibex (sites 7 and 8, Figure 1). Nievergelt (1981), appear to be locally distributed throughout 140 Downloaded from https://www.cambridge.org/core. IP address: 170.106.33.19, on 27 Sep 2021 at 21:14:05, subject to the Cambridge Core terms of use, available at https://www.cambridge.org/core/terms. https://doi.org/10.1017/S0030605300033858 NUBIAN IBEX IN SAUDI ARABIA their range at low density levels (Table 2). The Due to observation difficulties in the rugged 51 observed groups had a mean group size of terrain, the long flight distances of the ani- 3.4 animals, although large groups, of up to 26 mals, and their propensity to hide when dis- animals, have been reported by NCWCD turbed, it was impossible, in all instances, to rangers (Table 2) in the two locations where ascertain sex-age ratios for the observed hunting is now prohibited. groups during the aerial surveys. Where Little information is currently available on sex-age ratios could be determined, groups the social organization of Nubian ibex. were found to be composed of either a mature Harrison (1968) reported that the animals male (7-10 years) with several females and occur in small groups, although aggregation juveniles, or groups of subadult males and into larger groups, especially during the rut- individual adult males. Although juveniles ting season, is common among caprids (Geist, were observed in almost all localities it would 1971; Schaller, 1977). In this study variation in be premature to speculate on the long-term group size was small, with most observed viability of these various ibex populations. groups being close to the mean, although habitat conditions in terms of food plant avail- ability were markedly different. The small Conservation requirements group size, therefore, may be a social feature of this subspecies rather than an indicator of In contrast to other ungulate species in Saudi habitat or carrying capacity. A similar mean Arabia, the Nubian ibex appears to have sur- group size was reported for Walia ibex by vived, albeit in enclaves, in most parts of its Nievergelt (1981). known historical range. The species continues to be threatened by habitat degradation, par- ticularly through extension of roads, which Table 2. Numbers of ibex seen during reconnais- allows for further encroachment by livestock sance surveys (1987-1989) in Saudi Arabia and other development pressures in and around its remaining refuges. The continued No. groups No. displacement and isolation of ibex popula- Location observed observed tions will further limit opportunities for dis- 1.