Ostrowski S. & Bedin E. 2001. Arabian oryx re-introduction in 'Uruq Bani Ma'arid, Saudi Arabia: summary and update: January 2001. Re-introduction News 20: 16-17.

Full text: For the sixth consecutive year Arabian oryx (Oryx leucoryx) have been translocated from the National Wildlife Research Center (NWRC) in Taif, into the ‘Uruq Bani Ma’arid protected area on the south-western edge of the Rub’ al-Khali desert, also known as the “Empty Quarter" (Cf. 2-1997-013). Since 1995, 15 groups of Arabian oryx have been moved to the protected area. The mean group size per transportation was 9 animals (SD=± 2.1). The mean number of males per transportation was 4 (SD= +/-2.2) and the mean number of females per transportation was 5 (SD=± 2.3). Transportation time from the Taif pens to the ‘Uruq Bani Ma’arid pre-release enclosure ranged from 6.5 to 9.5 hours. All animals moved to ‘Uruq Bani Ma’arid were boma-trained for at least three weeks before transportation (Cf. 2-1995-003). Additionally, long-acting tranquilizers were used during most translocations although four groups comprising very quiet animals were not tranquilized. Boma-training was started three to five weeks before transportation. Every two days, each group was enclosed in an indoor pen for increasing periods of time, ranging from 2 to 24 hours. Progressively the oryx became accustomed to being moved into the crates. Eventually, twice to three times a week, each group was driven around the NWRC for durations of 30 mm to 2 hours. A long-acting tranquilizer was administered 72 hours before the scheduled transportation.

Translocation

In 1999, 21 (10.11) third generation oryx from the National Wildlife Research Center captive breeding program were translocated. The animals were moved by military airplanes in two separate groups: the first shipment arrived on the 31st of January, the second on the 21st of February. No deaths or injuries occurred. Both groups were released into the wild on the 5th of April. All released animals were fitted with numbered collars, none were given radio-collars. Animals were assembled since birth time, long time social cohesion being an important factor to secure a risky transportation. As already described by Dr T. Wacher (Cf. 2-1998-010) for animals released last year, it was evident that for the first month the newly released animals were nervous, compared to established oryx. The released animals remained together as separate herds during the first ten days after release. They were periodically joined by wild born animals. One month after release, the group had become split into small herds, and some individuals had joined settled animals. Several animals lost condition. Five individuals remained in poor condition during the summer, ultimately three of them died. Deaths was the result of very difficult environmental conditions (‘Uruq Bani Ma’arid area has not received consistent rainfalls since spring 1996) and possibly also because of competition with settled mature animals. In 2000, 18 (11.7) third generation oryx from the National Wildlife Research Center captive breeding program were translocated. The first herd of 8 (4.4) oryx was transported on the 1 8th November, and the second of 10 (7.3) oryx, on 25th of November. Both herds were released on 18th December. Translocation method followed the previous procedure. All released animals were fitted with radio-collars. On the contrary to previous releases animals seemed to be very tame and several did not adapt to their new environment. At the end of January 2001, three animals had died. Since they were usually found several days after the supposed date of death, the exact cause of death could not be determined. However, because they were observed in poor body condition several days before their supposed date of death, we believe that they ultimately died of dehydration/ starvation. Since 1995, when the first releases took place in the “Empty Quarter”, 139 oryx (68.71) have been translocated. One hundred thirty one of these animals were captive-born, whereas eight came from the Mahazat as-Sayd protected area. Ages of the translocated oryx ranged between three months to six years at the time of arrival. Nineteen (13.6) deaths among re-introduced animals have been recorded in the reserve since the first arrivals. Of these, six (6.0) are thought to have been the results of fights between males. Three (2.1) have been poached. Seven (3.4) individuals died because of unadaptation to environmental conditions. The causes of three other deaths (2.1) are unknown. Deaths among wild born animals are less readily documented as carcasses are never or rarely recovered.

Poaching

This has become a significant cause of Arabian oryx mortality in the protected area accounting for 30% of reported deaths since 1991i. Six animals were poached (22% of known deaths). The first case occurred during autumn 1998, the oryx was unidentified. On the 3rd of April 1999 a second poaching case occurred, on a captive-bred animal. In October 1999 a third non identified animal was killed. During 2000 two captive-born and one wild-born oryx were killed. Blood, cartridges, vehicle tracks and foot prints were systematically found at the sites by rangers. All poaching events except one occurred in the north-east, more accessible part of the reserve. Animals were chased with a vehicle until exhausted, then repeatedly shot and slaughtered in-situ. Illegal hunting is to be considered as a recreational activity for the poachers. According to the rangers and the police it is likely that the same poaching team was responsible of four of the six known cases. The poaching team seemed to be composed of three individuals most probably coming from Wadi al-Dawasir or El-Assil cities, located respectively 200 and 35 km north of the protected area. Although poaching problem will probably not be solved until the poaching team is identified, recent measures (creation of a new ranger camp in the north-east of the reserve) will hopefully help to control a problem which remains still at an embryonic stage.

Conclusion

Although, productivity of the released animals is still positive, the oryx population has increased more slowly since 1998 than between 1995 and 1997. It has been admitted that drought conditions that have prevailed in the protected area since end of 1997 have had a negative effect on the growth’ rate, by increasing mortality rate and decreasing calving rate. This trend should continue as long as environmental conditions stay sub-optimal. In 2000 the slight increase of the population was mainly due to re-introduction of 18 new individuals. By December 2000 the population of free-ranging oryx was estimated to number nearly 210 animals. Monitoring of the Arabian oryx re-introduced herd is done by Mr Eric Bedin, National Wildlife Research Center, and remains a priority.

#2-2001-003