Status of a re-introduced population of threatened Arabian sand gazelles in SW Saudi Arabia: management lessons from an aridland re-introduction

Summary

The Arabian sand gazelle (Gazella subgutturosa marica), locally known as reem, had been extirpated from southwest Saudi Arabia through excessive hunting before Saudi Arabia's National Wildlife Research Center reintroduced captive-bred stock from King Khalid Wildlife Research Center and Al Sudairy Gazelle Research Center into the fenced, 2,224 km2 Mahazat as-Sayd Reserve, established in 1988 to also host Arabian oryx, Houbara bustard and red-necked ostrich. Between February 1990 and June 1993, 135 gazelles were translocated in five groups, quarantined, vaccinated and held in a 25-hectare pre-release enclosure for 10 to 14 months before five soft releases took place between May 1991 and February 1994, timed to favorable vegetation and calf weaning. All seven initially radio-tagged females gave birth within a year of release, and by the early 2000s the population had grown into the thousands, peaking above 1,600 in some years, though annual counts and mortality both fluctuated sharply, including mass die-offs during droughts, since the reserve's fence blocks the species' natural long-distance movement to find food, and dead animals were repeatedly found clustered near the boundary fence and under shade trees. A 2008 strategy now calls for capturing and relocating surplus animals to manage numbers against carrying capacity. Major difficulties included maintaining long-term monitoring, lacking mass-capture skills, and no genetic diversity studies of the released population. The project rates itself Partially Successful, citing an established self-sustaining population that nonetheless suffers recurring large-scale drought mortality inside the fenced reserve.