Former range

The former range of the species consisted of vast deserts, which were linked by gravel corridors and plains. Basis for the conservation programmes is The National Commission for Wildlife Conservation and Development protected area system plan (Child & Grainger, 1990.) Details: status of areas of interest, physio-geography, management objectives.

Release

• Followed feasibility studies.
• Founder Oryx from a World Herd arrived in Jaaluni 1980.
• Two years of captive management.
• 1984, 1988, 1995 further release of founders: total = 40

1982

• 10 animals released January, provided with feed and water.
• New releases began to slowly explore the desert.
• After rainfall in August it moved 20 km, switching to feed on desert grasses and herbs.

1984

• A second herd of 11 released. The desert was dry, the herd stayed put, by June was joined by the first herd.
• Seldom mixing they remained for 24 months in Jaaluni area.
• r = 0.22; slow because of drought, and sterile dominant founder male monopolising fecund females.

1986

• p = 31.
• Wide spread rainfall
• Both herds moved 50 km to fresh grazing.

1987-89

• r = 0.35 p reaches 92.

1987

• Sterile male castrated, losses dominance shortly after.

1992

• First prolonged drought since 1986, no supplementary feed.
• Youngest and oldest increased mortality mainly due to malnutrition, dietary protein low.
• Drought broken, widespread conception, clear seasonal trends of reproduction absent.

1994

• Heavy rainfall in south east corner led to expansion of range;
• 57% female. Skewed sex ratio was typical; males are often solitary and more difficult to locate.

1995

• 16% ageD less than 1 year, r=0.25.

1996

• P= 400?

Poaching

17 years after first release wild population collapsed due to poaching.

1996 track evidence:

• Calves targeted then switched to adults. Poor survival rates?
• Adult female targets resulted in abandoned calves, some returned to Jaaluni for hand rearing.
• Method short high speed chases vehicles turning on targets until exhausted or knocked down.
• Oryx tends to run straight and avoid cover, easy to capture in open country.
• Fallen Oryx caught by hand or net, no cases of shooting, ear tags remove.
• Poached usually late afternoon, cover of darkness would allow escape, also moonlit nights.
• Dead Oryx abandoned by poachers... capture myopathy.

1997

• Population fell 330
• A proportion decreased with increasing population.

1998

• p=310, m:f=216:90 reflects,

  • targeting females for captive breeding programmes.
  • Increased competition amongst males for females with probable negative consequences for calf survival - competing males were more aggressive towards following calves.

• Aug 1998 Wild population no longer considered viable

  • all but 5 male Oryx removed from southern parts of sanctuary,
  • patrols withdrew to protect the few females central and north.

40 Oryx including a single breeding male, herded and chemically immobilised, returned to pre-released enclosure at Jaaluni. Bachelor herds common, est 20 breeding females in wild, most solitary or in small male dominated herds. Difficult to locate or effectively guard. Probable that most founder lineages are represented in the wild remnant herds; 11 f and 85 m. Further founder females required to speed up recovery.

Social organisation

June 1986 herds broke up, more dynamic hierarchal dominance based on mainly female groups and following calves, group size varied and frequently changed.

• Males left maternal groups at maturity.
• First signs of territoriality.
• Range = 12,000 square km, December 1989.

1990-92

• r=0.14
• fecundity high
• mortality of calves and adult males increased, primary cause aggressive males coinciding with increased territoriality.

Monitoring

• Strategy: detailed information of a sample. A monthly transect census.
• Individual identities of all Oryx known until 1993; accuracy of surveys were checked. Breeding performance, genetic profile, health screening. Sex ratio in calves.
• Herd dynamics: Low level monitoring of others, twice yearly surveys for numbers and structure.
• 20-30% of animals ear tagged to facilitate by mark-recapture method. Accuracy of mark-recapture technique improves with proportion of marked animals (Krebs 1989). Confidence limits increased.
• Daily patrols : rangers and light aircraft.
• Prediction of future populations based on observed births and deaths.

Genetic analysis

• Confirmed reintroduced population had less genetic variation than the aboriginal population (Marshall, 1998). Inbreeding coefficients from stud book data not associated with fitness components; although micro satellite DNA variation indicates both inbreeding and outbreeding depression associated with juvenile survival.
• Higher growth rates suggests these depressions were not major threats to PV.

Conclusion

• Threats increasingly demographic.
• Confidence limits enabled the declining popualtion to be monitored effectively.
• Sex ratio demonstrated targetted poaching.
• Success of reintroduction attributed to favourable bio-political conditions and adequate long term funding, recognised to be as or more important than biological factors for success (Kleiman et al., 1994).
• Feasibility study concluded hunting threat had been eliminated, and absence of security threat during early years of reintroduction supported this. Threat lay dormant.
• Poachers exploited demand outside the country, the primary threat.
• This programme testifies to the success of captive breeding programmes. This and the establishment of a second wild population in 1995 in the Uruq bani mar arid protected area, kingdom of Saudi Arabia (Ostrowski et al., 1998) shows that Oryx can be successfully returned to the wild.
• Re-habilitation of degraded habitats and control of hunting should produce more suitable areas for re-introduction.
• Meta-population strategy will secure long term survival for the species.
• The challenge is to protect the species in the wild.
• Project tested the ability of the animals to adapt and thrive in their ancestral habitat, several generations removed from the wild.

Captive- Breeding

• Captivities worldwide, 1,600 animals in 1992

• Saudi Arabia 28% died of TB: Sanitary measures taken, anti-biotic treatment, annual testing, '3 generation management', maintained even for the TB free herd.

  • 1. isolated breeding,
  • 2. hand-reared,
  • 3. mother reared offspring used for re-introduction.

• Reared with minimal contact with human beings
• The NWRC herd has the greatest diversity of all captive and wild herds
• Includes the world herd, Original Saudi, Qatari and Abu Dabbi lineages
• Capable of providing for large scale releases throughout Saudi Arabia
• New release sites were not ready: captive breeding of second generation animals had to be reduced
• MVP needed to conserve 90% of polymorphism after 200 years estimated at 250 B- generation Oryx.
• Some genetic lineages are under-represented. Breeding of these founder lineages is necessary.
• Genetic research and management continues

Re-introduction into Reserves

• Entire reserves in Saudi Arabia were fenced to exclude poachers and grazing livestock.
• Supported by government
• Remoteness and inaccessibility facilitate protection in some areas.
• Degraded grazing land recovered rapidly after fencing.

• Hunting is forbidden in 2 zones and controlled in a third zone,

  • 1. a special core area excludes human settlements, activities and livestock.
  • 2. A resource use reserve 5000 square km with regulated livestock use by locals.
  • 3. Controlled hunting reserve, activities apart from hunting are not controlled.

Field studies

• Metabolism and water requirements carrying capacities of protected areas alongside livestock grazing.
• Studies on behavioural recovery and reproductive physiology continue.

Maximised population genetics

• Avoiding artificial selection increasing effective population size,
• Reaching MVP as quickly as possible
• Equalisation of founder contribution.
• Sub-populations : there should be some differentiation, interactions should be allowed, and consider urban and agricultural development
• Number of metapopulations are specified as 2 in Saudi Arabia.

Threats

• Capture appears to be a very old tradition.
• need to enforce the hunting ban strictly.
• poaching, can the rangers be given policing powers.
• long term local participation and more benefits to the local people could help controls.
• Illegal trade might be prevented by flooding the market with captive bred Oryx but side effect might be rapid increase in poaching.
• Interspecific competition tolerable during times of good rain : ok, while the population is still small.
• Camel grazing affects distribution of Gazelles, maybe Oryx,
• Exclusion of livestock often not feasible - herdsmen consider these areas as their own.
• Habitat degredation depends upon numbers of grazers.
• Exclusion of domestic grazers is of doubtful long term conservation value.
• Regulations limiting livestock would be difficult to enforce during poor rain.
• Consistent grazing control requires agricultural reform.
• Non-fenced protected area management must consider the tribal social structures.
• Eco-tourism could be a management tool
• Accessibility of the area to vehicles and density of surrounding settlements.

• Wood fuel is a major source of energy for the Bedouin, the ban on tree cutting must be enforced .

  • Trees are the main source of shade for Oryx during the summer OR, AF management.

• Good winter rain results in large numbers of people entering the reserve to harvest edible fungus known locally as 'Fagga'.
• Carrying capacity may be exceeded risking disease in small area reserves. Social structure male competition.

Captive management problems are serious due to a lack of suitable release sites related to overpopulation, disease and fighting. Solution: Contraceptive control suggested.

Captive herds required to support wild herd and, in case of population collapse.