Have Relocations Been a Successful Management Tool for the Conservation of Oribi Antelope in Kwazulu-Natal?

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Have relocations been a successful management tool for the conservation of oribi antelope in KwaZulu-Natal?

Savanna Science Network Meeting: March 2016

Tamanna Patel, Dr. Adrian Shrader, Dr. Keenan Stears, Dr. Ian Little Oribi (Ourebia ourebi)

• Highly specialized antelope

• Grassland requirements

• Numbers are declining in South Africa • Habitat loss & fragmentation • Illegal hunting & poaching

• Current status: • Vulnerable

Oribi Working Group

• Monitor oribi population numbers through annual oribi surveys

• Aims to promote the long term survival of oribi in their natural grassland habitats

• What is a relocation? • Movement of an animal or population of animals from an area where they are currently threatened to a more suitable area

• Successful relocations • Arabian oryx • White rhinoceros • Springbok Successful Relocation

• Results in a self-sustaining population • Births observed every year • Increase in population number

• Prior to relocation: • Basic set of criteria should be met: • Aims of the relocation should be defined clearly • Assessment of habitat suitability should be conducted

• Post-relocation: • Long-term monitoring over several years

Oribi Relocations? Key Questions

1. What is the success rate of previous oribi relocations in KwaZulu-Natal? 2. Have relocations been a successful conservation tool for oribi? 3. What are the factors driving the success/failure of these relocations? 4. How can the success of relocations be improved in future? Data Collection

• 10 sites in KwaZulu-Natal with relocated oribi

• 10 points to consider before any relocation (Pérez et al. 2012)

• Trends at each site → Success/fail

• Factors influencing success/failure → Additional questions

Pérez et al. 2012 1. Is the population under threat? 2. Have threatening factors been removed/controlled? 3. Are relocations the best tool to use? 4. Are risks for the target species acceptable? 5. Are risks for other species/ecosystem acceptable? 6. Effects of the relocation acceptable to local people? 7. Does the project maximize the likelihood of establishing a viable population? 8. Does the project include clear goals and monitoring? 9. Do enough economic and human resources exist? 10. Do scientific, governmental & stakeholder groups support the relocation?

6 No. of sites of sites No. 5

4 1 2 3 4 5 6 7 8 9 10 Points to consider (Pérez et al. 2012)

The number of sites that considered each point before any relocation 10

6 No. of sites of sites No. 5

4 1 2 3 4 5 6 7 8 9 10 Points to consider (Pérez et al. 2012)

The number of sites that considered each point before any relocation Points that were overlooked at many of the sites:

• Have threatening factors been removed or controlled?

• Are risks for the target species acceptable?

• Does the project maximize the likelihood of establishing a viable population?

• Does the project include clear goals and monitoring?

• Do enough economic and human resources exist? Success or Fail? 9 8 7

5 4 3

No. of of Sites No. 2 1 0 Increasing Decreasing Stable

Population Trend Number of criteria initially considered vs. Lambda

2.0

1.5

1.0

0.5

Population growth rate (lambda) 0.0 5 6 7 8 9 10

Number of criteria considered Factors driving these trends

• A model selection procedure based on small- sample corrected (second order) Akaike’s Information Criterion (AICc) values. • Generalized linear model: • Gamma distribution and a log link function

• Best fit model (lowest AICc value): • Oribi population size • Suitable habitat • Stocking rates • Suitable habitat x stocking rates Population size, suitable habitat, stocking rates

2.5 2.5

2.0 2.0

1.5 1.5

1.0 1.0

0.5 0.5

0.0 0.0

Population growth rate (lambda) Population growth rate (lambda) 0 10 20 30 40 50 0 500 1000 1500 Oribi population size Suitable habitat (ha)

1.6 1.4 1.2 1.0 0.8 0.6 0.4 0.2 0.0 Population growth rate (lambda) 0 1 2 3 4 5 6

Stocking rate (ha/AU) Interaction between suitable habitat available & stocking rates vs. Lambda

1.0

0.8 Key Lambda (λ) 0.6 -0.2 0.0 0.4 0.2 0.4 0.2 0.6 0.8 0.0 1.0 -0.2 1

2 Population growth rate (lambda) rate growth Population 200 3 400 600 4 Suitable habitat800 (ha) 5 1000 1200 1400 1600 Stocking rates (ha/AU) Conclusion

• What is the success rate of previous oribi relocations in KwaZulu-Natal? • Relocation success of 10%

• Have relocations been a successful conservation tool for oribi? • No, but they can be successful • Require proper management prior to and post- relocation • Monitoring is very important: • Directly after the relocation • Long-term monitoring plans

Conclusion

• What are the factors driving the success/failure of these relocations? • Oribi population size • Availability of suitable habitat • Stocking rates of other mammalian herbivores

• How can the success of relocations be improved in future? • To use the 10 points as a basic criteria prior to any relocation • To monitor oribi relocations over several years to be able to determine success/fail Management Recommendations

• Intermediate sized populations should be relocated (>18 individuals in new area)

• High availability of suitable habitat in the new area (>800 ha)

• Stocking rates of 3.5 ha/AU • Recommended by the different Bioresource Groups from the Department of Agriculture