Implementing immunocontraception in free-ranging African elephants at Makalali conservancy

Area of Science:

• Wildlife Management
• Reproductive Biology
• Veterinary Immunology

Background:

• Elephant population management requires humane and effective contraception methods.
• Traditional methods like relocation and immobilization cause significant stress and disruption.
• Long-term, minimally invasive strategies are needed for sustainable elephant population control.

Purpose of the Study:

• To evaluate the efficacy of porcine zona pellucida (pZP) immunocontraception in controlling elephant population size.
• To assess the implementation costs and efficiency of pZP contraception programs.
• To determine the impact of pZP contraception on elephant social and reproductive behavior.

Main Methods:

• Initiation of an immunocontraceptive program using pZP vaccine in a free-roaming elephant population.
• Comparison of ground versus aerial vaccination delivery methods.
• Monitoring of social behavior, reproductive status, and population dynamics.

Main Results:

• pZP immunocontraception effectively controlled elephant population growth.
• Aerial vaccination minimized herd stress and allowed rapid resumption of normal behavior.
• Implementation costs ranged from R880-R1000 per elephant per year (in 2005).
• A single vaccine administration rendered non-pregnant elephants infertile.

Conclusions:

• pZP immunocontraception is a feasible and practical alternative for elephant population management.
• Aerial mass-darting is an efficient delivery method, suitable for large populations.
• Immunocontraception, as part of a long-term strategy, significantly aids in controlling elephant population growth rates.