Translocation of bulls and family groups
The pilot needs to herd the group to a safe clearing in the bush, usually near an access road, and synchronizes this with the time it takes for the drugs to take effect. The first sign of a successful dart will be after 3 minutes when the elephant’s tail drops down and remains limp. Young calves remain with their mothers and as such, are only darted from the ground after the larger family members are immobilized. Skilled flying keeps the herd from bomb-shelling after the darts are in, as the animals only respond to the helicopter for 5 to 6 minutes once darted. Generally it will take 8 or 9 minutes for the animal to be fully affected or approachable, and the pilot needs to ensure that each animal is accounted for and that its recumbancy position is monitored when it goes down.
Collaring and Elephant Range Studies
In order to fit a GPS or Cell Phone collar, individual animals are darted. Adult bulls are usually solitary and are easy to work with. Data transmitted via the collars has helped conservationists plot the range and movements of individual bulls. Correlating these movements with rainfall distribution over larger areas, patterns have emerged showing a trend of the impressive journeys that elephant bulls make.
In order to monitor the movements of family groups, one elephant cow in the group will be collared. Collars are especially helpful if the cows are to be contracepted on an annual basis - locating a group is guaranteed as they can not hide away from the helicopter, and each group can be located quickly, saving on flying time.
Elephant sterilization Procedures
|Bush surgery: the anaethsitized elephant bull is carefully prepared for surgery. Every precaution is made to ensure that the operation is a success and after only 2 to 3 hours of surgery, the immobilizing drugs are reversed and the elephant returns to the bush.|
One solution to over population of elephants in smaller reserves may lie in the permanent sterilization of selected individuals. Vasectomised elephant bulls maintain normal hormone levels and as such, their breeding and social behaviour remains unchanged. These bulls will continue to go into musth, will mate without being fertile and will maintain their social standing with other elephants. On-going research into anatomy and the associated, advanced and complex surgical procedures involved is being conducted by specialist overseas vets from Disney Animal Programs, the pioneers of this project, in collaboration with various universities, local wildlife specialists and private elephant owners in South Africa.
Used on elephant cows with great success, the vaccine called pZP, or porcine zona pellucida, is non-hormonal and once administered stimulates an immunological response in the animal. When the elephant cow ovulates an antibody layer forms around the egg and blocks the sperm receptor sites preventing fertilization from taking place. For success, the most important factor is to have a clearly defined elephant management plan outlining the reserve’s carrying capacity, options and long term objectives with a sound elephant identification and monitoring program.
Target animals, consisting of reproductively active females, need to be clearly identified and profiled after which a tailored contraceptive program is implemented to maintain a healthy and viable population. Drop out darts administering the pZP vaccine have a dye release mechanism, marking the cows to ensure that they are not accidentally re-darted.