The Tsavo Mobile Veterinary Unit

Field Report - September 2005

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Between August 24th and September 28th, the unit participated actively in the translocation of 150 elephants from the Shimba Hills National Reserve in Kwale District to the northern part of Tsavo East, a distance of about 350km. This was the first phase in the planned movement of 400 elephants from Shimba to Tsavo. The objectives of the translocation were: 1. To decongest and therefore reduce habitat destruction in the Shimba Hills which with an area of 250 sq. km and a population of over 700 elephants, had more than three times its carrying capacity. 2. To mitigate the rampant elephant-human conflict around Shimba Hills. The electric fence constructed around the reserve to restrain the animals within the reserve has not helped much. Most of the 120km fence has been run down by the animals in their quest to go out of the confinement to look for food. Elephants been intelligent have devised ways of destroying the fence without being electrocuted. Meanwhile, there are plans to replace the fence with a modern one that will contain the remaining elephants. 3. To restock the northern part of Tsavo with a view to open it to visitors. Tsavo is vast and has sufficient capacity to sustain the growth of the translocated population. Most of this capacity is underutilised after elephant numbers plummeted in the 70s and 80s due to poaching. Security has now been improved. The funding was entirely by the government. CAPTURE TECHNIQUE A pre-translocation monitoring by two scientists was done for an year to identify discrete family groups ideal for the translocation. The capture and loading were done in the neighbouring Mwaluganje Community Elephant Sanctuary where the terrain and vegetation cover is relatively better compared to Shimba.

Hydraulic self loading truck for recovering small sub-adults

A vehicle with one of the scientists would be sent out first thing in the morning to locate the elephants earmarked for the translocation before the chopper with the darting vet and the other scientist would get airborne. When they could not find suitable groups, the chopper would be used to search and identify the earmarked groups. Once an earmarked family was located, the chopper would herd it gently to a suitable area for darting and recovery.

Recovery process in progress

Darting was done using the Palmer Cap- Chur® long-range rifle and .22 blank cartridges. Appropriate doses of Etorphine Hydrochloride (M99®) combined with hyaluronidase to quicken the absorption was used as the immobilising agent. The darting sites preferred were the hindquarters and the rump. When darting a family group, a variety of M99® darts were prepared and labelled in advance for three age groups; adults (16-17mg), sub-adults (10mg) and young ones (5mg). They would be darted in quick succession starting with the matriarch so that it would act as an anchor for the other family members. The other older females were darted next, followed by the sub-adults and lastly the young ones. The ground team was called in after all the animals went down. Each vet with a security ranger was assigned an animal to monitor and ensure stable anaesthetic state until the animal was recovered.

Monitoring an immobilised elephant

He/she also collected various biological samples to help determine the health profiles of all translocated animals. Matriarchs were fitted with a radio collar to enable monitoring of the family after release. The equipment and personnel available was enough to recover up to five animals at once. Matriarchs and the very young were recovered first. The recovery times for family groups ranged between 1½-2 hours. Top-up doses of M99® at ¼ of the original dose of M99® used were administered if the narcosis became light before the animal was recovered.

A self loading tipping trailer used to recover adults

Lightness of narcosis is manifested by an increase in respiratory rate and depth, increased frequency and strength of trunk movements, increased frequency of ear movements and sometimes paddling of the feet. The family groups captured ranged between 5-9 individuals.

A truck fitted with self loading cranes for recovering big sub-adults

The transportation truck had a container with two compartments that could carry up to 12 elephants, six animals in each. When two families were captured in a day, each was loaded into a separate compartment and released separately in Tsavo. The maximum number captured in a day was 12. Bulls were darted with 18-20 mg of M99® combined with 5,000 IU of hyaluronidase. They were recovered and transported individually. Reversal of narcosis was done with Diprenorphine Hydrochloride (M5050®) at three times the dosage of M99® used, administered intravenously into an auricular vein. Some additional M5050® was also given intramuscularly to counter re-narcotisation, which can cause recumbency during transportation. Just before the administration of the reversal agent, an appropriate dose of a tranquilliser (Azaperone tartarate) was administered intramuscularly to calm the animals during transportation.

At left is the recovery crate and at right the transport container

Animals were transported soon after recovery. Hourly stops were made on the way to check on their condition. Aggressive and over-excited animals were given top-up doses of the tranquilliser using a pole syringe. CONCLUSION The operation was rated very successful. The mortality of six (4%) experienced was very low and far below our earlier experiences and what has been documented in other countries. Some of the animals that died were discovered to have deep-seated infections in the chest and abdominal areas from spear wounds that were not obvious before immobilisation. These compromised them a lot. Some died after they fell in bad positions in difficult terrains that compromised breathing.