Individual elephant identification and monitoring in northern Kenya
The long term monitoring research being carried out in Samburu requires individual recognition of each elephant that enters the reserve. For this reason, it is vital that an accurate reference system exists to ensure that elephants are identified correctly by researchers in the field. Over 1000 individual elephants have been identified in the greater Laikipia-Samburu region, many of whom spend large amounts of time outside protected areas. Elephants dwelling in the greater Laikipia-Samburu region represent the largest population existing outside of protected areas in Kenya. An on-going individual identification study of the elephant population within the Samburu and Buffalo Springs National Reserves was started in November 1997 by George Wittemyer and has been continued by our researchers staying at our research camp in Samburu. The monitoring project gathers baseline information on demography, social structure, behavior, and ranging needs, yielding insights into population growth, dynamics, and history. Elephants within the study area are identified using characteristics such as sex, age, and features unique to the individual. Each elephant has unique ear patterns and tusk shapes, much like human fingerprints, which provide vital clues for identification. Also, individual elephants can be identified easily if they have particularly distinguishing features, such as a bad leg or other permanent injuries. An otherwise healthy animal must be identified primarily by differences in its tusks and the unique patterning of nicks and tears in its ears. These details change gradually over time, with tusks being worn down and new nicks appearing on the edges of the ears. However some aspects, like the patterning of blood vessels on the ears, are relatively immutable. Both side and frontal photographs of the ears and tusks of each elephant are taken, and drawings made to supplement the photographs and make future recognition easier. By collecting demographic data using an individual recognition file George was able to obtain an estimate of the total number of individuals in the area and gauge the basic population parameters. So far over 1000individual elephants have been identified. The identification of elephants in the field has previously relied on the observers’ memory and extensive, but aged, photo files. We are now replacing these files using Google Picassa as a database system containing ID photographs in digital format of each elephant.
The elephants are sorted into their family units and the photos are all labeled within the programme which can search for any elephant in the system by name or code number. The programme has also allowed us to modify older photos of elephants, for example adjusting contrast and brightness, to complement the new photos we are currently taking in the field. Most of the resident elephant families now have the full complement of ID images. For families which are more infrequent visitors to the reserve, priority is given to obtaining photos of the breeding females in the group. This is because the younger elephants can all be identified by associating them with their mother, rendering ID photos of their smoother ears and undeveloped tusks unnecessary. Some trips to the West (outside the reserve boundaries) have also enabled us to obtain ID photos of the non-resident bulls.
George also looked at the movement patterns of the elephants and estimated the proportions of resident and migratory/non-resident elephants using the reserves. Using a wildness/tameness reaction index he tried to identify potential risks to and stresses on the elephant population. The results showed that the elephant population utilizing Samburu and Buffalo Springs National Reserves are largely free-ranging and spend significant periods outside the protected area. The reserves themselves can not sustain the numbers of elephants in the region. It is therefore essential for ecological and demographic reasons that the population not be confined by fences in the future. Additionally, risks and stresses on the population are documented.
The elephants are sorted into their family units and the photos are all labeled within the programme which can search for any elephant in the system by name or code number. The programme has also allowed us to modify older photos of elephants, for example adjusting contrast and brightness, to complement the new photos we are currently taking in the field. Most of the resident elephant families now have the full complement of ID images. For families which are more infrequent visitors to the reserve, priority is given to obtaining photos of the breeding females in the group. This is because the younger elephants can all be identified by associating them with their mother, rendering ID photos of their smoother ears and undeveloped tusks unnecessary. Some trips to the West (outside the reserve boundaries) have also enabled us to obtain ID photos of the non-resident bulls.
George also looked at the movement patterns of the elephants and estimated the proportions of resident and migratory/non-resident elephants using the reserves. Using a wildness/tameness reaction index he tried to identify potential risks to and stresses on the elephant population. The results showed that the elephant population utilizing Samburu and Buffalo Springs National Reserves are largely free-ranging and spend significant periods outside the protected area. The reserves themselves can not sustain the numbers of elephants in the region. It is therefore essential for ecological and demographic reasons that the population not be confined by fences in the future. Additionally, risks and stresses on the population are documented.