Understanding elephant dynamics.
Tsavo Elephant Research, (formerly known as the Tsavo Elephant Conservation Trust) recognizes over 950 individual elephants in the Tsavo ecosystem. These include individuals in the Tsavo East National Park and on privately owned land in the southern region of the ecosystem between Tsavo East and West National Parks. Over 500 of these elephants have been monitored since 1989.
WildiZe provides funding for important data collection and research to better understand elephant family dynamics. Specific research has included wet and dry season forage patterns, population increase and decline, births/deaths, bulls and family structure.
The results of this research has provided tremendous insight into normalized herd dynamics and census data of elephants traveling through Tsavo. Migration routes and eating choices are better understood, along with areas of potential conflict between people and wildlife are identified. This data also supports rangers as they seek to understand and mitigate problems.
Project Web site: www.tsavoelephants.org
Objectives
Tsavo Elephant Research began in 1989. It is a non-interference research project monitoring the behavior of elephants in Tsavo. The research is based on known individuals - many of whom have been known for almost 20 years. Photographic identification of distinct features (tusks, ears, tail) are used to track known individuals.
Age-sex Structure
Monitor the number of males and females in 5- year interval age classes - newborns to older than 40 years.
Reproductive Status
Monitor the male reproductive status; age of bulls in musth, frequency of musth cycles, duration and season. Monitor the females age at the birth of their first calf, calf survival and calving interval.
Social Structure
Monitor seasonal and spatial group structure; lone bull, bull groups, families and mixed groups (families with a bull - older than 20 years of age). Monitor associations and behaviors between bulls and relationships between families.
Ranging Patterns
Map seasonal home range and boundary crossings between the National Park and adjacent privately owned land.
Environment
Monitor elephant’s utilization of natural and artificial water resources; map favored vegetation habitats. Monitor the impact of climate change on elephant population dynamics.
Human Impact
Monitor the impact of tourism, fires, poaching for ivory, injuries from snares, fencing and livestock encroachment on elephant behavior and the environment.
Elephants
In the late 1960s, there were approximately 35,000 elephants in the Tsavo region. This population has suffered two population crashes.
The first was the drought in the early 1970s when an estimated 6,000 individuals died and over the next 4 years with low rainfall and lack of vegetation weakened females and young elephants died. Unlike pregnant females, females nursing a calf or young calves, independent bulls were able to travel greater distances in search of vegetation and their mortality was lower.
The second crash was due to the illegal killing of elephants for their tusks. The large bulls who survived the drought were the first victims for their large and heavy tusks. When the remaining bulls were difficult to find, the large females were targeted (their calves died as a results) and then whole families. By the late 1980s, at the height of the ivory poaching era, about 6,200 elephants remained in the entire Tsavo region.
Elephant Range
Aerial surveys conducted in the mid-1960 and 1970s showed that the majority of the groups sighted were confined within the National Parks. With the onset of the rains these groups dispersed, but there was little indication of large scale migrations. Elephant seasonal range was influenced to some extent by the surrounding legal hunting areas, rainfall and the development of artificial water resources within the National Park
Study Site
The study site is 4,000km² and one-third of Tsavo East National Park. The northern boundary is the Galana River. The north-western boundary contains an open-ended electrical fence, separating wildlife and humans. The Voi River flows from west to east, across the center of the study site. The majority of the southwestern boundary is not fenced off to the elephants. However the elephants that move between the National Park and private land must cross the railway tracks and the main Mombasa-Nairobi road (a dangerous route - some elephants are killed when trying to cross).
Habitat
The environment within the study area is relatively flat terrain with a few hills to the northwest. The vegetation consists of Acacia-Commiphora, open grassland, riverines and bushland with shattered trees.
To the north of the study area, the Tsavo and Athi River converge to create the Galana River and is typically a permanent resource. The Voi and Mbololo Rivers, which are seasonal, are important dry season riverine areas, for food and shade and an important area where elephants dig for water in the dry river bed.
The natural pools in Ashaka, Punda Malia and Sobo within a short distance to the permanent Galana River provide water for the elephants and other wildlife during the dry season.
