Spatial distribution of savannah large mammals in relation to oil exploration drilling in Murchison Falls National Park, Uganda

Abstract

Oil and gas exploration disturb wildlife habitat. However, little information is known in regard to large mammal species in Murchison Falls National Park. This study monitored spatial distribution of Elephants, Buffaloes, Giraffes and Uganda Kobs prior to drilling, during and post drilling at two selected well pads JOBII EAST 4. The study aimed to provide information on large mammal species spatial distribution in response to oil disturbance effects. Data were collected by walking along 2km transects, counting large mammals with increasing distance from oil well pad fences. Disturbance from oil activities was measured by comparing number of people, vehicles and running machines at well pads in pre, during and post drilling periods. Habitat area was measured in every 100m multi-buffer rings at each oil pad in ARC MAP 10.0. This allowed for analysis of relationships between wildlife response and habitat type around oil well pads. Trends in large mammal distribution patterns along an increasing distance gradient from well pads were explored using regression model procedures in R.10.0 statistical program. Large mammal response patterns to drilled well pad and one without differed significantly with varying levels of disturbance. The results show significant differences in disturbance levels between oil well pads in pre drilling, during and post drilling survey periods. Elephants and Buffaro abundance increased in areas quite far away from the disturbance at JOBII EAST 1 (i.e. >1000m) during drilling. The abundance of giraffe and Uganda Kob were high closer to the pad during drilling. The study also revealed a significant positive relationship between animal spatial distribution and habitat types within distance intervals at both oil well pads. Given the evidence of disturbance on animal movement around oil well pads, there is potential for wildlife populations to concentrate in areas far off from oil activity sites with further oil operations in the Park. The disturbed large mammals are likely to shift from habitats around oil pads to the ones away from drilling sites. Development of new oil drilling well pads within critical wildlife habitats should be minimized. The disturbance effects on wildlife distribution should form a guide in setting management strategies to balancing between wildlife conservation and oil development projects in Murchison Falls National Park and in the Albertine graben.