Patterns of water use among African Savannah elephant (Loxodonta africana). Movements toward a water source.

Sammanfattning

The African savannah elephant requires a large amount of water to sustain itself and regularly travels to water sources, typically along traditional ‘elephant highways’ and frequently through or in close proximity to human settlements or farmland, with negative interactions and consequences for both humans and elephants. To help mitigate these problems, a better understanding is needed of spatial and temporal patterns of elephant movements to and from water sources. This study of elephants in Makgadikgadi Pans National Park, Botswana, used camera trap images to analyse when and why elephants travel towards their main water source, the Boteti River. Camera trap images taken along an elephant highway, leading down to the water, between 2014 and 2017 were used within the framework of a general additive model (GAM) to predict elephant movement across 24-hour cycles. Different factors including herd size, temperature, presence of juveniles and 30-day mean rainfall, were allowed to interact with time of day to check for their effects on the probability of elephants traveling to the water. The results showed strong interactions between time of day and herd size, as well as between time of day and temperature in changing the probability of when the elephants sought out the water source. Larger groups showed less of a diurnal pattern, which could indicate a greater sense of security or showcase the influence of between group variation in terms of ecological strategies. Higher temperatures resulted in a greater drop in probability in the afternoons, likely related to heat avoidance by the elephants.