Activity budget and foraging patterns of Nubian giraffe (Giraffa camelopardalis camelopardalis) in Lake Nakuru National Park, Kenya

The activity budget of giraffe in various African populations has been studied extensively, revealing that it is affected by body size, foraging patterns, and sex. Foraging patterns show an animal's feeding choices in its environment and are influenced by resource availability, competition, and predation risk. The ability of giraffe to survive and reproduce is significantly impacted by the variation in activity budget and foraging across different ecosystems. Our study focused on evaluating the seasonal activity budgets and foraging patterns of Nubian giraffe in Lake Nakuru National Park, Kenya. We used the scan sampling method to record the activity budget of giraffe which included foraging, movement, resting, and drinking water. We then evaluated if activities varied with the seasons. A total of 11,280 activities were documented, with 4560 (40.4%) occurring during the dry season and 6720 (59.6%) during the wet season. Foraging accounted for 53% of the time budget during the dry season, but increased to 57% during the wet season. There was a slight drop in records of movement (22%; n= 995 of 4560) and resting (25%; n= 1145 of 4560) from the dry season to the wet season (20%; n= 1375 out of 6720 and 22%; n= 1515 of 6720). During the dry season, females (53%) foraged longer than males (47%), whereas males (44%) had longer resting periods than females (56%).

Giraffe frequently fed on Vachellia xanthophloea (67%; n= 4136 of 6215 foraging records), Maytenus senegalensis (19%), and Solanum incanum (9%) over both seasons. Overall, seasons had little impact on giraffe activity time budgets and foraging patterns in Lake Nakuru National Park. A better insight into the behavioural patterns of this subspecies will allow managers to enhance the protection and conservation of the species and its habitat. Heavy foraging on Vachellia by giraffe at LNNP has been associated with a population decline in number, so perhaps planting more of this species in LNNP could promote a rebound in numbers.

Key words :  activity time budget, forage selection, Giraffa camelopardalis, Kenya, Lake Nakuru National Park, Nubian giraffe