Notes from the Field – Serengeti
It is now July, the dry season in the Serengeti, and the dust billows thickly in the wake of Safari jeeps laden with tourists and camping gear. It settles slowly, covering all exposed surfaces with a fine, powdery skein, clogging noses, coating hair and getting into pores. The vast short grass plains of the south-east are empty, almost entirely devoid of life, save scattered herds of Thompson’s gazelles and their stately cousins, the Grant’s, grazing determinedly on the sere grasses. This scarcity seems shocking following so soon after these same plains, then lush and green from the April and May rains, abounded with teeming herds of wildebeest and zebra, their dizzying numbers only made vaguely comprehensible by the immense extent of land which encompassed them. Then the predators on the plains fed well, their larder stocked. Now the lean season has come and life on the plains is less desirable, less certain.
Out in the western corridor, where the Serengeti National Park narrows, pinched between two rivers until it is mere kms across at its western boundary near Lake Victoria, the story is different. Here there are hills, woodlands sparse and dense and closed canopy riverine forest. Here also the plains are small - grasslands really - the grasses often long and waving (although June burning by Park officials has rendered most black and stubbled). Most importantly, however, there are resident herbivores. Although their numbers pale in comparison to those of the migrants that are now drifting in most migrants will continue to move, walking north to end the dry season in the Kenyan plains north of the mighty Mara river, before October rains start to pull them back south again toward the south eastern Serengeti Plains. The residents on the other hand, will remain, and for predators their presence throughout the year forms a buffer from potential starvation.
The story may be different in the west, but the details of that story are shrouded. That is why I am here. It is my goal to attempt to untangle one small thread of the complex tapestry, to shed some meager light onto the shadowed pages of that story (and to crudely mix metaphors, clichéd ones at that!). Why? So that it can be known. Known for the sake of knowledge, of scientific discovery and, perhaps more importantly, of future conservation and management.
Specifically, I am investigating lions and hyenas here, how they distribute themselves across space and time, what they eat and how their feeding changes in the presence and absence of the migration. These two social carnivores are the most important predators in the Serengeti system, responsible for an estimated 85% of large herbivore predation mortality. I use a combination of new technology and old field craft in my efforts to understand them, with GPS satellite collars employed to track movements and hours of sitting and watching through binoculars to quantify behaviour.
I arrived last October and spent the first two months learning the system, locating and identifying lion prides and hyena clans in a part of the park where almost nothing was known about them. Tour guides were helpful, as they spend their days looking for the charismatic big mammals in order to please their guests, and the more attentive learn to recognize individuals and even determine pride compositions. In mid-December, together with my colleagues on the Serengeti Biodiversity Programme (SPB), I organized a collaring session with veterinarians from both the Tanzanian National Park Authority (TANAPA) and the Tanzanian Wildlife Research Institute (TAWIRI). The goal was to find, safely immobilize and attach GPS collars to 5 female lions and 5 female hyenas. If that was not a daunting enough task, my study design called for the carnivores to be neighbouring and overlapping. I was thrilled to end up with 5 hyenas and 4 lions successfully collared in 5 long and exhausting days. We collared a 5th lion in February to make 10, but one hyena and one lion collar have subsequently dropped, leaving 8 currently collared animals.
I consider myself very fortunate to have this opportunity to work in such an incredible location with its profusion of fascinating wildlife. I am most grateful to TAWIRI and TANAPA for allowing me this chance, as well as the SBP and the University of Guelph where this research forms part of my PhD thesis and only hope that the information gleaned through my efforts proves useful and valuable.