One of my favorite places in Botswana is the Savuti Channel, located in the heart of Chobe National Park, not only because of its unpredictable water flow, but because it is an intermittent elephant refuge. I first visited the Savuti when I was eight years old, while on safari with my parents. Back then, the river sparkled, teeming with catfish, huge crocodiles, and pods of territorial hippos. The river provided cool relief for the wildlife, while the Savuti Marsh provided fields of life-giving grasses for ungulates. I was most impressed by the large herds of elephants, buffalo, zebras, and wildebeest blithely making their way through another day, while predators waited patiently, hiding among the thick shrubs along the marsh. We were camping in a safari paradise.
While at boarding school, I read that in 1982 the Savuti Channel was dry! I did not understand then that for the past 170 years, the Savuti River had an erratic, unpredictable flow. Today, the reasons that result from this unpredictable ebb and flow still remain unclear, and scientists have suggested that tectonic rather than hydrological factors may be at the root of this phenomenon. Where would the elephants go during these dry spells? Much of the wildlife moved on to “greener pastures,” and soon the area became a paradise lost. The stark pictures in magazine articles of the secretive works of nature convinced me that I needed to investigate this ancient mystery. I returned in 2001, this time for the meaningful purpose of pursuing my doctorate in elephant ecology.
Family groups of elephants were gone, only visiting the Savuti on their 100-mile treks to the Kwando River on the Namibian border. However, large elephant bulls had made the Savuti their safe haven, seeking refuge at the artificial waterholes the Botswana government had sunk into the parched landscape to provide water for wildlife. The intense smell of fresh, deep water brought up from deep below the Kalahari sand proved to be too tempting for the thirsty giants, which wandered into unsafe territories surrounding Chobe. Savuti became world renowned for its massive, old bulls, which became tolerant of pachyderm fans seeking to see these lords of the African savanna in close proximity.
Finally, in 2008, water unexpectedly began to appear in the Savuti Channel. The following year, there was much excitement and anticipation on how far the water would flow. Many people, including myself, made journeys specifically to see just how far the water would flow. By 2010, the Savuti River was a flowing river, spilling its waters onto the Savuti Marsh after a 28-year dry spell!
Fortunately for me, the timing of this flood was perfect, as I had recently secured funds and permission to conduct an aerial survey to count elephants and other large herbivores throughout northern Botswana. I was amazed to see that the Savuti had been rejuvenated. Massive numbers of elephants amassed on the marsh. Buffalo had returned after many years of absence. I realized then that my understanding of elephant ecology had to span longer than my brief five-year doctorate study. Nearly 30 years after my first camping trip in Savuti, I deployed two satellite collars on adult elephant cows and one on a bull to better reveal the movements of elephants in this dynamic environment. I might have to wait another few decades to see where they move to when the Savuti decides to dry up again. But then, at least, one of the secrets of the Savuti’s inhabitants will be revealed.
Michael Chase is the Henderson Endowed Postdoctoral Fellow for the San Diego Zoo Institute for Conservation Research and the director of Elephants Without Borders.