After witnessing the world’s greatest wildlife migration along Kenya’s Mara River, the author reflects on the role of rivers in nurturing entire ecosystems.
This post is part of a special National Geographic news series on global water issues.
By Mark Angelo
As an avid paddler and long-time river enthusiast, I’ve always marveled at the ability of rivers to nurture life. But while we often focus on the many aquatic life–forms that inhabit rivers, our waterways are more than just linear lifelines; they’re also the foundation of entire ecosystems.
As a result, the land adjacent to rivers is a rich interface where life is more vibrant and diverse than elsewhere, providing some of the most productive natural habitats in existence. Perhaps nowhere is this more apparent than along the banks of Kenya’s famed Mara River.
Arriving in Nairobi in early August, my wife and I and our two daughters were greeted by our driver and then quickly set out for the source of the Mara, which originates in the lush mountain forests of Kenya’s Mau escarpment. After a leisurely day’s drive across the Rift Valley, we finally got our first glimpse of the river which begins as a tiny stream in its uppermost reaches but quickly increases in size as it tumbles out of the mountains.
Wildebeest near a river in Serengeti National Park.
The area encompassed by the wildebeest migration is massive in size, spanning both Kenya and Tanzania and covering most of the Serengeti-Mara ecosystem. Along with about 200,000 zebra and half a million Thomsons gazelle, the wildebeest migrate in a clockwise fashion, traveling more than 2,000 kilometers [1,250 miles] each year in search of rain-ripened grass. For these vast herds of animals, there is no beginning or end to their journey. Rather, they travel constantly in a never-ending search for food and water.
During the wetter parts of the year, the wildebeest congregate in the short grass plains of the Serengeti where about 80 percent of the females give birth to young calves. But as the dry season approaches and the food supply dwindles, they head north towards the greener pastures of the Mara.
Photo of wildebeest gathering by Mark Angelo
By July, the herds have amassed along the swollen Mara River. While some animals briefly pause here, most are instinctively driven to move on and they begin crossing the river, the final barrier to the rich grazing of the Mara plains. Sometimes the place of crossing is relatively shallow and placid, allowing most of the wildebeest to pass safely. Other times, it is not.
During my very first trip to the Mara, I was staying at a tented camp along the river when I awoke to what I thought was the sound of thunder. But, after hearing the commotion in camp, I soon realized it was the sound of thundering hooves. As I left the tent, it seemed as if the earth was vibrating beneath my feet. I scrambled up a nearby embankment and saw a large herd of wildebeest approach the river in a frenzy. They jumped down the steep bank, paused momentarily at the water’s edge, then entered the river en masse.
Wildebeest beginning to cross.
Photo by Dreamstime
Wildebeest charging into the river.
Photo by Dreamstime
Once in the river, many of the animals struggled with the fast moving water. Of those that made it across, many had trouble getting out of the river due to its steep banks. Some of these animals appeared to panic, only adding to their exhaustion.
After several minutes (although it seemed much longer), most of the wildebeest appeared to have safely crossed, although a number of animals had perished. I saw a crocodile seize one young wildebeest and several more were probably preyed upon during the chaotic crossing. Still others succumbed to the high water levels and drowned, their carcasses gathering in the eddy pools downstream where they would be fed upon for weeks by vultures and storks.
Wildebeest carcasses in eddy.
Photo by Mark Angelo
Vulture feeding on carcass.
Photo by Mark Angelo
The heart-stopping excitement of a wildebeest river-crossing is something you can never forget and, to this day, I equate that experience with the ultimate definition of wilderness in its rawest and most unforgiving sense. But while the risks, and sometimes deadly consequences, of crossing the Mara have been well documented, this should not obscure the fact that the river plays a crucial role in maintaining one of Africa’s most productive wildlife habitats.
Clearly, the story of the Mara River is more about life than death. This is especially apparent during the migration, which my family saw at its peak during our visit. Traveling in close proximity to the river, we encountered vast herds of wildebeest for days on end. At times, we were totally engulfed by them and my daughters were amazed that gold-colored grasslands could be turned black by the sheer number of animals around us.
When the herd was moving, the wildebeest traveled in long, closely packed columns but, when stopping to graze, they would spread out as far as the eye could see. As Elspeth Huxley stated in The Last Days in Eden, “they looked like great hordes of ants speckling the plain.”
Beastly River Battle: The video above of the Serengeti wildebeest crossing the Mara is a clip from “Great Migrations,” a series that premieres in the U.S. on the National Geographic Channel, Sunday, November 7, at 8 p.m. See more videos and read more about ”Great Migrations” on the National Geographic Channel website.
When it was finally time to leave the Mara River, my oldest daughter Kelly commented on how fortunate we were to have seen this amazing place; “the greatest show on Earth” where natural interrelationships continue to function on such a large scale. While I wholeheartedly agreed, I also knew that there were environmental threats on the horizon that could impact the future health of the Mara ecosystem.
For example, things like habitat fragmentation, climate change and deforestation in the river’s headwaters remain very real concerns. But also worrisome at present is the planned construction on the new “Serengeti highway” linking Musoma (on the banks of Lake Victoria) to the city of Arusha. This road will cut a swath through part of the park and construction is set to commence in 2011. Tanzanian authorities claim this will aid development in one of the most remote corners of the country. But in the view of many, this highway, which will be utilized by a minimum of 400 trucks a day, poses a threat to both the park and the migration.
Aside from its obvious potential to disturb or hinder the movement of animals, wildlife biologists fear an array of likely impacts. Among these are the high probability of vehicle-caused wildlife deaths, the possible introduction of domestic diseases, hydrological changes and the provision of easier access for poachers.
On a encouraging note though, a major internet and media campaign is now underway, led by a coalition of scientists, to try and stop the project. In a broader vein, there have been effective efforts by groups such as the African Conservation Foundation and the Mara Conservancy to foster an enhanced commitment to ecosystem sustainability. In addition, many conservationists are pushing the Tanzanian government to consider a more southerly route for the road that would be far less intrusive. Only time will tell if they’re successful.
As I reflect on my past trips to the Mara River, I believe that, at least up until now, Kenya and Tanzania have succeeded in doing what many other countries have failed at. They have protected a substantial natural ecosystem and, as a result, the great wildebeest migration remains largely in tact.
In a similar vein, I’m hoping that Canada and the United States will be just as successful in protecting the migratory range of the massive Porcupine caribou herd (so-named after a river these animals cross on the way to their calving grounds). Like the Mara, the ecosystem that sustains this migration spans two countries but has frequently been threatened by oil drilling proposals in Northern Alaska.
The Mara River, and the lush plains that it feeds, also illustrates the need to manage waterways as centerpieces of local ecosystems. In British Columbia, our rivers are amongst the finest in the world and yet, they continue to face an array of threats including pollution, resource extraction, encroaching development and questionable land-use practices. If we are to do a better job of protecting our rivers in future, we must think in broader terms than we have in past and increasingly focus on the sound management of watersheds and ecosystems.
If we can achieve this, that will not only bode well for rivers but will also mark an important starting point in our efforts to better care for the planet. Realistically, I recognize that it won’t be easy to undo the damage that has already been inflicted on many rivers. But after a magical experience along the Mara, one can’t help but be invigorated and a little more hopeful.
Mark Angelo is the chair of the Rivers Institute at the British Columbia Institute of Technology and an internationally acclaimed river conservationist. He has received the Order of Canada, his country’s highest honor, in recognition of his river conservation efforts both at home and abroad. He received the United Nations International Year of Fresh Water Science, Education and Conservation Award, the Order of British Columbia, the National River Conservation Award, and an honorary doctorate from Simon Fraser University. He is a Fellow International of the Explorers Club. Angelo is the chair and founder of World Rivers Day, an event celebrated across dozens of countries on the last Sunday of each September. He has traveled on and along close to 1,000 rivers around the world over the past 5 decades. He has authored numerous articles and papers about rivers and his expeditions, including the Riverworld presentation launched in concert with National Geographic Online in 2003 and shown to audiences across North America.
The views expressed in this article are those of Mark Angelo and not necessarily those of the National Geographic Society. Read more blog posts by Mark Angelo.
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From Chantelle F:
Mark Angelo has a fantastic and positive attitude–his passion for river conservation inspires me to drive toward my own goals for wildlife conservation.
A fantastic read and a great individual.
Keep up the great work Mark and I will continue to pass on the word of your work and the importance of conservation.
“Knowledge and education is the key to conservation.”