Huge numbers of wildebeest deaths on the Mara River

October 2007. Kenya Wildlife Service (KWS) has issued some clarification on the numbers of wildebeests swept away by raging waters of the Mara River in this year’s migration. According to KWS scientists based in the Maasai Mara National Reserve, about 5000 wildebeests drowned as they tried to cross the crocodile-infested swirling waters.

 

In fact around 3000 wildebeests drown every year while crossing the Mara River, so while this years number was larger than usual, it does not merit some of the sensationalism that has appeared in some of the press. Although unusually high, similar numbers of casualties occurred in 2005. Some people who saw the heap of about 1500-2000 carcasses were horrified by the sight but unfortunately reported seeing more than 10,000 animals, and some reports mentioned 15,000.

Crossing the Mara River
Traditionally, there are about eight favourite vantage points where the vast wildebeest herds are known to cross the Mara River. Most of this year’s deaths occurred at two crossing points that are popular with tourists, especially photographers. For reasons unknown, some of the wildebeests chose a couple of new crossing points that had steeper river banks.

 

Heavy rainfalls
The probable cause of the drowning was heavy rainfalls experienced throughout Kenya which caused the rivers to swell. Some of the floods in September have been linked to the destruction of the Mau Forest upstream in the catchment area of the Mara River.

According to Mr Patrick Omondi, the KWS Head of Species Conservation and Management, the drowning was a natural selection phenomenon in a migration of more than 1 million animals. ‘It’s part of the population dynamics in the spectacular migration and there’s nothing we could do about it. There is no rocket science to explain what happened when the animals’ self-preservation instincts failed.

Although 5,000 deaths is a heartbreaking loss, it is still a tiny fraction of the more than 1 million wildebeest in the Mara-Serengeti eco-system. It also has major benefits for the crocodiles, vultures, hyenas, jackals and all the carrion eating wildlife of the Mara.

The Great Migration
The wildebeest deaths are replenished by the over 400,000 births every year. Peak season begins in July and ends later this month when the wildebeest migrate from the Mara Savannahs in Kenya back to Serengeti National Park in Tanzania. The Kenyan government stopped all developments in the Mara and is preparing the Mara Conservation Area management plan.

The annual Great Wildebeest Migration was named as one of the New Seven Wonders of the World in November 2006 by a panel of experts in America.