When is wildebeest migration 2017

But the Mara wildebeest differ from the Pacific salmon in two important ways. The first is quantitative: they provide four times as much flesh by weight. The second is qualitative. It would be interesting to investigate what might happen should this influx of wildebeest nutrients not occur for a period of time.

With climate change, how might the frequency of these events change in the future? Has the frequency of these events already changed? Subalusky certainly thinks so. Take the American bison. Today, there are around 30, individuals left in the wild. But before the s, there were at least a thousand times as many—between 30 and 60 million of them. And that, Subalusky says, should force us to reconsider our view of what those ecosystems ought to look like.

Skip to content Site Navigation The Atlantic. Similar mass drownings may have played an important role in rivers throughout the world when large migratory herds were more common features of the landscape. Keywords: Serengeti wildebeest; animal migration; mass drowning; nutrient cycling; stable isotope. Publication types Research Support, Non-U. But one of the most serious—and overlooked—threats of this overland migration is drowning.

With thousands crossing the Mara River at the same time, scores of the antelopes are swept away by the current. Read how wildebeest know when to migrate. So for the first time, scientists have estimated how many wildebeest actually die each year: An average of 6,, equivalent to the mass of 10 blue whales.

Not only that, Amanda Subalusky , a postdoctoral researcher in aquatic ecology at the Cary Institute of Ecosystem Studies in New York, and colleagues revealed these decaying bodies provide vital nutrients to Serengeti waterways.

Learn more about great animal migrations in National Geographic magazine. Figuring out how over two million pounds of rotting wildebeest contributes to the river ecosystem is no easy feat. For the study, Subalusky and her team hauled drowned animals out of the water to dissect them and figure out their exact nutrient composition. They also put parts of the wildebeest in the river, protected by special croc-proof decomposition cages, to see how long it took each part—skin, flesh, and bones—to decay in the environment.

Chemical measurements of local water and fish were taken to see how much the nutrients of the wildebeest were incorporated into the environment. The team discovered only a small portion of the bodies are gobbled up by crocodiles—they can only eat so much, Subalusky explains. See 14 incredible pictures of African predators in action. The drowned wildebeests' major contribution to the ecosystem is their skeletons.

Wildebeest bones take around seven years to decay, slowly releasing phosphorous, an element critical for plant and animal growth. The carcasses produce maggots that feed small animals such as mongooses. Bones decompose over years and provide a key source of phosphorus in the river, which in turn supports algae, insects, and fish after carcasses have decomposed.

The nutrients are transported downstream in the river or transported inland by scavengers, helping support life throughout the entire river basin.

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