Huge, Rare Vultures Make Impressive Flying Journeys

Soaring Rüppell's vulture. Photo by M. Virani

Traveling 125 miles (200 km) under your own power might take a human a week a more to complete. For an endangered Rüppell’s Vulture with a wingspan of roughly 8 feet (2.5 meters), it’s a mere day trip.

Rüppell’s vultures rise up on thermals of hot air and can easily travel 125 miles in a day. (Photo by Munir Virani)

Long Way to Go for a Meal

Carcasses are the major source of food for large vultures. Across Africa, the distribution and availability of carcasses changes from week to week and from year to year. For a vulture, where you dined yesterday is unlikely to be where you’ll dine next week.

Cattle, antelopes, and other large mammals that make up the bulk of vultures’ diet die or are killed in unpredictable places and at less than predictable times. Often small protected areas with few predators and prey cannot provide the food needed to sustain a 15-pound (7-kg) bird. Therefore, to survive only by feeding on carrion, as most species of vultures do, you need to be able to traverse large areas on a near daily basis to find food.

So vultures are constantly on the move.

Keeping Up With the Rüppell’s

We recently tracked three Rüppell’s Vultures in northern Kenya. Their daily and seasonal movements would make even the most extreme fitness fanatics look like couch potatoes.

Using solar tracking devices attached via harness to the vulture’s back, we discovered that one young bird ranged 67,000 square miles (175,000 square km) over ten months. That’s roughly the size of the state of Oklahoma or the country of Cambodia—an area that is nearly 300 times larger than the home range of an elephant.

It was not unusual for this bird to be in central Kenya one day and then along the Ethiopian border a day or two later, —> Read More