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March 12, 2006

It's A Predator Party!

When I visited Kruger National Park, my South African friends told me that Satara Restcamp was the predator camp. Located in the center of the park, it's where you go to see the lions, leopards, hyena and cheetah. And see them, we did. In our game drives, we saw several kills, at least five different groups of lions, and two spotted hyena dens.

And it got me thinking, what kind of animal density would give the spot such a good animal-sighting record. Are there other hotspots as well? I went about trying to find out about lion population densities on the web, and it was not particularly easy. So let's look at the numbers I found, shall we?

Lion Densities In African Parks

The densities usually just include adults and sub-adults, not cubs (the Uganda report seemed to contain both). This is likely due to the fact that it's hard enough to count lions laying in the shade. Most are counted in sightings of them on the move, hunting, etc. Some do aerial surveys or counts from the ground, but lions are especially difficult to count this way, as are most noctural predators. One study even counted the lion roars in order to determine the population. Here's an example of a lion survey Serengeti Lion Survey.

As an apex predator, one of the major factors in lion population density is the density of their prey. Some researchers have found A Common Rule for the Scaling of Carnivore Density, showing that it takes about 111x as much prey (by weight) to support a given weight of carnivore. Not that the carnivore eats that much, but to scale and support predator-prey populations in an ecosystem.

From what I can tell, low African lion density is about 1-6 lions per 100 square km, medium density is about 7-14, and high lion density runs from around 15-30 lions per 100 square km. There are some great density maps toward the bottom of this report on Estimating The Global Abundance of Top Predators: The Lion In Africa.

In comparison, the mountain lions of the US range from like 0.26-0.59 per 100 km2 in Big Bend Ranch State Park in Texas to upwards of 10 per 100 square miles in the prime mountain lion habitats in California.

You can read more about the African Lion in my special assignment entitled African Field Notes: The Lion.

Posted by sorsha at March 12, 2006 10:11 PM