Ecology from the air

Technology can change our understanding of nature.

Take for example the case of lions. For centuries, it's been said that female lions do all of the hunting out in the open savanna, and male lions do nothing until it's time for dinner. You've heard this too, I can tell. Well recently, I led an airborne mapping campaign in the Kruger National Park in South Africa. Our colleagues put GPS tracking collars on male and female lions, and we mapped their hunting behavior from the air. The lower left shows a lion sizing up a herd of impala for a kill, and the right shows what I call the lion viewshed. That's how far the lion can see in all directions until his or her view is obstructed by vegetation. And what we found is that male lions are not the lazy hunters we thought them to be. They just use a different strategy. Whereas the female lions hunt out in the open savanna over long distances, usually during the day, male lions use an ambush strategy in dense vegetation, and often at night. This video shows the actual hunting viewsheds of male lions on the left and females on the right. Red and darker colors show more dense vegetation, and the white are wide open spaces. And this is the viewshed right literally at the eye level of hunting male and female lions. All of a sudden, you get a very clear understanding of the very spooky conditions under which male lions do their hunting.

I bring up this example to begin, because it emphasizes how little
we know about nature. There's been a huge amount of work done so far to try to slow down our losses of tropical forests, and we are losing our forests at a rapid rate, as shown in red on the slide. I find it ironic that we're doing so much, yet these areas are fairly unknown to science. So how can we save what we don't understand?

Now I'm a global ecologist and an Earth explorer with a background in physics and chemistry and biology and a lot of other boring subjects, but above all, I'm obsessed with what we don't know about our planet. So I created this, the Carnegie Airborne Observatory, or CAO. It may look like a plane with a fancy paint job, but I packed it with over 1,000 kilos of high-tech sensors, computers, and a very motivated staff of Earth scientists and pilots. Two of our instruments are very unique: one is called an imaging spectrometer that can actually measure the chemical composition of plants as we fly over them. Another one is a set of lasers, very high-powered lasers, that fire out of the bottom of the plane, sweeping across the ecosystem and measuring it at nearly 500,000 times per second in high-resolution 3D. Here's an image of the Golden Gate Bridge in San Francisco, not far from where I live. Although we flew straight over this bridge, we imaged it in 3D, captured its color in just a few seconds. But the real power of the CAO is its ability to capture the actual building blocks of ecosystems. This is a small town in the Amazon, imaged with the CAO. We can slice through our data and see, for example, the 3D structure of the vegetation and the buildings, or we can use the chemical information to actually figure out how fast the plants are growing as we fly over them. The hottest pinks are the fastest-growing plants. And we can see biodiversity in ways that you never could have imagined. This is what a rainforest might look like as you fly over it in a hot air balloon. This is how we see a rainforest, in kaleidoscopic color that tells us that there are many species living with one another.