July 8, 2009

In camp

Professor of Paleoanthropology at Lehman College and Research Associate in Paleontology at the American Museum of Natural History

RUSINGA ISLAND, Kenya | Phew! After a few days in Nairobi and a very long drive west, we’ve finally arrived at our camp. An advance team had already driven out to set up camp and make arrangements with the local authorities. Preparing for our arrival, they worked on preliminary mapping and geology for our expedition.

As you can imagine, it’s always a bit chaotic the days before going out on a major field expedition. We spent our time in Nairobi running around town gathering supplies, getting permits signed, picking up vehicles. We’re a very big crew this year–nineteen in all, meaning camp will be pretty lively! It also means nineteen mouths to feed, so I decided to hire an extra cook. Many expeditions cook for themselves, but work is scarce over here and employing local people is a way of giving something back.

It’s always fun in Nairobi at this time of year. The city acts as a sort of base camp for all of the summer expeditions hunting for fossils and artifacts in different parts of the country, from the deserts in the north to the Great Rift Valley to Lake Victoria out west. Teams are endlessly coming in and out, and we’re always bumping into old friends – swapping stories, comparing notes or showing off the latest finds. There’s a very distinct camaraderie that comes from the common knowledge of what it’s like in the field. Most of our field crew, meanwhile, spent the last few days in Nairobi going through the extensive paleontology collections in the Kenya National Museum. We have a wealth of finds from previous years that still need to be catalogued, and it’s also a great way to get one’s eye in before going out to look for new specimens.

Now we’re where we want to be. Our camp is beautiful—right on the shores of Lake Victoria. I’m looking out right now (it’s late at night) and there are hundreds of tiny lights on the lake. It’s the fisherman out at night trying to attract fish with lamps in huge wicker baskets.

After a day of organizing camp, procuring provisions and catching up with what our advance team was working on, we started fossil collecting in earnest two days ago. We’re doing things rather differently this year to help explore how fossils are getting preserved and why. In the past we’ve simply visited different fossil-bearing localities and picked up specimens that are easily identifiable – like a tooth or the end of a limb bone. We would walk all day and just collect, taking notes on where the specimen was found and which geological layer it was in. That was about it.

This year we’re doing things with much greater precision. We’ve brought out a sophisticated piece of equipment that does something called differential GPS. It tells you the exact geographical position of every single piece of fossilized bone you find on the ground. We’re taking the coordinates of everything we find, whether decent or scrappy. The idea behind this is that we can then build up a more accurate picture of how the site was formed, and which particular remains are found in each geological layer. This will help us understand if there is any bias on what is getting preserved well and what is not.
Ultimately it will help us more accurately reconstruct the ancient animal and plant communities back then, and from that we can get a better understanding of the environment these early apes lived in.

We’re also doing some proper, old fashioned excavations. This means digging a series of meter-square pits in different places which we think are rich in fossils. Surface finds are all very well, but where they are on the surface and where they came from in the ground isn’t always the same place. Finding remains in the earth is always more useful, as you
know exactly where it came from.

We’re also excavating in a number of test-pits, which is going very well. We’ve found some exquisite remains of both large and small mammals, including some primates.