Gabon Update: Elephants Through Night Vision GlassesBy Liz Rowland October 18, 2010
Biologists Peter Wrege and Liz Rowland, of our Elephant Listening Project, are spending night after night on a tree platform in the rainforest of Gabon. They’re learning about forest elephants, and their night-vision binoculars are a key piece of equipment. Here’s Liz with a first-hand description:
A change of plan
As so often happens with field research, things haven’t gone quite according to plan. After six 24-hr sessions of watching the bai (clearing), we had yet to see a single elephant in the daytime, despite seeing plenty at night. This is unusual—perhaps due to late September rains, we’ve speculated. But we decided that if the elephants aren’t coming during the day, neither are we!
We’ll make better use of our time by cutting out the daytime watches and doubling the number of night watches. It’s been a good decision. It’s quite amazing to watch elephants with an infrared light and night-vision binoculars. When there’s no moonlight, you can’t see a thing in the bai. But then you look through the binoculars and miraculously, there are the elephants in greenish monochrome, their eyes reflecting brightly back at us.
Sometimes they arrive almost silently. One night, I heard just a very faint rustle and looked down to see a huge male, slowly but steadily making his way to the pond. For such huge animals, they can be surprisingly delicate. Sometimes they stand in the pond and gently feel the surface of the water—I’ve no idea why. Once I saw an adult female do this and her youngster mimicked her exactly!
The nighttime elephant activity seems to follow a pattern. Elephants trickle in just after darkness has fallen. Numbers peak between about 10 PM and 1 AM. After about 2:30 AM, we hardly ever see an elephant—that’s when it’s most difficult for us to stay awake. They arrive either as solitary adult males, or in family groups—adult females and 2–8 dependent offspring. A few are quite easy to identify, so we know that sometimes elephants come and go a few times during the night. But, mostly we can’t distinguish them, so it’s impossible to know how many individuals we’ve seen. We’ve counted a huge variation in the number of elephant-entries into the bai per night—from 2 to 67.
Male elephants can be aggressive, but often they’re content to drink side-by-side, after first figuring out who’s who. But last night, we had a large male in the reproductive state known as musth, when they tend to be dominant over all non-musth males. This one didn’t seem to mind the presence of two smaller adult males in the pond with him, but he was intent on driving off another large male. He’d head him off whenever the other approached the pond. This went on for at least half an hour.
Finally, the non-musth male came too close and the aggressive male apparently chased him off into the bushes. There followed a huge crashing of trees—it sounded like he was just venting his anger by pulling the trees down. Moral of the tale – don’t annoy a musth male.
At quieter moments, the elephants seem to be always on the alert, and often turn to face us with their trunks up in periscope position, sniffing the air, ears wide. Quite a sight when eight or so are staring at you! I swear I saw one almost stand on tip-toes he was so intent on getting a good whiff. If something scares them, they can turn on a dime and be gone before you know it.
We also see other eyes shining in the infrared light: small crocodiles silently glide across the pond, chevrotain (small antelope) delicately pick their way around the edges – picking for seeds in the elephant dung, lizards crawling up and down tree trunks, and once we saw a couple of African buffalo.
Read more about the trip:
- Elephants Visit Round Robin
- Field Report: Sounds of Gabon—and a Few Sights
- Gabon Update: Elephants Enter the Bai
- Gabon Update: 104 seconds with elephants
(Images by Liz Rowland)
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