Monday, September 8, 2008
Posted by Kate at 12:18 PM
In order to collect some kinds of data, we have to get up close and personal with the hyenas. Since none of us are willing to lose a limb (or our lives!) to those strong jaws, we dart the animals in order to work on them. Here's the process, with some pictures from the darting that Audrey and I did this morning...
First, we identify a target hyena, which is more complicated than it sounds. The animal has to be alone, because lions and other hyenas may attack a vulnerable hyena while the drug is taking effect. We also don’t want the hyena to get lost in the bushes or fall into water before we can get to it, so we only dart in open areas where we can keep an eye on the hyena as it goes down.
If we’ve found a good darting situation, we fill a dart with a drug called Telazol and load it into our CO2 rifle. As soon as the hyena turns away from us (we don’t want it to associate our vehicles with the experience of being darted), we aim for the hindquarters and shoot. Hyenas generally start to act “drunk” quite quickly, and they’re usually down just less than ten minutes after they’re darted.
Once it’s safe to get our hands dirty, we work as quickly as possible. First, we cover its eyes because, although the animal is immobilized, it’s not unconscious; bright colors and fast movements can disturb hyenas while they’re down. Then, we draw several vials of blood to look at hormone levels, immune function, and DNA.
We take many different tooth measurements (by the way, since hyenas chew on so much bone, their teeth are surprisingly clean and their breath doesn’t stink nearly as much as you’d expect!), and several body measurements as well. This morphological data helps us understand how hyenas’ teeth, skulls, and bodies change with age. It also shows us the physical differences between males and females, and high- and low-rankers.
To identify the individual again in the future, we often ear-tag hyenas when they are darted. If this hyena is seen again (or found dead) many miles away or several years later, eartags can give us important information on movement, dispersal, and mortality.
Finally, we drive the hyena to a safe place in the bushes to wake up and cover it with water to keep it cool while the drug wears off. This can take anywhere from a few minutes to an hour or more, depending on the individual (the hyena in the picture is already raising its head and starting to come around).
While that’s the end of the actual darting, we still have work to do! We go back to camp to do all the bloodwork so that the samples can be sent back to the US. Fisi Camp may be in the middle of nowhere, but we’ve got plenty of sophisticated lab equipment (which we run off solar power and car batteries) to help us get the job done.
All in all, darting is a lengthy and complicated process, but it’s also unbelievably exhilarating to work, hands-on, with such an amazing predator.