Sunday, 12 April 2009

Collaring Zebra in the Makgadikgadi

Hello everyone,

On April 1st I finally became a fully paid up zebra researcher as I deployed my first collars onto zebra mares within the Makgadikgadi. Darting Zebra from the ground in the Makgadikgadi had never been done before as historically the zebras were too skittish around vehicles as they used to get shot by poachers and farmers, or chased away from waterholes so that cattle could drink instead. We thought that we would give it a go though as the cost of hiring a helicopter for the exercise was extremely prohibitive.

When we found the zebra herds the wind was blowing and we weren’t sure how close we would be able to get to them. To dart accurately you need to be around 40 metres from your target animal. 40 metres is a lot closer than you realise when you don’t have a range finder with you and to get this distance from a wild animal with strong herd behaviour is difficult.

The first shot we had missed due to the effect of the wind. The second shot somehow made it and at 47 metres was a great shot as darts aren’t really supposed to go over 40 metres. Everything went smoothly with the collar fitting and the zebra was up and back with her harem less than 40 minutes from the dart hitting.

The next zebra that we darted was the matriarch of her harem and so she fought against the effects of the tranquilizer. The matriarchs do this because when they start to show a weakness, lower ranked females in the harem will try to use the opportunity to increase their rank. The problem is that it is almost impossible to tell who the matriarchs are when you are approaching a herd of zebra, any female could be a matriarch. The tranquilizers used had the desired effect and it was possible to fit the collar and take all of the necessary measurements and samples.

I had chosen, as other researchers have, to dart only adult zebra mares. This is because the stallions will often fight with each other and during these fights they bite and hold the neck of their opponent. If we fitted a collar to a stallion there is a risk that the collar would be damaged during fighting, and, perhaps more importantly, it may provide an advantage for an opponent as they have something else to grab hold of when they bite.

When a zebra mare is darted and goes down the remainder of her harem will remain close by as they are a very close unit. They will retreat to the safety of the herd and watch from a safe distance, around 200 metres, but they are always alert and waiting for the mare to return to them. As soon as she is back on her feet and heading towards the herd, the harem will come out to greet her to make sure that all is ok before they all return to grazing.

During the following three days we were able to dart a further 7 zebra by using a great deal of patience combined with the experience gained during each previous darting. One of the hardest things is to be patient when you can see 2000 zebra but you can’t get close enough to dart. You need to have a great deal of patience to keep looking for an opportunity to get close to the herd.

On the third morning we needed to be patient once we had found a number of big zebra herds. Unfortunately all of these zebra were heading into drink at a nearby waterhole and so were already on edge. This is because predators often reside near to waterholes as they know that their prey will need to come and drink. We tried to target herds which had already drunk from the waterhole and so were walking back out to graze. It was still proving difficult as the herds were still on edge until they got far enough away from the waterhole.

We ultimately managed to get close enough to a herd to identify a zebra mare to be darted. Everything then went smoothly as the zebra went down nicely and allowed us to fit the collar and take measurements. This zebra is the only zebra which has so far been named as I am going to let the children of Khumaga Primary School name the remainder. I named her Mosetsana (pronounced: mo-seet-sana) which means ‘Little Girl’ in Setswana. This is because she was young, around 4 years old but with a 6 month old foal, and was the smallest zebra which we darted.

The collars which we are using are Satellite GPS collars which send me emails with the GPS locations of each collared zebra at specified times. These collars are all working well and are already sending me data which shows their movement patterns. I will hopefully have a link on the website set up very shortly which will allow you all to see the movement patterns of three collared zebra. When this is done I will let you know and explain what it all means.

I will also place some pictures of the darting process onto the website gallery. You will see that we blindfold the zebra when we have darted them. This prevents the zebra being overly stimulated by light and movement while it is tranquilized. At all times we make every effort to have the zebra back with their harem as quickly as possible.

I hope that this gives you an insight into the collaring process and the challenges that are faced. Over the next 7 months or so I will be receiving regular updates and collecting detailed movement data for the collared zebra which will help us to understand how the fence has affected their movement patterns and resource use. If you have any questions about the collaring process or how the collars work and the information that they provide then please feel free to contact me and ask me anything.

Till next time,


No comments:

Post a Comment