When pressed as to why they love their job so much, most rangers will answer with, “Because no two days are the same.” This is very true because in our line of work there are many different variables that, in different combinations, produce a whole host of interesting experiences on a daily basis. Sightings, guests on your vehicle, weather, areas of the reserve, seasons, lodges; all add to this diversity and keep us coming back in order to experience more of the unknown.
One of these unpredicted and totally unforeseen encounters occured recently whilst we were following the Ntsevu Pride patrolling their territory one morning. After reacting to impala alarm calls we had found the pride walking across some open crests, clearly on the hunt. We had followed them for the better part of an hour before something else got our attention which caused us to forget about the lions very quickly.
For anyone who has spent time at Londolozi you will know that large herds of impalas are not an unusual sight. So as we slowly drove through this particular herd, waiting for the lions to reappear, we noticed that one particular impala had very strange looking horns. We stopped the Land Rover and picked up our binoculars to get a closer look. The growth of the horns started out the same as you would usually see them on a male but then when they got towards the end of the horns they became unusually thin and did not smoothen out in the same direction.
At first we thought this male might have had a birth defect until tracker Rich Mthabine turned around and, with a very confused look on his face, announced that we were looking at a female. I immediately thought Rich was looking at something else and pointed out that we were looking at the “male” with the weird horns. He nodded enthusiastically and told me to look between the legs which would be the second way of determining the sex of a Impala, the first being to look for the presence of horns.
I shifted my binoculars from the horns and employed this secondary technique of gender identification and to my utter amazement I noticed that this “male” who had horns lacked any of the other male attributes that one would usually see between the legs. We seemed to be looking at a female with horns!
We were all left quite amazed at this unusual sighting as none of us on the car had ever seen anything quite like that before. She seemed to be interacting with the herd of impala no differently than any of the other females and we didn’t notice any unusual behaviour. After chatting to some of the other rangers and a few other people who have had a lot of experience on safari I found out that it is not an unheard of sighting and a few of them had witnessed other impalas sharing the same traits as this one.
We have had some sightings in the past of a fully grown male Nyala exhibiting female colouration which some have suspected may due to a recessive gene but I couldn’t find too much information on this interesting phenomenon that we witnessed, so unfortunately I do not have a definitive answer for you as to why this female has horns. My guess would be that it probably has something to do with a hormonal imbalance and possibly an excess amount of testosterone in the female.
I would be very interested to hear if anyone else has seen something similar before? And if anyone has any idea on the genetics behind why something like this may happen?