Start of the rut

Been out on safari lately? You would have noticed a slightly chillier morning game drive and earlier sunset. The shift of our wet to dry season is starting and with it a special period commences for the impalas. This season is known as the rut. Impalas are the only African antelope that exhibit a true rut. It is caused by the shortened daylight hours. This triggers the pituitary glands of the impala rams, which will send instructions to produce luteinizing hormone (LH) and testosterone, it also triggers physical growth. The result is increased aggression and a total lack of self-maintenance. Other than the increase in size that we can see, the impala rams have also become more vocal. The strange sounding noises, that sound like they belong to a lion, are actually guttural roars, grunts and nasal snorts. They use these audio cues to intimidate rivals and attract the attention of females in breeding herds.

The rut runs from late April through to May. During this time the main aim of the adult males is to claim territory with sufficient resources and fight off any opponents. You will often see males arching their backs and displaying their horns. They can also be seen rubbing pre-orbital glands on vegetation and defecating on middens to make their presence known.

If a male succeeds in fighting off an opponent and establishing a temporary territory, females will move throughout it. Whilst a breeding herd is in a male’s territory, he will attempt to mate with every adult ewe. Males can spend anywhere from 8 to 10 days doing nothing but mating, often disregarding feeding and grooming. Other males will take advantage of a ram’s weakened state and challenge him for territory and subsequently mating rights with the females in the breeding herds. At that point a ram could struggle to retain territory, and a new male will start mating with the females. The state also makes them more vulnerable to predators.

So, don’t be alarmed at all the strange noises and hyperactive dishevelled impala rams you’ll be seeing in the bush for the next month!