An antelope found in abundance. Appreciated and then overlooked. Guests and rangers alike are to blame. Its success is blatantly obvious – the numbers speak for themselves and make the impala the most prevalent antelope in the Lowveld. This success is largely due to an intense couple of weeks of mating that occur. This time is known as the rut, a time of copulation but also predation.
The word rut originates from meaning to roar which this male impala is doing with his head tilted back and exhaling loudly
The Trigger: The Sun Sets, the Rut Begins
During this annual rut, the usually monotonous antelope becomes the centre of attention. Male impalas start gearing up for the rut as early as March, with the first roars breaking the air as the days shorten towards the end of summer. The shortening of daylight hours triggers changes in the pituitary gland, leading to an increase in testosterone production in male impalas and signalling the onset of the rutting season.
They mark their territories by rubbing their foreheads on small bushes and depositing scent from sebaceous glands found at the base of their horns. These territorial markings, along with middens, serve as declarations of temporary ownership that males fiercely defend.
A Symphony of Clashing Horns
While impala males typically posture to avoid physical confrontation and the risk of injury during territorial disputes, clashes are not uncommon. We often see impala rams squaring up and will hear the clash of horns. Predation on male impalas peaks during rutting season, with the large majority of impala kills observed during this time being males. Males invest up to 25% of their time herding females towards the centre of their territory to prevent them from straying to other males, sacrificing precious time that could otherwise be spent maintaining their physical condition and vigilance against predators.
Two male impalas fighting for dominance over females. During the rutting period, predators will take advantage of the more ‘oblivious’ male impala.
Nature’s Opportunists
I often explain to guests that predators are ultimate opportunists. They are trying to expend as little energy as possible to gain as much in return. Leopards will lie in ambush close to rutting impala rams waiting for them to run in their direction without paying attention to the potential threats that lurk around each corner. However, it’s not just the big cats that take advantage of this lapse in impala vigilance. African wild dogs seemingly time their denning period to coincide with the rut, preying on weaker and more vulnerable impalas that have diverted their energy towards other aspects of life.
The Nkoveni female expertly waited in ambush before bringing down this impala ram.
The Closing Act
The roars and clashes of impala males become a constant soundtrack during rutting season, but this chaotic period will eventually end. As the predation slows and the chaos subsides, much remains to unfold before the rut concludes. We try not wish away this time of activity prematurely; for a brief period, the impala will continue to hold centre stage in the wilderness.
Life in the bush is so dynamic that time can almost stand still for a brief period. Which always fives opportunity to someone else. Thanks for the continuing education Barry.
That should read allows opportunity.
We are staying on a nature reserve and we hear the impala’s rutting, fighting with the other ram’s for mating rights. Right through the day and night they are making those noises and fighting with each other. Soon there will be many little lambs running around the reserve.
This is definitely a symphony I’d love to hear! Brutality here is more or less equal when it happens, but the gradual signals they convey and display to each other often avoids the worse, unless one of the two is very stubborn even if weaker or some accidents happens (broken horns and so on). I’ve always loved impala and I’m grateful to the researchers that follow those beautiful and elegant animals. Thank you, the pictures are superb
Thanks for this information regarding impala rutting season and its relationship to predation by leopards and the correlation with African Wild Dog denning season. So cool how things that seem random on a case by case basis are connected when looked at with a broader lens!
Hi Barry, thanks for this interesting article on impalas and their rutting season.
I love Impalas. They are so beautiful. However, as they are so numerous, one does overlook them often, indeed.
I am looking forward to seeing them quite soon, September, only three and a half months away.
And guess who should be my guide and tracker? You, please and Tshepo. Very important.
Thanks Barry for enlightening us to the various facts of Impala rutting season. That and lambing season are probably the most intriguing and exciting moments to spend time with these antelopes. I’m not sure how old the males are when they begin their “practice” ruts, but it seems by the time they’re fully mature, they either have a harem or are fighting to take over one, and if not successful, continue living with the bachelor herd. It is exciting to hear to the clash of horns
during a drive , only to round the corner and find two powerful, mature rams butting heads.
Thank you, Barry, for informing us about the etymology of the word rut. Since humans don’t have a season for this, it gives a whole new meaning to being “stuck in a rut”. Also, I had to look up the word midden. I had no idea of what you were expressing until I’d looked it up. So, it’s been a very informative lesson. On top of those things, I was thinking that the survival rates of females during this period might be what makes the numbers of impala so great. But, overall, I keep to the thought that the numbers of impala are greatest to ensure that predators will always have enough to eat, even when it might be tough to find the animals – like in the dry seasons.