Chad Cocking, a much loved ranger and wild life photographer at Tanda Tula, recently took some incredible images of Impala during their 'rutting season' at Tanda Tula. Here follows some myths and truths on these fascinating creatures, going through the circle of life as published on their blog.
“Shhhhhh! What is that sound?” is a commonly heard line at Tanda Tula Safari Camp, this time of year. This question is usually quickly followed by a dimming down of talking. As all the guests strain their ears to hear what their travel companions heard. Suddenly, a vicious, guttural roar comes emanating from the nearby bushes. All eyes open as wide as saucers as someone states: “It’s a lion!”.
As guides, we swiftly calm the situation down. Everyone’s eyes return to more normal proportions. We inform them that the roaring sounds they are hearing are nothing more than hormone-driven male impalas. They are making their masculine-presence known to the entire impala world. Despite their appearance, these quiet-looking bovines can put on quite a raucous, anything-but-antelope-sounding, display when they need to impress the ladies.
May is the middle of the impala rutting season. It is a unique time of year to watch these often overlooked antelopes, in the throes of the busiest part of their annual social calendar. Usually peaceful and calm, the rising hormone-levels in the impala males evoke a level of behaviour not shared by any other male antelopes in the Timbavati, and so it is very interesting to view these antelopes.
Difficult to miss
Impalas are the most abundant and widespread of all the antelope species in the Kruger National Park and have become a common sight along most game viewing routes. After only a short time, most visitors to embark on a game reserve, stop paying too much attention to these herbivores. If they were less common, I am sure they would draw a great deal of attention. They are, without a doubt, the most interesting of the antelope species in the Greater Kruger.
They are one of the few indigenous mammal species to have increased in numbers and range over the last century. This can be attributed to a number of factors. Their generalist approach to food allows them to both graze (eat grass) and browse (eat leaves), hence their tolerance to a variety of habitats. They also have constant access to water as there are many permanent waterholes across the Kruger.
Birth and motherhood
Lastly, their synchronised births in a three to four week period at the start of summer, flooding of the bush veld with lots of impala lambs. Consequently, even though the predators are going to eat more than their fair share of lambs during this time, there are so many around that it is impossible to eat them all. A good number will survive this most vulnerable period of their lives and will successfully make it through to adulthood.
The myth has always been that impalas can wait out giving birthing until the first rains. As a result, we tend to only see baby impalas after the first summer rains. Sadly though, this is nothing but a myth and after six and a half months, the impala lambs are ready to be born with no turning back and telling it to wait for the rain!
An other important factor that plays a role in the peaks of the annual lambing season depends on the ever so important part of the breeding process... and that is when the lamb was concieved!
With the approach of autumn, days grow shorter and the diminishing of light reaching the pineal body in the impalas’ brains initiates the release of hormones, including androgen and testosterone. This all contributes to the ram’s changing behaviour. The males start running around, chasing one another as well as the females and roaring the days and nights away. This physical demonstration of the hormonal changes taking place inside of the rams actually becomes the physiological trigger that causes the females to synchronise their oestrus cycles. In other words, it is the boys behaving badly that brings the females into oestrus at the same time!
So, just how badly are these boys behaving? Considering that for the most part, it is only the territorial males that get an opportunity to mate, they are prepared to put life and limb on the line. They will stop at nothing to establish themselves as territory holders. Guided by hormones, they will do their damnedest to keep all the other challenging males out of potential territory. Most importantly, keep the females within the confines of his small area for mating!
The pressure for territories is extremely high. As a result, even the strongest males will only hold onto a territory for a week or so before losing out to a fitter bachelor that has been waiting on the side lines for a chance.
The territorial males will approach any male that enters his territory. He will attempt to deter them with displays of dominance. If that fails, they will physically engage in a tussle with their heavily ridged, rapier-sharp, lyre-shaped horns.
When tussling, the intention is no doubt to cause injury to their opponent and stab them with their horns. Despite the apparent ferocity of these engagements, very few fatalities result from these fights. This is possibly as a result of the thicker skin that male impalas have in the neck and shoulder region. Should the territorial male lose out to a newcomer, he will once again fall into the pool of bachelors hanging around on the outskirts of the other males’ territories.
Here, he will be less active and spend time feeding well. He'll practice his fighting and build up his strength to hopefully challenge once again. He will aim to challenge for his territory before the end of the mating season. The new male that has taken control over the territory will now have his days filled with running around chasing other bachelors out of the area. He'll be fighting off challengers, and trying his best to keep the females within the confines of his territory until he too is worn out by this vicious cycle of hormone-driven behaviour. However, for the chance to mate and spread one’s genes, it's all worth it!
To help keep the females within his territory, a ram will constantly chase them deeper into his enclave. He also employs some trickery when the determined females appear to be making their way into his neighbour’s patch of land. The dominant ram will pause and stare intently into the adjacent territory and begin alarm-calling. They usually do this as a warning, as if he's just seen a predator. He does this in the hope that this will dissuade them from walking into the danger. Danger that is not actually there!
Now the excitement not only comes in the form of watching the male impalas going through all of these antics. It's also with the associated increase in predation on male impalas at this time of year. One of the challenges for a hunting leopard is finding a prey to stalk, but with the male impalas running around advertising their presence so frivolously. It makes the predator’s job much easier. Combined with the fact that the impala rams' minds are focused almost entirely on one thing, it leads to a marked increase in male impalas falling prey to leopards. This is a sight that tends to please even the most experienced safari goers!
So, next time you are on safari in April or May and you hear a roar coming out of the bushes nearby, don’t panic just yet. Chances are that's simply an impala looking for love!