The Impala Lamb Equation – Londolozi Blog

With the lambing season of impalas behind us, and the gregarious and abundant impala herds now roaming the lush landscape around us, one can’t help but marvel in the copious numbers of this one particular species we see here at Londolozi.  

The success of this antelope – a species that is so vulnerable to predation from most carnivorous mammals – is often something that comes up in conversation while on game drive. 

Impala have a widespread distrbution across many of Africa’s savannas and wilderness areas. Usually dependent on living near water, these animals tend to have an irregular and clumped distribution, yet thrive and dominate in these chosen habitats.

As a mixed-feeding antelope, impala are adaptable to graze when the grasses are growing and browse on foliage, herbs and plants when the grasses are dry. Their ability to adjust their diet according to what is prevalent in a given geographical location is a major contributing factor to the success of their species.

However, in addition to having a flexibility of diet, another factor making them by far the most prevalent antelope species at Londolozi, and the Kruger National Park, is their breeding strategy and synchronized birthing.

Impala lambs become easy pickings for the leopards of Londolozi.

Everything one needs to know about impala lambing season is described in a previous blog, but as many may already know, impala ewes all tend to give birth within a matter of three to five weeks of one another, essentially flooding the ‘market’ with a supply of impala lambs at the end of each year.

A market equilibrium is a state in which all variable forces remain unchanged from their most natural state in the absence of external influences. A point of equilibrium represents a theoretical state of balance.

In the wilderness areas around us, this is essentially when each and every species separately thrives in its own niched way while fitting into a greater web of species that make up that environment (or ‘market’).

By impala flooding the market with supply, and being the only variable to drastically increase supply in a very short space of time, the respective demand factors (i.e. all of the carnivorous mammals preying on impala) remain largely unchanged. This means that even though impalas become incredibly vulnerable to predation and ‘easy picking’ during this time given the vulnerability of the herds with many lambs, essentially the demand from the hungry stomachs of the predators remains the same. Predators can only eat so much so often. And this is where the question lies… After the flood in supply, how many lambs in fact reach independence?

Without finding any scientific or experimental evidence-based testing, it is generally understood that around 50% of them make it to breeding age. A 50% survival rate is not a bad statistic! 

However, from many chats with my fellow guides and the Londolozi Trackers, the general feeling from witnessing many lambing seasons in this area is the belief that this statistic may in fact be even higher and sit around a 60% – 70% survival rate. 

Working as a herd, aggregating their eyesight and hearing to be aware of their surroundings for potential predators, these impalas fixate their gaze towards a leopard walking past them not too far away.

Impossible to say for sure, but for a species that has virtually remained unchanged for an estimated 5 million years, their evolutionary ingenuity is something to be admired – especially considering their daily risks of predation!