Driving around at this time of the year there is a very common sound that emerges from the vehicle every time we see a herd of impala. The “Ooh”s and “Ahhh”s are always on cue; it doesn’t matter how often you’ve seen them, but an impala lamb seems to melt the heart of pretty much everyone. It’s the time of the year when most of the young impala have been born, all nearing their second month on this planet, no doubt still experiencing things for the first time.
What goes unnoticed to most observers is that the process for the next batch of youngsters to be born the following year has already started.
Photoperiodism: An organism’s reaction to the change in length of day. It’s a rather large word, photoperiodism, and always seems to take a few breaths to get out, but its a phenomenon that is very much alive out in nature, that most of us are completely unaware of.
From the 21st December (the Summer Solstice) the daylight hours in the summer hemisphere begin to shorten almost immeasurably. This may seem like a rather non-important progression in most of our lives, but for animals, plants and birds, its a pretty huge deal. Its very much evident in most organisms, I could name quite a few in the Londolozi area, but I’ve chosen to focus on the impala, as they are something we see all the time, mainly as they are our most prolific mammal.
The process starts with the male impalas. As the days begin to shorten, male impalas begin to produce a lot more testosterone than usual. This makes them a little more aggressive with each other and they begin to start practicing their rutting (fighting) skills. At first it’s very much just for show, but as the months go on and the days shorten, the fights get more and more serious and eventually in May, the rut reaches its peak. This is when there are serious battles amongst the males for the right to mate with the females. Whilst this is all happening, the females – most of whom would have been caring for their young – also react to the change in daylight hours. Their reaction isn’t directly because of the sun, but they react to the change in the males’ behaviour and increased testosterone and will slowly but surely come into oestrus again. The height of their oestrus is around the same time as the males’ rut in May, and the mating process begins. Most the females who are of age will fall pregnant, and the gestation period starts.
The wait is around 6 – 6,5 months, and then just as the first rains have fallen, around early-mid November, the females will all drop their lambs at a very similar time, and the process starts all over again and the “ooh”s and “Ahhh”s will be heard from the Land Rovers once more.
It is undoubtably impressive to see a massive male lion or a stealthy leopard, but sometimes these beautiful and more sought after animals aren’t that easy to find, so we do need to take the time to notice the smaller things and the incredible relationships that are to be found all around us. Impala are often the most overlooked inhabitants of Londolozi, but a closer examination of their lives can be fascinating.
Filed under Wildlife
Impalas are so often ignored but they are a really beautiful and elegant animal
As usual very informative and interesting, Impala are magnificent.
A fascinating read Kevin and an aspect we as humans don’t think a great deal about. Are you saying a female impala’s biology isn’t as sensitive as a male’s to changes in daylight length but rather rely on cues from the male’s behaviour? Does this mean in zoos or example where females are often segregated from males, oestrus may not occur or may be slower to occur?Also could you write about how the plant varieties at Londolozi respond to this phenomenon? Nature is truly amazing!
Great write-up Kevin! The Impalas are beautiful and so graceful and always lovely to see how caring and protective the mothers are with their lambs.
Great article Kevin. The impala really are majestic animals and, unfortunately, get brushed aside in favour of lions, leopards, etc. It always amazes me when I see newborn impala and ellies almost immediately are on their feet and following Mum. We humans are coddled when it comes to childbirth. Nature truly is amazing.
Awesome article! But I blame finding this blog for my inability to finish my paper…