This is a tricky one.
I was reading a post about communication between different herbivores, and it briefly touched upon the possibility of animals responding to the alarm calls of others, eg. a wildebeest reacting to the snorts of nearby impalas.
Now I’ll fully admit that on game drive when seeing herbivores alarm, I’ve regularly told guests that the alarm calls will put everything else in the area on the alert, but when I consider it now, I’m forced to disagree with myself to a certain extent. I can recall multiple occasions in which the frantic vocalisations of an impala herd haven’t even aroused a passing interest in nearby kudus, and nyalas have sauntered on their way despite the squealing of a warthog that has been taken down by a leopard.
In the bush, there’s usually far more to it than meets the eye…
There’s always a reason why animals do things. To conserve energy, to gain energy, to survive… wildlife never really gets off the bottom rung of Maslow’s hierarchy of needs, and all of their actions are based upon this. Well, almost all. The thing is that from pure observation, it’s very difficult for us to tell exactly what combination of factors are at play in an animal’s decision making process.
Sure, when a lion leaves its kill to walk towards water, it’s thirsty, and when an elephant sprays mud on itself or goes swimming, it’s probably trying to cool down, but the interconnectedness of species goes deeper than surface level.
“Competition” is a very important word in the wild. It’s not only predators that compete, but herbivores too, despite their outwardly benign appearances. An open clearing might be full to the brim with impalas, zebras, wildebeest and warthogs, but just because they aren’t chasing each other round with horns flying, doesn’t mean there isn’t an undercurrent of competition.
Fortunately at Londolozi – especially now after the excellent rains we’ve experienced – resources are fairly plentiful, so competition is therefore reduced. What has been found by a research team at the University of California, Davis, is that a lot of the attention that species pay to each other is determined by population densities, which are directly related to competition.
Postdoctoral researcher Mike Gil at UCD says that at low population densities, the intercommunication between species is much stronger; animals use the interspecies “network” to keep safe, responding to the cues of others. However, when populations increase, it is the interspecies competition that has a greater influence, and animals tend to ignore each other more. The article I read wasn’t clear on why at higher population densities animals pay less attention to other species, but I imagine it is likely to do that they have more conspecifics to refer to. When there aren’t many of you around in the first place, you need all the help you can get, so take note of all environmental cues to keep safe. Also, the fewer of you there are, the higher the odds of you being on the menu, so pay attention!
Our fortunate reality at Londolozi (unfortunate for the herbivores) is that the predator density is very high. Barely an hour goes by without some indicator of a leopard or lion in the vicinity; the distant bark of a bushbuck, the chatter of monkeys, or even the call of the predator itself. I think as a herbivore out here, you have to have an innate fatalism about you. It is only the absolute immediate threats to which you can afford to pay attention, else your energy is going to be constantly poured into anxiety and stress; energy that you might need use to run for your life.
Population densities in the wild and their awareness of each other is probably mirrored by in a comparison between farming communities and cities in human populations. In a farming community, if you see smoke on a neighbour’s property (which might be kilometres away), you respond quickly. In the city you don’t; you’ll need a fire to be at the very least in your street before you pay proper attention to it. It’s almost like everyone (people) or everything (animals) else acts like a buffer between you and the danger.
I don’t know if I’m making much sense here, but the take-home message – as it always seems to be in the bush – is that things are situational. No two scenarios are the same, and to our ignorant human eyes, there is almost going to be far more at play – and therefore at stake – than we imagine.
Do different species “talk” to each other. Yes, but the others aren’t always listening…