I regularly refer to alarm calls while out on drive and I realise that sometimes this reference may be falling on deaf ears. They are without doubt some of the most important, if not the most important signals we use to find large predators, but first-time visitors to Africa might not be familiar with the term.
According to the online Britannica Encyclopaedia, an alarm call (or signal) can be defined as:
“a ritualised means of communicating a danger or threat among the members of an animal group”. In simpler terms, animals or birds will release a unique vocal call in the presence of danger.
Paying attention to the sounds around us while out on safari is a massive part of tracking and finding animals. The environment is alive with sounds, and deciphering what they mean is vital. Luckily for us, the Londolozi tracking team has centuries of combined tracking experience. This means that the trackers are able to distinguish between what is, for example, a normal bird song or one that indicates that a large cat is walking past. Subtle but effective.
But why do animals alarm call? This may seem obvious at first, but when one delves deeper and looks at examples, it becomes a bit more complex.
Let’s begin by discussing monkey alarm calls:
Studies have shown that vervet monkeys have developed different alarm calls for different threats. The study’s focus was on leopard, eagles and African Rock Python – all of which actively feed upon monkeys. The fact that monkeys have different alarms for each threat is an indication that they are alerting each other that there is danger at hand and that action must be taken to avoid being eaten. Depending on what call is sounded, the monkeys would either dart for cover from eagles, stand on two legs to look out for a snake, or climb to the tops of trees to get away from a leopard. In this case, alarm calls serve to keep the troop safe and can be considered intricate communication between the monkeys. Watch this video of monkeys alarm calling to get an idea of what it sounds like. (If you hear this from your room at Londolozi, try and see which way the monkeys are looking and you could spot a leopard!)
Now if we take a look at impala, and their response to different threats, the theory behind alarming becomes quite interesting…
Impala are herd animals, typically found in large numbers, other than the exception of single impala rams that have established territories for the rutting period. Throughout the day and night, there will always be several impala scanning around for any potential predators. There is no organisation or time-share agreement here – naturally while one has its head down feeding, another will be on the lookout. If a lion, leopard or cheetah is seen by an impala, the antelope will start to make a cough-like alarming sound, while staring at the threat.
The alarm calls of impala serve two functions: i) to alert the rest of the herd to the presence of danger; and ii) to alert the predator that it has been seen. This second one is most crucial. In the case of leopard and lions, the element of surprise is the most critical factor in a hunt. If this is lost, the lion or leopard will give up on the hunt, almost every time. Therefore, the impala alarm call is not only serving to alert the rest of its own species, but is also giving vocal cues to the predator to stop hunting. Another example to back this theory can be shown through African Wild Dogs.
When wild dogs hunt, they rely less on the element of surprise but rather capitalise on mass panic of an impala herd and chase down and catch individuals that become separated off from the herd. Whenever impala see wild dog, there is no alarm calling. The impalas immediately sprint for their lives – silently – often throwing their hind legs into the air dramatically while fleeing; a display known as stotting. This is fascinating because it means each individual is concerned with saving its own life as it flees, not caring to alert the rest of the herd like they would if they saw a leopard or lion. What this tells us is that when impala alarm call – really they are communicating as much with the predator – shouting “Hey! I’ve seen you! Don’t hunt!” – as much as they are alerting fellow herd members to the potential threat.
So from the evidence we have discussed thus far, it is clear that alarm calls are not only for communicating within a species (intra-species) but also between different species (inter-species). On this same note, it is not only us on game drive that are listening out for alarm calls. A sleeping hyena or lion can awaken very quickly if it hears serious enough alarm calls close-by. We have often seen large predators get up and trot in the direction of alarm calls, in the hopes that they will find themselves a kill that they can scavenge.
A good rule to remember is that the smaller the species, the less reliable the alarm call may be. For example, a small bird will alarm at anything from a larger bird, to a mongoose, to a leopard. So sometimes they are effective in taking note of, but not nearly as effective as a large animal such as a kudu. A kudu is not concerned with a mongoose, thus when you hear one barking in alarm, there’s a good chance that a lion or leopard has been spotted. Take a look at this previous blog post that lists some of the finer details on which species’ alarm calls are useful to take note of. Hopefully now when your ranger or tracker refers to alarm calls you will know what is actually happening around you!