For years naturalists have written about the behavior of elephants without realizing they were contributing to the beginnings of a foundation of knowledge about their displays. Many of these are part of popular language. For instance, people talk about an angry elephant "charging", "flapping its ears", "kicking up dust" or "tossing its trunk." In the course of their research elephant ethologists, too, have written about specific displays using words such as "the musth walk", "standing-tall", "distant frontal attitude" or "trunk curling," to name but a few. Until recently, however, no one had tried to systematically describe the displays, signals and gestures of elephants.
Everything we and others know
In 1991 Phil Kahl and Billie Armstrong set of to Zimbabwe to do just that. Currently they are painstakingly going through hundreds of hours of video recordings and thousands of still photographs to produce a detailed ethogram of the African elephant. When its published, their ethogram will be the most comprehensive description on the signals of African elephants.
In the meantime we have pulled together everything we know about elephant displays and gestures from the cumulative work of the Amboseli Elephant Research Project. To this knowledge we added displays mentioned in the published work of other scientists. Throughout this process we exchanged information and interpretations with Phil and Billie. We published this body of work on ElephantVoices in 2003 as the Visual Tactile Signals Library. Since then we have updated our work to contribute a chapter entitled, Signals, gestures and behaviors of African elephants for the book, The Amboseli Elephants: A Long-Term Perspective on a Long-Lived Mammal published in 2011. Our current database includes a few changes based on this chapter.
Substantial number of different displays
While anyone who has studied the behavior of elephants will be familiar with the basic displays, it was surprising even to us just how many different displays and gestures elephants use to communicate with one another. Take a look at these on our updated ElephantVoices Gestures Database, which contains entries most with images. While quite a number of these displays and gestures are tactile (see Tactile Communication), most also send a visual message.
So how do elephants send visual signals? The answer in its simplest form is that they use their heads, eyes, mouth, ears, tusks, trunk, tail, feet and even their whole body to signal messages to one another and to other species. For example, a threatening or dominant elephant signals her status by appearing larger, carrying her head high above her shoulders and spreading her ears, while a subordinate elephant carries his head low and his ears back. A frightened or excited elephant raises her tail and chin. A socially excited elephant lifts and rapidly flaps her ears and widens her eyes.
But we would be doing a disservice to the complexity of elephant communication to try to summarize visual displays and gestures in a few paragraphs. We recommend, instead, that you try searching on the database. If you are interested in displays that involve an elephant’s ears, for example, just search on the word "ears". You will find almost a dozen displays listed. Or search on the word "trunk" you’ll find an equal number, try the word "sniff", "touch" or "test" and you will find many more. Or, if you are interested in how elephants signal aggression, sexual interest, playful interaction or friendly concern try searching on the different general contexts.
The eyesight of elephants is said to be good in dull light, but considerably reduced in bright light then reaching a maximum range of 46 m. From personal experience, however, we have found elephants to be rather selective observers, sometimes showing relatively good visual acuity and other times rather poor. Once when Joyce was observing a group of very wary elephants she parked her vehicle on an open hillside some two kilometers from them (unbeknownst to them) and allowed them to walk towards her. They approached to less than 15 m before they saw her, whereupon they fled in panic.
Elephants seem to be able to see silhouettes very well, but are less good at picking out an object against a background In Amboseli where the elephants are very habituated to cars, but are occasionally killed by people on foot, they can become quite alarmed at the sight of a human silhouette. Joyce can, however, stand within a few meters of a group of elephants, with the car as a backdrop and they do not appear to "see" her. This does not mean that they do not know that she is out of the car, however. If we lie down under the car the position of the elephants' trunks as they walk past the car indicates very clearly that they know exactly where we are!
Joyce has also noticed that elephants are sensitive to movement and they seem to be especially cued into the way people (and presumably other predators) move. Walking with a normal gait in front of a group of elephants will immediately attract their attention and they will raise their heads in alarm. Joyce can, however, move past or up close to a group of elephants without attracting their attention by adopting a bent-over posture and moving extremely slowly, freezing each time her movement is noticed.
While it seems that elephants do not have very good visual accuity, they see some things clearly that we see only with difficulty! For example, when an elephant seriously threatens another she will fold the lower portion of her ear back creating what we call an earfold. To our human eyes this posture is rather subtle and it took almost eight years of observing elephants in Amboseli before we noticed earfolding. But Joyce watched two musth males face off with 50 meters between them. Each time the dominant male folded his ears the subordinate male looked or backed away. Clearly the subordinate male could see the higher ranking male folding his ears where Joyce had difficulty seeing the threat from the same distance without her binoculars.
|Last Updated on Thursday, 22 September 2011 06:55|