Musth and elephant Society

Article by: Rob Slotow¹ and Gus van Dyk²

¹ School of Life and Environmental Sciences, University of Natal, Durban.

² North West Parks and Tourism Board, Pilanesberg National Park.

The word "rogue" conjures up images of Wilbur Smith characters pressing forth beyond the frontiers of civilised behaviour, and into the wild unknown of darkest Africa. It was here that European explorers and hunters left civilised expectations behind, and slaughtered amongst others, the vast herds of African elephants. Profound changes must have occurred in the social fabric of local elephant societies, and with the breakdown of the existing social hierarchies and systems, aberrant behaviour ensued, and numerous hunters met a sticky (tusky ‘sic’) end. Encounters between humans and aggressive elephants increased, and the dogma was born of a rogue elephant, or one that was out of control, and would probably kill a human unless it was eradicated.

No one could offer an explanation of why male elephants tossed their toys out of the cot. That is until the early 1980’s, when Joyce Poole studied male African Elephants at Amboseli National Park in Kenya. Joyce Poole began by identifying individuals using ear notches and tears, and broken tusks. Once she had a mug shot for the local bulls, she could begin to understand the nuances of their society. While following the elephants around, Joyce noticed some of the males displayed unusual symptoms and characteristics. Some males showed "tears" streaming down the side of their faces (secretions from temporal glands), and continual dripping of urine onto their legs. Besides these physical changes, there were associated changes in behaviour. Males that were streaming tended to follow females that were in oestrus, and were markedly more aggressive than others. Because Joyce could identify each male, she noted a predictable cycling of each male from year to year. She concluded that African elephants displayed Musth, a condition first described in Indian Elephants in the 19^th Century.

Typically, females form groups comprising a number of families consisting of a mother, and her offspring of different ages. These separate and reform depending on current resources. Adult males on the other hand, separate from these family herds, and spend most of their time in the "bull areas", which family groups typically avoid. This is an area, infrequently visited by the breeding herds, where elephant bulls spend much of their leisure time building up strength and sorting out the bull hierarchy; a sort of men’s club. As the bull feels the urge, or the rumblings of an upcoming musth period, he leaves the bull area in search of the herds and any mating opportunities.

Within bull areas, males encounter each other, and fight over resources such as access to food and water. Bulls establish a dominance hierarchy based on size, with the larger bull being dominant over smaller ones. Musth males are more aggressive probably as a result of higher levels of testosterone, and most other males will avoid a musth bull. Musth changes an individual’s position in the hierarchy, and any bull that is in musth automatically becomes dominant to any bull that is not in musth. This is regardless of size, so that even a young bull can chase off a large patriarch. Musth bulls leave bull areas and move after female herds, seeking out a receptive female in oestrous. Receptive females are the ultimate resource and musth bulls encountering each other with the herd may fight to the death.

We are not really sure why elephants enter musth. Individuals that do enter musth manage to exclude all other non-musth individuals from females that are ovulating. This means that they will get to father more offspring and any characteristic or behaviour that allows this will be favoured by natural selection. It is simple to imagine a situation where females stimulated some males to secrete more testosterone. They in turn were more successful at excluding other males from those females because they were much more aggressive, and determined to enter and prolong clashes with other males. This characteristic would quickly spread through the population.

It is all well and good being a very aggressive elephant, and capable of winning any fight. However, it would be even better if you could advertise this to the world at large, in which case you wouldn’t have to fight very often. Kind of like wearing a pair of well-scuffed boxing gloves around your neck. Anyone who sees them will immediately place you as a fighter, and will avoid spilling their drink on your new suit. That is, anyone who wasn’t a boxer themselves. Bulls in musth typically stream secretions from their temporal glands (tears on the side of their heads). This may be a route for secretion of excess testosterone, which in large concentrations can be deadly. These secretions could also be a means of signalling to other individuals. Prof. Liz Rasmussen has described several volatile compounds from the temporal secretions, and these could well signal to other individuals a wide range of messages. The most perplexing aspect of musth is the continual streaming of urine down the legs of the males. It seems incredible wasteful for gallons of liquids to flow out of an animal that spends most of its time walking between water holes. Besides the waste, there is always the risk of infection, especially seeing the penis becomes coated in an algal layer, giving it a green sheen, and resulting in the nickname of GP-syndrome, or green penis syndrome of the highest level of musth. Perhaps this is also a signal to other males to stay away. A musth bull certainly has a distinctive smell! It could also be a signal to the females. Perhaps it indicates to them that this is a high quality bull. Not only has he managed to exclude the other males from accessing her, and survived the threats of rot and disease but he can afford to spend the whole day following, and still gather enough water to produce all that urine. Certainly the kind of male to father my kids!

Elephant males are able to reproduce from around their eighteenth birthday. However, it would be an extremely unusual event for a bull younger than 30 to mate with a female at the height of her oestrus. At all times there would be at least one large adult musth male with the herd about who would displace any young pretenders. In fact, older bulls that are in musth actually suppress the musth cycle of less dominant younger bulls to the extent that they will fall out of musth a few days. This results in a stable hierarchy of bull elephants, with the older more experienced bulls coming into musth for a full period of three to five months a year, and less dominant bulls being in musth for relatively shorter periods. The most subordinate bulls would be those that have just left the breeding herd, and those will not come into musth at all. Joyce Poole found that Amboseli bulls only enter a sustained period of musth at about 30. Up until then, although they will start musth, and will show a lot of the symptoms, younger bulls will not achieve full musth. A consequence of this hierarchy is that when a bull does actually enter musth he has the experience to cope with the circumstance of being cock-full of testosterone in the presence of a group of receptive females, and in a bunch of like-minded guys. The goal of introducing Kruger elephants to Pilanesberg (and now Hluhluwe-Umfolozi Park) was to establish such a bull hierarchy. This would prevent young males from entering sustained musth until they could manage it.

The problem - background

The solution

Hluhluwe-Umfolozi Elephant Project

Pilanesberg Elephant Project