Musth or must is a periodic condition in bull elephants characterized by highly aggressive behavior and accompanied by a large rise in reproductive hormones. Testosterone levels in an elephant in musth can be on average 60 times greater than in the same elephant at other times. However, whether this hormonal surge is the sole cause of musth, or merely a contributing factor, is unknown. Scientific investigation of musth is problematic because even the most placid elephants become highly violent toward humans and other elephants during musth.
Cause
Although it has often been speculated by zoo visitors that musth is linked to rut, it is unlikely there is a biological connection because the female elephant's estrus cycle is not seasonally-linked, whereas musth most often takes place in winter. Furthermore, bulls in musth have often been known to attack female elephants, regardless of whether or not the females are in heat.
Effects
Secretions
Elephants in musth often discharge a thick tar-like secretion called temporin from the temporal ducts on the sides of the head. Temporin contains proteins, lipids, phenol and 4-methyl phenol, cresols and sesquiterpenes. Secretions and urine collected from zoo elephants have been shown to contain elevated levels of various highly odorous ketones and aldehydes. The elephant's aggression may be partially caused by a reaction to the temporin, which naturally trickles down into the elephant's mouth. Another contributing factor may be the accompanying swelling of the temporal glands. This presses on the elephant's eyes and causes acute pain comparable to severe root abscesstoothache. Elephants sometimes try to counteract this pain by digging their tusks into the ground.
Behavior
Musth is linked to sexual arousal or establishing dominance, but this relationship is far from clear. Wild bulls in musth often produce a characteristic low, pulsating rumbling noise which can be heard by other elephants for considerable distances. The rumble has been shown to prompt attraction and reply vocalizations from cows in heat, but silent avoidance behavior from other bulls and non-receptive females, suggesting an evolutionary benefit to advertising the musth state. Cases of rogue elephants randomly attacking native villages or goring and killing rhinoceroses without provocation in national parks in Africa have been documented and attributed to musth in young male elephants, especially those growing in the absence of older males. Studies show that reintroducing older males into the elephant population of the area seems to prevent younger males from entering musth, and therefore, stop this aggressive behavior.
In domesticated elephants
A musth elephant, wild or domesticated, is extremely dangerous to both humans and other elephants. In zoos, bull elephants in musth have killed numerous keepers when normally friendly animals have become uncontrollably enraged. In contrast to normal dominance behavior, bulls in musth will even attack and kill members of their own family, including their own calves. Zoos keeping adult male elephants need extremely strong, purpose-built enclosures to isolate males during their musth, which greatly complicates the expense of attempting to breed elephants in zoos; most zoos that keep a single elephant or a small herd typically have only females for this reason. In India, domesticated elephants in musth are traditionally tied to a strong tree and denied food and water, or put on a starvation diet, for several days, after which the musth passes. Mahouts are often able to greatly shorten the duration of their elephants' musth, typically to five to eight days; sedatives, like xylazine, are also used. The approved method in developed countries is to strictly isolate the elephant in a highly fortified secure pen for a period ranging from 1 to 2 months until the elephant emerges from musth on its own. Medication for swelling and pain, as well as tranquilizers, are often mixed into the elephant's food. During this one- to two-month period the elephant cannot be trained, allowed outside or permitted to see other elephants, and it must be fed, watered and cleaned by remote methods; it will attack any approaching keeper. Some Indian mahouts decry this method as crueler than simply starving and dehydrating the animal for a week, after which it recovers and can be safely reunited with the herd.
