Musth in the male elephant

Compared to other land mammals, a strikingly different feature of the male elephant's reproductive system is that the testes are located within the abdomen. During the fourth century b.c., Aristotle wrote in his Historia Animalium that, "The penis of the elephant is like that of the horse, but small considering the animal's bulk. The testes are not visible externally, but are placed inside, near the kidneys." The musculature of the penis gives it an S-shaped flexure when erect, thereby enabling it to hook into the forward-directed vagina of the cow. Another characteristic observed in the male elephant's anatomy is that macroscopically it is not possible to differentiate an epididymis from the duc-tus deferens, which along with the longer Wolffian duct, conveys the semen from the testes to the urethra. The accessory organs include the seminal vesicles, the prostate gland, and the paired bulbourethral glands.

Puberty in the male can be defined as the first production of viable sperm, while it can be said that sexual maturity has been attained when a dense mass of motile sperm is produced. As with the female elephant, the age of puberty and sexual maturity in a bull may vary across populations, depending on habitat factors. Richard Laws generally found a close correlation between reproductive maturity in males and females of an elephant population, although this could vary by as much as 6-10 years across populations. The onset of puberty in male elephants may occur anywhere between 8 and 15 years of age, while sexual maturity takes 2-3 years longer. I must emphasize here that enormous variation exists, and that observations in zoo animals cannot be taken as indicative of wild populations.

Sexual maturity in a bull elephant eventually has to lead to sociological maturity if it is to reproduce successfully in the longer term. This takes us to an aspect of a bull elephant's biology known in Asian elephants since ancient times, but recognized in African elephants only recently. The adult male elephant goes through a period of intense aggression toward other males and sexual interest in estrous females, a phenomenon termed musth. A bull elephant in musth secretes a fluid from its temporal gland and may constantly dribble urine. The term musth comes from an Urdu word for intoxication. The phenomenon of musth has been well documented in Asian elephants since ancient times. In the Rig Veda (1500-1000 b.c.), the simile of a bull elephant in musth is used to describe the indomitable strength of Indra, the king of the gods. The ancient Indian epic, the Mahabharata, speaks of warriors riding into battle on elephants in musth. Perhaps the most apt description of musth is found in Nilakantha's Matangalila: "Excitement, swiftness, odor, love passion, complete florescence of the body, wrath, prowess, and fearlessness are declared to be the eight excellences of musth." That single sentence alludes to aggressive behavior, chemical signaling, and the sexual connotations of musth.

The long history of keeping elephants in captivity in Asia undoubtedly provided the opportunity for observing musth and associated behaviors. The scientific literature on African elephants was, however, rather confused on the issue of musth. Both female and male African elephants secrete from their temporal glands, often in response to disturbance or stress in the environment. Observers of African elephants during the 1960s and 1970s thus attributed a chemical signal function to this secretion, which they called musth. They further postulated that temporal gland activity had entirely different functions in the Asian elephant and the African elephant, a sexual role in males of the former and a communication function in both sexes of the latter species.

An article by Joyce Poole and Cynthia Moss in 1981 firmly established that adult bull elephants in Amboseli National Park exhibited the physical and behavioral characteristics of musth similar in all aspects to the male Asian elephant. This was distinct from the temporal gland secretion of immature and adult females and males of African elephants, which should be termed temporin, and plays a role in communication among individuals in a social group. The term musth had been wrongly applied to any kind of secretion from the temporal glands in either males or females. Further, female Asian elephants had almost never been observed to have active temporal glands and thus were not considered to come into musth like their African counterparts (see chapter 4).

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