Musth is a phenomenon in male elephants that marks a period of sexual activity. Musth generally starts when a bull is in their 20s and, in a healthy bull, may continue to their 50s or 60s. The exact ages that musth begins and ends can vary greatly by individual, so there is no hard starting or stopping point in a bull’s lifetime for musth.

While in musth, bull elephants significantly alter their social behaviors to prioritize seeking out a mate. This urge to procreate is caused by a spike in their reproductive hormones; testosterone levels, for example, can increase up to 100x their baseline levels during musth!

Musth can be observed in captive and wild populations as its primary determinant is good health. Unfortunately, musth is challenging to manage in captive bulls because of the drastic behavior changes and increased aggression accompanying the testosterone spike. This can majorly impact bull elephants’ welfare, and living conditions as captive elephants in facilities with poor management practices are often starved in hopes their malnutrition will cause them to drop out of musth. This can and does kill captive elephants yearly.

How Often Do Elephants Go Into Musth?

Bull elephants go into musth about once a year, with each cycle usually lasting between two and four months. The length of musth often depends on the bull's health; however, additional factors, such as age, can come into play when estimating how long a bull will be in musth. There are many cases of bulls going into musth for just a couple of days and others that stay in it for up to a year.

Musth generally comes in phases, with the lengths of each varying slightly by the individual:

Pre-musth lasts approximately 1 month
Peak musth lasts approximately 1-1.5 months
Post-musth lasts approximately 1-1.5 months

Why Don’t Female Elephants Get Musth?

Female elephants do not get musth and instead have an estrous cycle which takes between 13 and 18 weeks to complete. Their estrous cycle length makes them receptive to pregnancy around three times a year for six to 12 weeks per cycle. The estrous cycle differs significantly from musth because female and male hormones and reproductive tracts differ in many ways. Therefore, the behavioral shifts and symptoms that male elephants experience during musth do not apply to female elephants.

Does Musth Make Elephants More Aggressive?

The dramatic increase in testosterone in a bull elephant’s body during musth can cause them to be unpredictable, hyper-reactive, and more aggressive. There are endless stories on the internet recounting dangerous and even deadly encounters with elephants in musth, both in captive and wild environments. That’s why it’s crucial that you can tell the signs of musth if you plan to explore native elephant habitats or interact closely with captive bull elephants.

How Can I Tell if an Elephant is in Musth?

The easiest way to tell if a bull elephant is in musth is to see if they are secreting from their temporal glands. The temporal glands are located between the eyes and ears on the elephant’s temples, and when looking closely, you can see a small hole where the gland is located. During musth, bulls secrete a hormone-rich liquid called temporin from their glands which leaves a stained wet streak down the sides of the face. Based on how far down these streaks go, you can tell whether they’re in peak musth or pre/post-musth.

Another sign of musth is wetness on the insides of the back legs. While an elephant is in musth, he drips urine from the penis onto the legs; similarly to the temporal gland secretions, the intensity of the urine spots on the legs can indicate which phase of musth the bull is in. Female elephants can smell these hormone-rich secretions from miles away to know that a bull is in the area. And although elephants have a much more developed sense of smell than we do, humans can also smell musth secretions.