Behavioral responses of male African elephants (Loxodonta africana) to musth urine.
PI: Susan C. Alberts and Julie Hollister-Smith
Male elephants generally exhibit the dominance relationships seen in males of most mammalian societies; a larger individual is dominant to a smaller individual. However, musth episodes (periods of elevated testosterone and high aggression) temporarily raise a male's dominance position above any non-musth male regardless of size or age. Typified by increased association with females, increased sexual activity, temporal gland secretions and nearly continual urine dribbling, musth has been described as similar to rut in ungulates. Unlike rut, however, musth occurs throughout the year and is asynchronous in a population, so that only a few bulls are in musth concurrently. The mechanisms underlying its onset and duration are not well understood, but age, size and physical condition all affect the likelihood that an individual will experience musth. A single musth period may last from just a few days to over five months, generally increasing as a male ages. Maintaining the condition is energetically costly, thus a male physically declines as it continues. This study explores the potential for chemical signaling between male African elephants via urine dribbling during musth. By examining the temporal patterns of signaling during musth, this study investigates how population level asynchrony of musth may in part be explained by individual economics of maintaining this physiologically expensive condition and of avoiding direct competition with other males in musth. As such, these results may shed additional light on current theories of sexual selection, signaling theory, and male competition strategies. This study also lays the groundwork for future exploration of possible suppression or stimulation of musth in males via urinary signals of musth.
