A new sound in the forest

There is a new sound in the half-light of early morning, a deep intonation that carries well across the otherwise silent forest. This is the roar of a red deer stag, one of at least three on my local patch who are taking part in the annual rut – a seasonal proclamation of ownership of a harem of females. Although typically described as a roar this challenge to other stags recalls the deep bellow of a bull. Unlike their upland cousins these sylvan red deer usually utter a single resonant groan, with long intervals in between each roar. It is an unsettling sound in the half-light, an echo of a time when the woods of Britain were truly wild and inhabited by a range of large mammals now extinct.

The seasonal cycle of sexual activity in red deer is primarily driven by changes in photoperiod (the daily pattern of light and darkness) but it can also be influenced by the condition of the stag. Rutting is a draining experience and a stag may lose up to a fifth of his body weight, predominantly because of his greatly reduced intake of food during the rut. Beginning in late September, the rut itself is initiated by the largest and oldest stags who seek out traditional sites. Male red deer tend not to hold harems of females until they reach five or six years of age but they may find it easier to establish a harem in woodland than on the more open uplands of Britain, where red deer densities can be much greater.

As with many other animals, the act of attracting a mate (or mates in this instance) has become a highly ritualised process. During the rut a stag will not only roar but will also thrash the vegetation, wallow and adorn himself with his own urine. In high density populations, individuals of comparable rank and size may end up fighting. After a roaring contest, the closely matched males may walk side by side, each presenting their bulk to his opponent. Then one individual will lower and turn his antlers, interlocking them with those of his rival. A pushing and twisting contest then follows which, not uncommonly, results in serious injury or even death. The prize in all this display and aggression is access to one or more females and the opportunity to secure parentage of the next generation. While woodland red deer tend to have small harems, with seven or eight hinds in attendance, those on the open uplands will typically hold more females. The rut will continue for several weeks, ending sometime in November. Until then, my morning walks will be blessed by this new soundscape, the roaring of stags.