ruttningen

Ruttningen, often called the rut, is the annual mating period in many deer species and other ungulates. It is driven by seasonal changes in daylight that triggering hormonal shifts, particularly a rise in male testosterone. This hormonal surge leads to increased aggression, heightened sexual signaling, and territorial behavior as males compete for access to receptive females.

During the rut, males engage in conspicuous activities such as antler displays, sparring or fighting with rivals, loud vocalizations, and scent-marking to attract females and deter competitors. Females enter estrus during this period and may mate with multiple males, a pattern that can influence paternity on the population level. Mating typically occurs over a relatively short window, followed by a gestation period that results in the next generation months later, depending on the species.

Timing and duration of ruttningen vary by species and region. For example, roe deer tend to rut in late summer to early autumn with a peak in August, while larger cervids such as red deer and moose commonly rut in autumn, with regional peaks influenced by latitude and local ecology.

Ecological and human dimensions are significant. The rut affects population dynamics, survival, and recruitment, and can alter predator–prey interactions. It also has practical implications for wildlife management, hunting seasons, and agricultural areas, where increased movement and vocal activity during the rut may influence livestock protection and crop damage.

In summary, ruttningen is a hormonally driven, seasonally timed reproductive period marked by male competition, female receptivity, and notable ecological and management implications.