Straying female deer play a significant role in determining which rutting stag gets the girl, a long term study shows.
Red stags often conjure an image of mighty presence and power, especially during the rut, or mating season.
At this time, stags compete for the attention of potential female groups called ‘harems’. Fighting often occurs between males for dominance.
However, a study carried out on the Scottish Isle of Rum suggests that during the rut, females are drifting from their usual areas and therefore snubbing potential mates.
Scientists from the University of Edinburgh and Cambridge have been analysing 34 years' worth of data collected on this behaviour.
Findings show that up to 43% of female deer in heat will drift from their typical range, with some travelling up to 4km.
Almost half are shown to mate with stags from another area.
Researchers are not entirely sure why the females wander off but believe it appears not to be out of preference for another stag.
The study highlighted that females in heat do not favour large harems, older stags, or distantly related stags.
The study, funded by the Natural Environment Research Council and the James Hutton Institute (formerly The Macaulay Institute) was published in Behavioral Ecology.
Rum is a National Nature Reserve managed by Scottish Natural Heritage.
Females change harem during the autumn rut far more than we would expect. They are much more likely to do so when they are receptive to mating. Further research is needed to understand fully why this occurs and what the implications may be.