Red deer breeding earlier in the year

Research into the effects climate change is having on the Scottish red deer population has reported a shift in the breeding season


Red deer in Scotland are starting to breed earlier year on year, a study has found.


Scientists studying the deer on the Isle of Rum have learnt that the rutting and calving seasons now take place earlier, possibly due to climate change. Warmer temperatures in the spring and summer months are providing better grazing conditions for the deer, which is thought to be the reason behind the shift in the breeding cycle.

The study, led by Edinburgh and Cambridge universities, has been on going since 1953 and is one of the longest running of its type in the world. Its current focus is to discover how climate change is impacting upon the red deer population in the region.

Researchers observe the animals in their natural habitat everyday of the year, paying close attention in springtime to the hinds’ udders for signs of pregnancy and the stags’ antlers for any damage as they fight each other for a mate.

Aside from the altered mating pattern, the research has found a link between grass nutrition and antler size. The quality of grazing on the island when the deer are young may have an impact on how big the antlers grow in later life. They have also established that the red deer population is stable because there is an almost perfect balance between births and deaths.


The project’s research is proving to be invaluable information in helping conservation organisations that are responsible for managing the estimated 300,000 red deer in Scotland’s highlands, estates and forests. In the previous years the group’s demographic data has been used by the Scottish government for new policy creation.