It has been an exceptionally mild winter here in the Cairngorms; the ski season never really seemed to kick off, the herders are missing the snow and it has just felt a bit wetter and warmer than usual. I’m sure you’ve noticed how early the snowdrops and daffodils seem to have emerged and we have noticed that the hills are looking a bit greener with the heather and deer sedge starting to grow already. Looking at the Met Office summary for winter 2016-2017, temperatures are up about 3.0°C on average (average being data from 1981-2010) in the UK.
For the reindeer, this warming winter could have lots of effects, and we have recently heard of the reindeer in the Yamal peninsula, Siberia, starving to death due to increased rainfall in the autumn freezing and leaving a thick layer of ice impenetrable to them for foraging.
Our reindeer seem to be coping just fine and it has not frozen here enough for them not to reach their favourite food, lichen. However, research done by previous reindeer herder Heather Hanshaw has shown that weather conditions do definitely affect the proportion of male to female calves born in the spring. Since calving will soon be upon us, I thought it might interest you to know about this research and what our mild winter may mean for us in the upcoming weeks.
Heather studied Physical Geography at Edinburgh University and in her final year needed a project to study. Of course, having an interest in climate as well as reindeer, and having worked at the Reindeer Centre, a project about how climate affects them was a natural interest to Heather. She knew that Mr Utsi and Dr Lindgren had been very meticulous about the data kept on calves born in the Cairngorm herd, and climate data was easily enough accessed, so Heather devised a project determining if weather (temperature and rainfall) had any effect on the proportion of male to female reindeer calves born. A similar study was conducted with Red deer on the Isle of Rum, and their study found that milder winters led to more male calves. Would it be the same or opposite of Rum, or would weather have no effect on the Reindeer?
It turns out that Reindeer are similar to Red deer and when the winter temperature increases, so does the proportion of male calves. So, will that turn out to be true this year? With only a few weeks until calving begins, it will be interesting to look at whether we have lots of male calves this year.
Last year the winter seemed fairly average, possibly on the warm side a little, and our calving ratio was almost perfectly 1 male to 1 female, so it will be really interesting to see if this mild winter has had an effect on what will be born this May.
Please find sources below.