In early October, a few of us were up the hill with the reindeer at about 8pm (the time on the camera was set wrong – definitely wasn’t 3am!), when it was already pitch dark. One of our friends, Sam, had a thermal camera with him that he was playing with, so we thought a few of his photos would make an interesting blog subject.
We always talk about how good a reindeer’s coat is during the Hill Trips – up to 10,000 hairs per square inch of the skin, with a percentage of those hairs (the ‘guard hairs’) being hollow to trap in body heat, and the remaining hairs forming an incredibly dense undercoat. This coat is designed to keep reindeer alive in incredibly cold environments; the recorded coldest temperature that reindeer have been found alive in is -72 degrees Celsius. Thankfully in Siberia and not Scotland!
These are female reindeer Turtle and Mangetout in this picture. You can see that they don’t show up as much as you might expect, and this is down to that super efficient thick coat that is trapping their body warmth in. Most heat is lost around their eyes and muzzles, and you can see heat retained within their coats where the hair is slightly parted.
A little bit of heat is being lost around the base of Scully’s antlers too, but her antlers themselves are in hard bone just now, with no velvet skin covering them – as you can see there is no heat at all coming from them.
Another setting on the camera, showing in colour this time. Again the eyes and muzzle are most obvious, this time on Merida, along with her legs where her coat isn’t as thick.
This photo is interesting for a couple of reasons. This is me (Hen), and look at how much heat is being lost at my neck. My body is showing up relatively well too, although perhaps not as much as expected – however in this picture I’m wearing a long-sleeved thermal top, a t-shirt, a jumper, a bodywarmer and a waterproof jacket, as well as a neck buff and gloves (it was a very cold night, in my defense)! Yet still my body is showing up as warmer on average than a reindeer’s – with a couple less layers on I would have been glowing like the sun!
The other (more) interesting thing in this photo is the set of antlers in the middle of it, belonging to Pip’s big female calf, who’s grown amazing antlers for a calf this year. Unlike all the adult reindeer in these pics, the calf’s antlers are still covered with velvet skin – but one is dark and one is light. At this time of year the blood supply to the calves’ antlers is cutting off, so here the right hand antler is still vascular (has a blood supply) whilst the left hand one has already lost it’s supply. Sure enough when Sam pointed this out, I touched her antlers briefly and the right hand one was still warm but the left one stone cold. How cool – we’d have never have known without Sam’s camera!
The castrated male reindeer mostly still have velvet skin on their antlers just now, but unfortunately there were none in this group that we could point the camera at – it would be interesting to see how vascular they are still, if at all. Another time! In the meantime I’ll stand by my statement that antlers are one of the coolest things in the animal kingdom!
Many thanks to Sam Ecroyd for the use of his photos for this blog.
Hen
