Hot hot hot!

Whilst we’re lucky enough to live here in the Cairngorms, the only area of sub-arctic ecosystem left in the UK, and generally associated with snow and winter sports, we do (occasionally!) get some glorious sunny weather too. Loch Morlich beach turns into a resort, people are braving a dip in the water, and ice creams are being consumed.

A sunny day at Loch Morlich, © Mike McBey, shared under licence CC by 2.0

But what happens to those arctic survival specialists that we look after, the reindeer? I have to say whilst I look forward to the sun, my heart also sinks a little that the herd are going to be unimpressed.

Reindeer are native to this area and habitat, as well as being found right across Scandinavia and Russia. And although those areas experience extreme cold, the summer temperatures rise to a similar level as here at Cairngorm. I actually looked up some average temperatures of prime reindeer herding locations in Sweden (Kvikkjokk by Sarek National Park) and Norway (Tromso) and compared them to Cairngorm.

Cairngorm, Scotland – thanks to worldweatheronline.com
Kvikkjokk, Sweden – thanks to worldweatheronline.com
Tromso, Norway – thanks to worldweatheronline.com

It was interesting to see that their average summer temperatures actually exceed ours here, though they have much colder, and longer, winters. So, reindeer are definitely able to cope with the warmer temperatures – how do they do this?

Crann moulting his winter coat, with a little human assistance

Firstly, the reindeer have a much shorter, cooler summer coat than their insanely thick winter coat. From May they are moulting rapidly, looking like shaggy beasts with bad hair-dos, though with so much fur to lose it can take them until July to be fully into their sleek summer outfit. This must be much nicer for the sunny days – like when you’ve had a haircut and can feel the breeze on your neck!

Male reindeer in their short summer coats

Whilst reindeer don’t sweat like humans, they instead act like (large, overgrown, funny looking) dogs – flopping down and panting. This can look quite dramatic as their whole body moves with each breath, but it does seem to work. They do like the shade and will often sardine themselves into the shed in our Hill enclosure!

Another technique is to pee… a lot! By peeing, hot liquid is expelled from the body, and is replaced with cooler water as they drink to replace it, almost like an internal cooling system.

Anster can pee for Scotland! © Hen Robinson

Reindeer also become “Beasts of the Bog” and disappear into muddy ditches and hollows, often lying down to cool their bellies. They will occasionally wade into pools and have even been known to swim in the loch – they are of course marvellous swimmers with their huge hooves.

Calves learn the art of bog wallowing at a young age © Lotti PB

The herd also tend to naturally choose the higher ground on hot days – in general there is a 1ºC drop in temperature for every 100 m gain in height (due to the lower air density), and this, along with the greater likelihood of a breeze to cool them, means the ridges and high tops of mountains are preferred when the sun is out. Up there, there is also more chance of late-lying snow drifts – even as late as August here in the Cairngorms, which are the ultimate cool bed to lie on!

Reindeer on a last snow patch © Gary Hodgson Photography of www.tarmachan-mountaineering.org.uk

So, while I do feel sorry for our reindeer on hot cloudless summer days, as they would much prefer the snows of winter, it turns out that they are pretty well adapted to cope with whatever the weather throws at them!

Andi

Spring Buds

If I was a gardener I would be looking out for the first signs of spring, daffodils pushing out of the ground and buds beginning to form on the trees. But I’m not. I’m a reindeer herder so the buds of spring I look out for are the newly growing reindeer antlers which begin to grow first among the mature bulls.

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Yearling reindeer Fly a few years ago, with new antlers just starting to ‘bud’.

Having lost their old antlers at the end of last year our mature bulls, like Balmoral, Bovril and Pera have spent the last few months antlerless which is not a good place to be because with no antlers you are at the bottom of the peck order. Even the wee calves, only 10 months old, still have their antlers and can boss any antlerless reindeer around!

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Fly a few days ago having cast an antler a little early, and presumably with ‘help’ from another reindeer. Antlers cast naturally  in Spring don’t normally bleed.

Mature bull reindeer grow the largest antlers in the herd and so to achieve this they need to start growing their antlers early. Despite still being winter here the bulls will divert food resources to growing these new antlers and this week I have just noticed the first buds of velvet antler appearing on their heads.

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Mature bull Crann in his heydey, with antlers starting to grow long before the end of winter.

Velvet antler is the fastest growing living tissue in the animal kingdom and from nothing on their heads these bull reindeer will have fully grown antlers, measuring up to 1 metre in length and weighing anything up to 10kg by the middle of August. Although the rate of growth will be slow just now, by the spring/summer the antlers visibly grow each day, with a growth rate of about 1cm/day.

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Crann in May with half-grown antlers…

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…and in August the same year, with full grown antlers.

Antlers are entirely composed of bone and to grow need a blood supply to the growing tip. The blood supply is carried by the velvet skin covering the developing bone and the velvet skin also acts as a protective cover. The velvet is also full of nerves, which make the growing antlers sensitive to contact, so protecting the soft growing tissue from injury.

Because the blood is so close to the surface the antlers always feel warm and radiate considerable heat. Indeed some scientists suggest that the antlers are important radiators of heat that help reindeer to ‘keep cool’ in the summer time.

The ultimate size of the bulls antlers depends on a number of factors but genetics and nutrition are the most important ones. The more they eat the bigger their antlers grow and if they come from parents who grew big antlers then they will more than likely grow large ones themselves. Crann has grown the biggest antlers ever in our herd and that is partly due to his parentage, his mother Burgundy grew extremely big antlers for a female. But also Crann has an insatiable appetite, always there for extra food, despite being an old reindeer now!

Tilly