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Polar bear team update: It’s all about energy

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Breakfast at 0700 h, then out in the tracked vehicles again, trundling over 1-2 inches of fresh snow, towards the south end of Fletcher Lake at the edge of Wapusk National Park.

Read our previous updates here, here and here.

By Peter Ewins

Mayor Mike Spence and his tracking-expert brother Morris tell us joyfully that “this is the warmest day this year” – a mere 35 degrees C below zero, positively balmy! (it would be totally ‘barmy’ if we didn’t all have the top-grade cold weather clothing of course, and those fabulous Canada Goose expedition parkas!). Rhys and I have a little touch of mild frostbite on our fingertips, due to the work with the tripod, cameras and binoculars, but when you’re 100 metres away from these magnificent animals, you don’t seem to feel the cold that much!

Morris had found another set of tracks of a female with single cub (the commonest litter size this year – clear evidence of the continuing declines in mean numbers of cubs emerging from the maternity dens). But on the way there, we came across tracks of a female and THREE cubs!

(c) Rhys Gerholdt/WWF(c) Rhys Gerholdt/WWF

Thirty minutes later, I was in the company of my very first family of three polar bear cubs. OMG!! How cute and entertaining can one get ?!! What a lucky man I am indeed – in fact all of us there felt so privileged to spend three hours in their company, on that sunny but spine-chilling tundra afternoon.

In the period 1980-1992, mean litter size was 1.84 – ranging between 1-3, and in one case, 4 cubs emerging from dens. Two-thirds of these families were of twins, with only 12 percent of mums producing triplets. Recently, we have been seeing mainly single cubs, and tracks of single cubs with mum – likely due to declines in litter size, and perhaps early life survival associated with increasing energy stress on pregnant females and earlier sea ice melt in spring in southern and western Hudson Bay.

But what is remarkable today is the huge size difference between the first two cubs, and the third – ‘Tiny Tim’ as one photographer called him or her! I estimated that the body mass of the little guy was probably less than one-quarter of that of the two siblings.

Dr Nick Lunn continues his helicopter-based research this week out on the sea ice along the coast – funded by WWF too – and reports rather skinny mums in general, with one single cub weighing in at a very respectable 36 lbs, but the smallest cub in the only triplet family he came across on the sea-ice being only 14 lbs. I’d guess that our poor wee guy could well have weighed under 10 lbs. He had to scamper flat-out to keep up with the rest of the family – ploughing through the 2 inch drifts with difficulty but great determination (see photo). Mum and the two sibs usually stopped every 30 metres or so, and mum looked anxiously backwards as ‘Tiny Tim’ caught up. But she didnt seem to be a skinny mum, and clearly nursed all three cubs at one time. There was lots of fur licking going on, and at this stage anyway, no signs of sibling aggression.


We all marveled at both the strength yet fragility of nature on this memorable afternoon. Here is the world’s largest land carnivore, producing fragile cubs, only 1 – 1.5 lbs in weight, in some of the harshest conditions on Earth. Yet if they survive the early-life dangers and food shortages, then they will become such strong powerful predators, capable of killing a huge bearded seal or even walrus sometimes.

And yet, we reflected as we bounced home toward Wat’chee lodge, how this superbly adapted animal in these conditions was as much on the edge as any other animal or plant, so vulnerable to the rapid unprecedented changing conditions that climate change is imposing on their home, the Arctic ecosystems. We wondered just what kind of world those cubs who survived in this family would be in, say in another 25 or 30 years when they were their mum’s age? And whether Tiny Tim as the third guy in the troupe would even make it out to the sea ice, another 50 km to the east…

Our end-of-day discussions then wandered full-circle back to the ambitious yet totally necessary targets WWF and many others have set now for a truly manageable and sustainable future, where humans indeed have the potential to live in harmony with nature, by shifting to a renewable energy-based economy in the next 40 years.

The female polar bear’s game plan in order to raise cubs is set in a very similar way to an airline pilot having to load aviation fuel on for a long journey – you have to get your destination but with sufficient fuel on board for the projected conditions.

Pick your route, the use your fuel very carefully for the conditions, and most important – make sure you’ve got enough fuel aboard before you take off!

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