By Peter Ewins
Rhys and I awoke to a crystal clear dawn, a numbing -40C again, and the excitement of reconnecting with the female polar bear and her single cub that we had left at sunset yesterday evening. After one of cook Daryl’s splendid tundra breakfasts at Wat’chee lodge, we headed out in the tracked vehicles with top-notch photographers from around the world, and the ABC news crew.
After rattling and rocking at about 15km/hour over the frozen tundra, avoiding all the deep drifts, we reconnected with the family. They had moved about 4km east, steadily heading for the sea ice (another 40km or so still to go before mum could have a chance of her first meal since last June – yikes, what must that feel like?! Mum and cub were sleeping in the lee of a bunch of willow bushes, then junior woke up and then started playing with and bugging mum! We quickly spotted that mum had a radio collar on her neck – which would have been fitted by the research biologists in their important studies of polar bear movements and population ecology in relation to rapid climate change. WWF has been supporting these studies regularly for the past 30 years, and now profiles the movements of a sample of these bears.
When mum didn’t respond to his play jabs, the cub then started chewing and fiddling with the scientists’ radio collar – hilarious! But we paused to recall that the steady reduction in mean litter size and number of cubs, as the sea ice season shortens further due to climate change, means that there are far more single-cub families than in the late 20th century here in West Hudson Bay.
After sniffing the wind many times, probably checking for signs of wolf packs, mum and cub headed eastwards – but so slowly when they encountered deeper snow drifts, for even this tough young bear struggles when he falls into drifts. That slow pace emphasised for us how critical energy is for these animals – that wee cub was powered entirely by mum’s milk, which was derived entirely from the vital 200kg or so of fat which she had to store the previous April-May out on the sea ice.
And as the recent science papers have shown, further reductions in that spring sea ice period would lead to sharp decreases in the number of females able to store enough fat to sustain the pregnancy and produce enough surviving cubs to balance adult deaths in the population.
One interesting thing we discovered today was that a government scientist (Dr. Nick Lunn) is also doing surveys further along the coast. He says that this female might well be the one with a satellite radio collar on which is currently showing on the map as being in this part of Wapusk National Park. If that the case, then Nick knows from the great records they have been able to keep over the years that this is a 23-year old female – well into her active breeding years. Tremendous to see this type of information available and so useful. It emphasises for me just how important these long-term wildlife studies are, and how important support from WWF is to ensuring we understand enough about the wonderful natural world that we share with these amazing animals.