Sea ice off the southern Labrador coast hasn’t been this high for this date in 20 years: that’s great news for the harp and hooded seals that will give birth at the Front in another few weeks – for a while anyway, because a bumper crop of baby seals is also good news for the polar bears who gather there to eat them.
So brutal, but true. The polar bear must gorge over the short Arctic spring and early summer to survive the rest of the year.
The harp seal is the most abundant seal species in the northern hemisphere (estimated to number more than 9 million animals – that’s more harps than ringed seals) but are found only in the North Atlantic. Partly because they give birth on mobile pack ice, harps have their pups earlier in the season than all other Arctic seals, which means that in some regions, they are a critical food source for polar bears that have eaten little over the winter months.
Although young ringed seals are considered the primary prey of polar bears throughout the Arctic, young harp seals undoubtedly represent an increasingly important resource for populations of Davis Strait, East Greenland and Kara Sea bears.
Most of the harp seals in the NW Atlantic/Atlantic Canada (about 80% of them) have their pups off Newfoundland and Labrador, an area known as the “Front” (the location of my polar bear attack novel, EATEN: special deals all this week). Harps seals at the Front now provide a huge prey base for polar bears of the large (and possibly still growing) Davis Strait subpopulation (photo below courtesy DFO Canada).
There are an estimated 7.4 million harps in Atlantic Canada today (range 6.5-8.3m), an exponential increase over the early 1980s, when perhaps only half a million so remained. Pagophilus groenlandicus was assigned a conservation status of ‘Least Concern’ by the IUCN Red List in June last year (Kovacs 2015), when it was estimated that the global population size of the harp seal was greater than 9 million animals and probably growing1, 2 due to reduced human hunting:
“…harp seals have been harvested for thousands of years but currently the population is large and the number of animals harvested is declining.” [my bold]
Photographers and animial rights activists love cute, fluffy harp seal pups and rarely mention the carnage that goes on in spring as polar bears devour the naive youngsters. See the video below (from 2008), for an example of the cuteness factor.
Posted in Life History, Sea ice habitat
Tagged Atlantic, beaters, Eaten, facts, Gulf of St. Lawrence, harp seal, hooded seal, Labradore, moulting, Newfoundland, polar bear, prey, Red list, seal hunt, spring feeding, video, whelping, whitecoats
Sea ice extent in the Arctic is a bit below average this year at mid-winter but there are no data to suggest this situation will have a negative impact on polar bears.
[Photo above is sea ice off the coast of Labrador, Canada on 26 March 2007 (from Wikimedia): polar bears in the southern portion of the Davis Strait subpopulation have been particularly successful in recent years because in late March through May/June they hunt abundant numbers of young harp and hooded seals in this habitat]
Polar bear researchers presume that most animals eat little to nothing over the winter, because it explains why even non-pregnant bears are at their lowest weight at the beginning of spring.
Sea ice charts and maps below. Continue reading
The other day, I got a call from an international journalist who admitted he’d done no research into the polar bear issue but believed, based on media reports he’d heard, that there must only be about 100-200 bears remaining in the Arctic. I know he’s not alone.
This journalist was utterly astonished to learn that the IUCN Red List assessment in 2015 put the polar bear population total at 22,000-31,000 bears and demanded proof that this was true.
Here is a summary of the Red List report, with references and links to the report:
The 2015 IUCN Red List assessment update for polar bears (published 18 November 2015) states that the global polar bear population is 22,000 – 31,000 (26,000), that the current trend is ‘unknown’ and that there is only a 70% chance that polar bear numbers will decline by 30% in 35 years (with virtually zero chance that the numbers will decline by 80% or more by 2050) – in other words, zero chance of extinction. [Detailed in a document called 22823 Ursus maritimus]. It classifies the polar bear as ‘vulnerable’ to extinction based on predictions of future sea ice decline due to global warming [similar to ‘threatened’ by other organizations] Pdf here.
Below is a list of what truly worrying species declines look like: that is, animals whose numbers have actually declined, no prophesies involved (Adler 2008).
Posted in Advocacy, Conservation Status, Population, Sea ice habitat
Tagged Amur tiger, climate change, decline, elephant seal, endangered, extinction, facts, fur seal, global warming, gray whale, hooded seal, IUCN, polar bear, predictions, projections, prophesy, rare species, Red list, sea ice, sea otter, Siberian tiger, status, Steller sea lion, threatened, vulnerable
Spring is the busiest and most important season for polar bears: it is the most important feeding period and it is also when mating occurs. The fat that polar bears put on during the spring and early summer is critical for their survival over the rest of the year and for females, determines whether they can successfully produce cubs the following year.
Mothers and new cubs emerge from their winter dens in late March to early April and those who have chosen to den on land soon head towards the sea ice. For a fabulous photo of a polar bear female and her two young cubs, just out of their winter den, feeding on a bearded seal pup, pop over here. All other bears, including females with older cubs, will already be on the ice, feeding on the first newborn ice seals of the season and any other seals they can catch.
It’s buffet time for polar bears but the most dangerous time for cute baby seals. Continue reading
Posted in Life History, Sea ice habitat
Tagged bearded seals, Bering Sea, Chukchi, ESA, fat, fat baby seals, harp seal, hooded seal, Hudson Bay breakup, hunting platform, IUCN, ringed seals, sea ice extent