Tag Archives: spring

Polar bear habitat update mid-May: little change since 1989 despite CO2 increase

Sea ice habitat for polar bears has not become progressively worse each year during their season of critical feeding and mating, as some scaremongers often imply. It’s true that absolute extent of Arctic ice is lower this spring than it was in 1979. However, according to NSIDC Masie figures, polar bear habitat at mid-May registers about 12 million km2, just as it did in 2006 (although it is distributed a little differently); other data show spring extent has changed little since a major decline occurred in 1989, despite ever-rising CO2 levels.

Polar bear feeding_Shutterstock_sm

In other words, there has been virtually no change in sea ice cover over the last 12 years, despite the fact that atmospheric CO2 has now surpassed 410 parts per million, a considerable and steady increase over levels in 2006 which were about 380 ppm (see below, from the Scripps Oceanographic Laboratory, included in the Washington Post story 3 May 2018):

Scripps CO2 curve at 29 April 2018

Not only that, but if rising CO2 levels were responsible for the decline of sea ice and implied effects on polar bears since 1979 (when CO2 levels were around 340 ppm), why has spring ice extent been so variable since 1989 (when the first big decline occurred) but so little changed overall since then? See the NSIDC graph below for April:

Sea ice 2018 April average_NSIDC graph

This year on day 134 (14 May), global ice cover registered 12.3 mkm2:

masie_all_zoom_4km 2018 May 14

In 2016 on the same day, the overall extent was much the same but there was more ice in the Chukchi and Bering Seas and less in the eastern Beaufort:

masie_all_zoom_4km 2016 May 14

More close-up charts of different regions below for 2018 vs. 2016, showing more detail.

Continue reading

Polar bear habitat update early spring 2018

Spring in the Arctic is April-June (Pilfold et al. 2015). As late April is the peak of this critical spring feeding period for most polar bear populations, this is when sea ice conditions are also critical. This year, as has been true since 1979, that sea ice coverage is abundant across the Arctic for seals that are giving birth and mating at this time as well as for polar bears busy feeding on young seals and mating.

Polar_Bear_male on sea ice_Alaska Katovik Regehr photo_April 29, 2005_sm labeled

Below is a chart of sea ice at 25 April 2018, showing sea ice in all PBSG polar bear subpopulation regions:

masie_all_zoom_4km 2018 April 25

Some Arctic subregions below, in detail. Continue reading

Amstrup & colleages can’t refute my critique of their 2007 polar bear survival model, Part 2

Polar bear specialists Andrew Derocher and Steven Amstrup recently spent inordinate energy trying to refute the opinion piece I’d written for the Financial Post in celebration of International Polar Bear Day last month, ignoring my fully referenced State of the Polar Bear Report for 2017 that was released the same day (Crockford 2018) and the scientific manuscript I’d posted last year at PeerJ Preprints (Crockford 2017).

polar_bear_USFWS_fat Chukchi Sea bear

Their responses use misdirection and strawman arguments to make points. Such an approach would not work with the scientific community in a public review of my paper at PeerJ, but it’s perfect spin for the self-proclaimed “fact-checking” organization called Climate Feedback. The result is a wildly ineffective rebuttal of my scientific conclusion that Amstrup’s 2007 polar bear survival model has failed miserably.

This is Part 2 of my expose, see Part 1 here.
Continue reading

Much more sea ice in NW Hudson Bay this year than 2016 or 2015 at 27 May

In recent years, sea ice loss over Hudson Bay has begun with open water in the NW corner (which is just as likely due to prevailing offshore winds as ice melt) rather than along the east coast but this year that patch of ice is smaller than its been for the last two years. In addition, despite two patches of open water at either end of the Beaufort Sea, most of the coast of Alaska is still covered in thick ice — much more than existed last year, yet masses of polar bears did not die as far as I know (actually, WHB bears came ashore in excellent condition last year).

Sea ice Canada 2017 May 27

Compare to previous years:

Continue reading

Newfoundland conservation officers right to kill polar bear in hunting mode

Apparently, some locals were upset that a polar bear that refused to be scared away from a Newfoundland community over the weekend was shot as it advanced on conservation officers and a crowd of onlookers who refused to disperse (see updated report here on recent Newfoundland polar bear sightings, with annotated map).

Catalina map and bear shot location Nfld

Polar bear shot by wildlife officers near Catalina after being deemed public safety risk” (CBC 10 April 2017)

What these animal lovers may not realize is that Newfoundland in March and April is not a Churchill-like situation: polar bears are in strong hunting mode right now.

Polar bears in late winter and spring have an immense drive to kill and eat as much as possible. Even bears that look well fed will continue to kill and eat. Enticing smells attract them onshore as they investigate any food possibility (see list below).

Seriously, you don’t want that food possibility to be you.

Polar bears can go from watching to charging, in the blink of an eye. You can’t outrun one. Killing quickly is what they do and they are immensely strong. Polar bears generally go for a killing bite to the head. Things to think about when a polar bear is prowling your community…
Continue reading

East Coast crawling with polar bears since early March thanks to the pack ice

The  hot polar bear news right now is the large number of sightings of bears onshore in Newfoundland and Labrador – even the CBC is impressed.

Melrose nfld Polar Bear 02_2017 April 3_Brandon Collins shared photo The Packet

Photo taken by Brandon Collins in Melrose (on the Trinity Bay side of the peninsula) Monday 3 April 2017

All the bears have been brought to land by the abundant pack ice that’s been present off Labrador and northern Newfoundland (the territory of Davis Strait polar bears), which also killed a humpback whale that got trapped against the north shore (a not unusual event, apparently).

Mapping the reports of polar bear sightings since early March helped me get a handle on the total number of encounters: more than a dozen, it turns out.  There have been a few bear sightings in this region every year recently but such high numbers are remarkable, especially so early in the season. When will it end?

Increased numbers of bears in the population is one explanation for increased numbers of encounters onshore at this time of year, although recent storms may have encouraged more bears than usual to come ashore in Newfoundland.

My picture annotated map and a list of sighting reports, with links, is below but stay tuned: this story may not be over yet.

UPDATE 4 April: more photos and sea ice maps added below.

UPDATE 5 April: another sighting, in St. Brendan’s (west of Bonavista), added to the map below and quotes from one witness. The map is now Version 2. A sea ice map for 5 April has also been added at the end of the post.

UPDATE 9 April: another sighting and a bear casualty, see below. Map revised again.

UPDATE 14 April: CBC Newfoundland article (12 April: Highway of ice: Easy route for polar bears chasing food, prof says) based on my radio interview that aired 11 April.

UPDATE 22 April: Another sighting west of St. Anthony on Wednesday, 19 April has been added to the map (now Version 4) and an alert that I’ve added a new post (21 April) about the claim by one vocal polar bear specialist that all of these sightings are the result of “failed” sea ice conditions off Newfoundland and Labrador this year (seriously, I’m not making this up). I’ve added the most recent ice map at the end of this post.
Continue reading

More polar bear habitat in Hudson Bay region at mid-May than in 2006 & 2011

What a difference a bit of historical perspective can make to one’s attitude on the annual Arctic sea ice breakup.

masie_all_r10_v01_2016137_4km

The usual recent pattern (since 1979) has been for breakup to begin on the east side. However, this year and last (below), it has begun in the NW (as it did in 1990 and a few other years).

Not all of the open water is due to melt, of course. As I discussed last week in relation to the Southern Beaufort Sea, winds and prevailing currents at this time of year start to fracture the ice and move it around well before much significant melt has begun.

Compare 2016 (above) to 2006 (below), when there was 0.1 mkm2 less overall – with much less ice in Hudson Strait and in the east of Hudson Bay than this year:
masie_all_r10_v01_2006136_4km

Compare to 2011, when there was also 0.1 mkm2 less overall than this year:
masie_all_r10_v01_2011136_4km

It’s important to keep in mind that the intensive feeding season for polar bears is drawing to a close – within another two weeks, most young-of-the-year seals will be in the water feeding and inaccessible to bears.

The only seals on the ice during June and July are predator-savvy adults and subadults that have hauled out to moult and for these seals the rapidly disintegrating ice creates many escape routes. That means that as long as the ice breakup sequence allows polar bears to get their fill of young seals before the end of May, even during early breakup years most bears should be fat enough to survive the coming summer and winter fasts (see more here). So we should expect to see some bears coming ashore within the next two weeks.

Continue reading