Featured Quote #1
“…landfast sea ice [aka shorefast ice] is not currently incorporated into global climate models.”
Ryan J. Galley, Brent G.T. Else, Stephen E.L. Howell, Jennifer V. Lukovich and David G. Barber. 2012. Landfast sea ice conditions in the Canadian Arctic: 1983-2009. Arctic 65(2):133-144. pg. 135, par. 2
Note: This paper (behind a paywall until at least July 2013, one year after publication), describes the mean onset date, breakup date and duration of landfast [shorefast] ice using digital charts generated by the Canadian Ice Service. Landfast ice thickness is not discussed.
Featured Quote #2
“as you can see, the reports of polar bears being forced ashore four weeks early in Churchill were a little premature… Now, with the first gunshots of the summer, we can officially say that sea ice season is done.” [Dated July 29, 2012]
From “Polar Bear Blog – Bear Bangers Return”
Posted on July 29, 2012 by Polar Bear Alley blog author Kelsey Eliasson.
“The blog is usually written from a little cabin 15 miles east of Churchill, Manitoba, Canada at a place called Camp Nanuq. It is a ‘cottage subdivision’ of Churchill – the suburbs. There is power but no running water and a lot of snow.”
Featured Quote #3
Sea ice in the northern Chukchi Sea and western Beaufort Sea…”is thicker and melting slower than usual… First-year ice is 9 to 11 feet [2.7-3.3 meters] thick”. [July 26, 2012]
Said Kathleen Cole, the National Weather Service’s sea ice program leader in Alaska, Thursday July 26, 2012. In a news report by Lisa Demer, Anchorage Daily News, July 27th Titled, “Despite complications, Shell optimistic about Arctic drilling plans”
Featured Quote #4
“Sea ice can be thin enough to avoid detection by satellite sensors but thick enough to stop ships.” Walt Meier, National Snow and Ice Data Center. Aug. 14, 2012.
From this news report: “Fast melt in Canadian Arctic may open Northwest Passage this year” Alaska Dispatch | Aug 14, 2012
The New York Times is reporting that ice melting in a northern Canada waterway that normally remains ice-choked all summer, Parry Channel, may lead to an opening of the famous Northwest Passage this year.
By the first week of August, “some ice was still clinging to the shores of Victoria and Melville Islands but open water otherwise dominated the region,” according to the Times. Parry Channel, in the territory of Nunavuut, runs east to west, connecting Baffin Bay in the east to the Beaufort Sea in the west.
By July 30, ice covered about a third of the channel – far below the median of 79 percent.
Walt Meier of the National Snow and Ice Data Center told the New York Times, however, that while the Parry Channel appeared nearly free of ice, it was not necessarily open to navigation. Sea ice can be thin enough to avoid detection by satellite sensors but thick enough to stop ships.
Featured Quote #5
“We’ve always known that there are dens in there [south of Wapusk Nat. Park]… but not to this extent. We have a fairly large number of denning females in there, equal to or even maybe surpassing Wapusk National Park.” [Aug. 21, Daryll Hedman]
From this news story:
“Polar bear dens found near Manitoba-Ontario border” The Canadian Press Aug 21, 2012 10:26 AM CT
“Manitoba conservation officials have stumbled across a pleasant surprise — a large number of polar bear dens along the Hudson Bay coast near the Ontario boundary.
The dens lie in an area southeast of Wapusk National Park and east of the Nelson River. It’s a region along the southern end of the polar bear’s range and not as well-known as Wapusk, Churchill and other areas to the north.
“We’ve always known that there are dens in there … but not to this extent,” said Daryll Hedman, the regional wildlife manager for northeast Manitoba.
“We have a fairly large number of denning females in there, equal to or even maybe surpassing Wapusk National Park, so it’s fairly exciting news.”
Female polar bears dig the dens in the ground to give birth. The discovery could be a sign that the polar bear population in the area is in good shape, at least for now. The province is beginning a three-year study to get more detail.”
Here is region they are talking about:
Featured Quote #6
In Northwest Greenland (near Thule), Kurt Burnham (of the High Arctic Institute) claims to have seen more bears in one summer than he has in his previous twenty. [Aug. 22, 2012]
From this report: Aug. 22, 2012, The Polar Field Services Newsletter
“It was a big week for wildlife viewing,” wrote Joe Hurley, PFS’ science support manager at the U.S. Thule Air Base in northwestern Greenland. “In addition to the usual musk ox, bird, fox and hare sightings, we seem to be surrounded by polar bears. Kurt Burnham (High Arctic Institute) claims to have seen more bears in one summer than he has in his previous twenty. A number of bears have been witnessed on the local islands and in adjacent valleys. Robin Davies and I came across the bear pictured above on the BMEWS road, approximately 2 miles from the base perimeter.”
Featured Quote #7
“One 17-year-old female from western Hudson Bay with three cubs-of-the-year was handled in November, 1983 when she weighed 99 kg [218 lbs]. The following July she was without cubs, probably pregnant, and weighted 410 kg [910 lbs], a four-fold weight change in eight months.” Ramsay and Stirling 1988:615.
Note this bear was one of 12% of Western Hudson Bay females surveyed between 1980 and 1984 who had triplets. She not only had three cubs but was able to wean them at 1.5 years – in other Canadian populations, 1% or fewer females gave birth to triplets and none weaned their cubs at 1.5 years.
A decline in this spectacular level of cub production for Western Hudson Bay polar bears would put the reproductive characteristics of this population in line with polar bears elsewhere in the Arctic.
[Ramsay and Stirling (1988:624) reported 70% of females with twins and 12% with triplets in 1980-1984, while Derocher and Stirling (1996:1248) reported 71% females with twins and 18% with triplets over the period 1980-1992. Elsewhere in Canada, the rate of triplets was <1%. No other population is known to wean cubs at 1.5 years (Stirling and Lunn 1997:171)]
Ramsay, M. A. and Stirling, I. 1988. Reproductive biology and ecology of female polar bears (Ursus maritimus). Journal of Zoology London 214:601-634. http://onlinelibrary.wiley.com/doi/10.1111/j.1469-7998.1988.tb03762.x/abstract
Derocher, A.E. and Stirling, I. 1996. Aspects of survival in juvenile polar bears. Canadian Journal of Zoology 74:1246-1252. http://www.nrcresearchpress.com/doi/abs/10.1139/z96-138
Stirling, I. and Lunn, N.J. 1997. Environmental fluctuations in arctic marine ecosystems as reflected by variability in reproduction of polar bears and ringed seals. In Ecology of Arctic Environments, Woodin, S.J. and Marquiss, M. (eds), pg. 167-181. Blackwell Science, UK.
Featured Quote #8
“The increase in the Svalbard polar bear population in recent years [1972 vs.1980], with consequently higher abundance of adult bears, may have increased cannibalism and predation upon cubs.” From Larsen (1985:325).
Larsen, T. 1985. Polar bear denning and cub production in Svalbard, Norway. Journal of Wildlife Management 49(2):320-326.
Featured Quote #9
“the lifeblood of most polar bear research is jet fuel needed by helicopters stored in strategically placed caches.” From Derocher and Lynch 2012:107
Next sentence in this paragraph continues…
“I cringe at the thought of my research-related carbon footprint, but the information we collect is vital to the conservation and wise management of the species and their ecosystem.”
Derocher and Lynch. 2012. Polar Bears: A Complete Guide to their Biology and Behavior. Johns Hopkins University Press.
Featured Quote #10
“Nichol’s (1967) climatic reconstructions [western of Hudson Bay, Canada] show that the forest tundra margin was once 300 km farther north and that summer temperatures between 6000 and 3500 years ago were about 3 degrees C warmer than at present. [continues...] A cooling period occurred between 3500 and 1500 years ago, followed by a warming trend (the Medieval Warm Period), which lasted with minor fluctuations until 600 years ago. Cooler conditions have prevailed since that time. Whether we have begun a climatic cooling and are part way into the next glacial epoch, or whether the cooling trends are short term fluctuations remains to be seen.” Dredge 1992:14
Dredge, L.A. 1992. Field Guide to the Churchill region, Manitoba: Glaciations, sea level changes, permafrost landforms, and archaeology of the Churchill and Gillam areas. Geological Survey of Canada Miscellaneous Report 53.
Nichols, H. 1967. Central Canadian palynology and its relevance to Northwestern Europe in the late Quaternary period. Review of Paleobotany and Palynology 2:231-243. http://www.sciencedirect.com/science/article/pii/0034666767901510
Featured Quote #11
From this paragraph in COSEWIC 2008: 29 (quote highlighted in red):
“Derocher et al. (2004) provide a synopsis of possible scenarios [computer modeled predictions] of changes in food availability to polar bears in the contest of climate change, including the potential for climate warming to benefit some subpopulations, at least over the shorter term. This might apply to polar bears at the extreme northern edge of the species’ range (e.g., Viscount Melville Sound, western Lancaster Sound, Norwegian Bay, Kane Basin, and the Arctic Basin)[see map below], where low primary productivity and multi-year sea ice limits densities of and access to ringed seals (Kingsley et al. 1985). Even within areas of relatively close proximity, the impact of climate change might vary substantially. For example, during the period of decreased abundance of polar bears in Western Hudson Bay attributed to impacts of climate change (above, Sections 4.2 and 7.10), there was no observable decline in numbers of bears in Southern Hudson Bay (Section 7.11), although concordant declines in body condition were evident (Obbard et al. 2007). Following a new analysis of mark-recapture data first presented in Kolenosky et al. (1992), researchers of the Government of Ontario reported that abundance of polar bears in Southern Hudson Bay was 641 bears (95% CI 401–881) in 1986 and 681 (95% CI 401–961) in 2005 (Obbard et al. 2007).” [my emphasis - note that multiyear ice has been found to be a limiting factor for density of polar bears, i.e. multiyear ice does not enhance polar bear survival nor is multiyear ice a requirement for polar bear survival. See my discussion of first year and multiyear ice in my previous post here.]
References cited in Featured Quote #11
COSEWIC 2008. COSWIC Assessment and Update Status Report on the Polar Bear Ursus maritimus in Canada. Committee on the Status of Endangered Wildlife in Canada. http://publications.gc.ca/collections/collection_2008/ec/CW69-14-351-2008E.pdf
Derocher, A.E., Lunn, N.J. and I. Stirling. 2004. Polar bears in a warming climate. Integrative and Comparative Biology 44:163-176. http://icb.oxfordjournals.org/content/44/2/163.full.pdf+html
Kolenosky, G.B., Abraham, K.F., and Greenwood, C.J. 1992. Polar bears of southern Hudson Bay. Polar Bear Project, 1984-88, Final Report, Ontario Ministry of Natural Resources, Maple, Ontario.
Kingsley, M. C. S., Stirling, I., and W. Calvert. 1985. The distribution and abundance of seals in the Canadian High Arctic, 1980-1982. Canadian Journal of Fisheries and Aquatic Sciences 42:1189-1210. http://www.nrcresearchpress.com/doi/pdf/10.1139/f85-147
Obbard, M.E., McDonald, T.L., Howe, E.J., Regehr, E.V., and Richardson, E.S. 2007. Trends in abundance and survival for polar bears from Southern Hudson Bay, Canada, 1984-2005. USGS Alaska Science Center, Anchorage, Administrative Report.
[note, above paper appears to be super-ceded by this report:
Obbard, M.E., McDonald, T.L., Howe, E.J., Regehr, E.V., and Richardson, E.S. 2007. Polar bear population status in southern Hudson Bay, Canada. USGS Science Strategy to Support US Fish and Wildlife Service Polar Bear Listing Decision, Administrative Report. [pg. 15, "Abundance estimates"]
Featured Quote #12
From a section titled “Estimation of hunting and natural mortality.” The second paragraph discusses drowning.
“The drowning of bears which drift away with the pack ice is probably an important mortality factor. … We noted that bears were often found close to the edge of the ice. When big icefloes or sections of the pack drift off, bears in that ice will most likely perish.”
The following paragraph is the featured quote [my bold]:
“During the 1967 summer expedition, two dead bears were found in the pack [ice], one by our expedition vessel and another one by “Fortuna”, a sealer trophy hunting in the same region. The bodies had no scars or bullet wounds, and a brief autopsy did not reveal the cause of death. Both bears were about 6 years old, and in fair condition.” Larsen 1970: 24.
Larsen, L. 1970. Norwegian polar bear investigations. Appendix IV in Polar Bears: Proceedings of the 2nd working meeting of the Polar Bear Specialists Group IUCN/SSC, 2-4 February, 1970, Morges, Switzerland, pg. 21-33. Gland, Switzerland and Cambridge UK, IUCN. [a summary of the 1st meeting is appended to this report but this fact is not indicated in the title]
Featured Quote #13
Following a paragraph that discusses “behavioural studies on Cape Churchill and the Manitoba coast,” specifically a “marked segregation of the polar bear population by sex and age as the bears return to land in July and August,” there is this paragraph [featured quote in bold]:
“Segregation by sex and age is apparently reinforced by intraspecific fighting. During tagging operations in August, 1969, [in W. Hudson Bay] six bears were observed with fresh wounds, and an adult male was found near the coast devouring an adult female and two cubs he had apparently killed the previous day. Data from bears captured in James Bay indicate that adult males fight during April and May, though during August-October many adult males were observed moving or resting together and even touching without exhibiting aggressive behaviour.”
Jonkel, C. 1970. The present status of polar bear research in Canada. Appendix I in Polar Bears: Proceedings of the 2nd working meeting of the Polar Bear Specialists Group IUCN/SSC, 2-4 February, 1970, Morges, Switzerland, pg. 8-11. Gland, Switzerland and Cambridge UK, IUCN.
Featured Quote #14
“There is currently a lot of variability in how the subpopulations (of polar bear) are doing,” Regehr said. “The media perception that they are all doing terrible is not accurate.” Eric Regehr, US Fish & Wildlife polar bear biologist, Oct. 9 2012 interview.
From this interview at Alaska Dispatch: How many polar bears live in the Arctic? Jill Burke, Oct 09, 2012
Featured Quote #15
“From these data, it is clear that the number of bears other than just pregnant females that use dens regularly during winter to conserve energy during cold weather is much larger than is generally apparent from the literature.” Van de Velde et al. 2003:195.
From a paper (abstract below) that presents data collected through interviews with Inuit hunters of Pelly Bay by Father Franz Van de Velde (now deceased), between 1937-1965 and 1968-69, which I came across while researching a previous post here.
Van de Velde (OMI), F., Stirling, I. and Richardson, E. 2003. Polar bear (Ursus maritimus) denning in the area of the Simpson Peninsula, Nunavut. Arctic 56:191-197. http://arctic.synergiesprairies.ca/arctic/index.php/arctic/article/view/615
Featured Quote #16
“in the Canadian Arctic, ice cover in June and November showed a step change in the mid-1990s, with little reduction before that. There was a similar step change in northern Hudson Bay.” Gaston et al. 2012 in press, see fig. 1 below.
While it is true, as Gaston et al. (2nd to last page) state, that “ice breakup in Hudson Bay in springs of 2010 and 2011 were the earliest on record” [i.e. since 1979], they do not mention the fact that breakup in 2009 appears to have been the latest on record. As far as I have been able to determine, no one else has published that data either. See previous posts here and here.
Gaston, A.J., Smith, P.A. and Provencher, J.F. in press. Discontinuous change in ice cover in Hudson Bay in the 1990s and some consequences for marine birds and their prey. ICES Journal of Marine Science doi:10.1093/icesjms/fss040 http://icesjms.oxfordjournals.org/content/69/7/1218.short
Featured Quote #17
“This whole season has been about a week ahead of last year so it is not a real surprise that the bay [Hudson Bay] froze about a week earlier than last year. Yesterday, we watched the mass exodus of polar bears out onto the sea ice. Most of the day consisted of yellow bear butts wobbling and weaving out towards the floe edge.” Kelsey Eliasson, 2012/11/14, near Churchill, Manitoba
Read the whole thing, it’s fascinating!
Featured Quote #18
“Sea ice coverage varies greatly from one year to the next and from one regional location to the next. So, one summer may find thick impenetrable ice in a specific region—when the summer before, large areas were completely accessible.” Walt Meier, research scientist at NSIDC, Nov. 2, 2012.
Quote is from this Alaska Dispatch article: “Melting Arctic may lure investors but is development economically viable?” Laura Naranjo Nov 02, 2012 (which is said to be a reprint from the NSIDC Icelights blog)
Featured Quote #19
“The NB [Northern Beaufort Sea] polar bear population appears to have been stable or possibly increasing slightly during the period of our study. This suggests that ice conditions have remained suitable and similar for feeding in summer and fall during most years and that the traditional and legal Inuvialuit harvest has not exceeded sustainable levels.”
From the abstract of this paper:
Stirling, I., McDonald, T. L., Richardson, E. S., Regehr, E. V., and Amstrup, S. C. 2011. Polar bear population status in the northern Beaufort Sea, Canada, 1971–2006. Ecological Applications 21:859–876. http://www.esajournals.org/doi/abs/10.1890/10-0849.1
Abstract [quoted portion in italics]
“Polar bears (Ursus maritimus) of the northern Beaufort Sea (NB) population occur on the perimeter of the polar basin adjacent to the northwestern islands of the Canadian Arctic Archipelago. Sea ice converges on the islands through most of the year. We used open-population capture–recapture models to estimate population size and vital rates of polar bears between 1971 and 2006 to: (1) assess relationships between survival, sex and age, and time period; (2) evaluate the long-term importance of sea ice quality and availability in relation to climate warming; and (3) note future management and conservation concerns. The highest-ranking models suggested that survival of polar bears varied by age class and with changes in the sea ice habitat. Model-averaged estimates of survival (which include harvest mortality) for senescent adults ranged from 0.37 to 0.62, from 0.22 to 0.68 for cubs of the year (COY) and yearlings, and from 0.77 to 0.92 for 2–4 year-olds and adults. Horvtiz-Thompson (HT) estimates of population size were not significantly different among the decades of our study. The population size estimated for the 2000s was 980 ± 155 (mean and 95% CI). These estimates apply primarily to that segment of the NB population residing west and south of Banks Island. The NB polar bear population appears to have been stable or possibly increasing slightly during the period of our study. This suggests that ice conditions have remained suitable and similar for feeding in summer and fall during most years and that the traditional and legal Inuvialuit harvest has not exceeded sustainable levels. However, the amount of ice remaining in the study area at the end of summer, and the proportion that continues to lie over the biologically productive continental shelf (< 300 m water depth) has declined over the 35-year period of this study. If the climate continues to warm as predicted, we predict that the polar bear population in the northern Beaufort Sea will eventually decline. Management and conservation practices for polar bears in relation to both aboriginal harvesting and offshore industrial activity will need to adapt.”
And from the section titled “population size and trend” (pg. 872-873), the authors note:
“Although our averaged estimates of population size did not differ significantly over the three decades [1970s, 1980s, and 2000s], other evidence suggest that the population could have gradually increased. Stirling (2002) reported in the 1970s, polar bears in the Canadian sector of the Beaufort Sea were recovering from a period of overharvest that ceased only when quotas were established in Canada in 1968 and the Marine Mammal Protection Act (1972) stopped aerial hunting in Alaska.
If, as our observations suggest, the population estimate for 2006 is biased low, the estimates of ~1200-1300 in 2004 and 2005 may more accurately reflect the current number of polar bears in NB. Such an estimate suggests the possibility of some continued population growth through the end of our study.” [my emphasis]
Featured Quote #20
“Seven of the last 10 years have produced above-average freezing in the waters west of Alaska, Cole said. Last year, seasonal sea-ice cover and thickness in the Bering Sea were higher than any time since record-keeping began four decades ago.” Kathleen Cole, Alaska National Weather Service, Dec. 6, 2012.
From this news article:
Mariners dodging more free-floating ice in Arctic waters off Alaska by Alex DeMarban Dec 06, 2012
Featured Quote #21
“The environmental movement has never had a higher-profile spokesmodel than Ursus maritimus. Every discussion about global warming has to include a mention of polar bears; every article about the human disregard for nature has to feature a photograph of a sad-looking bear on a tiny speck of ice.” Unger 2012:30.
From this magazine article
Unger, Z. 2012. The truth about polar bears. Canadian Geographic December:28-42. http://www.canadiangeographic.ca/magazine/dec12/polar_bears.asp
For a couple of examples of this, see this recent Guardian article by Adam Corner (Dec 13 2012) http://www.guardian.co.uk/sustainable-business/blog/internal-attitudes-climate-change-matter which features a lonely-looking polar bear on an iceberg (see below).
Compare and contrast this with a similar photo taken in the Beaufort Sea by Amanda Byrd in 2004, which has become an iconic message for some folks.
See the description of the expedition here, with the “interesting photo” included. PB on an iceberg_Amanda Byrd photo report 2004 Dispatch 2
H/T Barry Woods
Featured Quote #22
“The ESA was not enacted to protect healthy animal populations. Despite this fact, the NMFS continues the federal government’s misguided policy to list healthy species based mostly on speculated impacts from future climate change, adding additional regulatory burdens and costs upon the State of Alaska and its communities.” Alaska Governor Sean Parnell, Dec. 21 2012.
From this article: “Ringed, Bearded Seals Listed Under Endangered Species Act Due Partially To Climate Change Concerns.” Dan Joling, Dec. 21, 2012. Huffington Post
which says also that:
“The NOAA Fisheries decision affects four subspecies of ringed seals around the world. Arctic Ocean seals off Alaska’s coast and seals on the Okhotsk and Baltic seas were listed as threatened…The listing covered two subspecies of bearded seals: the Beringia population, which includes Alaska, and bearded seals in the Sea of Okhotsk.”
This despite the fact (discussed earlier, in Featured Quote #20 above), that seven of the last 10 years had above-average sea ice in the Bering Sea (which is home to at about half of the bearded and ringed seals of concern to the US). Last year broke the record for sea ice extent in the Bering Sea and so far, this year has well above-average extent as well.
Some seal facts: According to the last census, there were more than 278,000 bearded seals in the western Arctic (Bering, Chukchi, Beaufort, Okhotsk and East Siberian Seas) (Cameron et al. 2010). Bearded seals in the Sea of Okhotsk routinely use beach haulouts in summer and fall after the sea ice melts. (Cameron et al. 2010:13). Bearded seals are found throughout the arctic (i.e. the are “circumpolar” in distribution).
Ringed seals live in the same areas of the western Arctic as bearded seals, and their total population has been estimated at 3-4 million individuals (Kelly et al. 2010). Like the bearded seal, ringed seals have a circumpolar distribution.
Cameron, M. F., Bengtson, J. L., Boveng, J. K., Jansen, J. K., Kelly, B. P., Dahle, S. P., Logerwell, E. A., Overland, J. E., Sabine, C. L., Waring, G. T. and Wilder, J. M. 2010. Status review of the bearded (Erignatha barbatus). NOAA Technical Memorandum NMFS-AFSC-211.
Kelly, B. P., Bengtson, J. L., Boveng, P. L., Cameron, M. F., Dahle, S. P., Jansen, J. K., Logerwell, E. A., Overland, J. E., Sabine, C. L., Waring, G. T. and Wilder, J. M. 2010. Status review of the ringed seal (Phoca hispida). NOAA Technical Memorandum NMFS-AFSC-212.
Featured Quote #23
“The polar bear is the only bear, and probably one of the only large carnivores that still occurs throughout most of its original range.” Derocher et al. 1998:37.
From this Polar Bear Specialist Group (IUCN/SSC) report:
Derocher, A., Garner, G.W., Lunn, N.J., and Wiig, Ø. (eds.) 1998. Polar Bears: Proceedings of the 12th meeting of the Polar Bear Specialists Group IUCN/SSC, 3-7 February, 1997, Oslo, Norway. Gland, Switzerland and Cambridge UK, IUCN. http://pbsg.npolar.no/en/meetings/
Featured Quote #24
“If you have ever wondered what if feels like to come face to face with a polar bear, check out this video by Scottish wildlife cameraman Gordon Buchanan.” Levon Sevunts (Jan 10, 2013) Alaska Dispatch “Attacking polar bear gives Arctic wildlife documentary filmmaker scare of a lifetime (+VIDEO)”
From this Alaska Dispatch report (with video):
Attacking polar bear gives Arctic wildlife documentary filmmaker scare of a lifetime (+VIDEO)
He was shooting a documentary about a family of polar bears in Norway’s Svalbard Arctic archipelago when he attracted the attention of a female bear. Luckily for him, Buchanan was inside a protective pod, an “ice cube” made of reinforced steel and Plexiglas.
For forty minutes the bear clawed and chomped at the glass, rattled the cage, systematically looking for weak points as she tried to get to Buchanan, who amazingly kept his composure while providing play-by-play commentary of the assault.
Buchanan said his crew had set up the protective pod near some seal breathing holes, hoping to film the bear as she hunted seals. Instead, the bear was attracted by the unusual human odour emanating from the glass cage. Fortunately for Buchanan it withstood the bear’s sustained assault.
See original article for more.
Featured Quote #25
“Researchers have seldom reported use of shelter dens in winter for polar bears, probably because of the difficulty of making observations during winter darkness. Only recently has satellite telemetry made observations of use of shelter dens in winter possible.” Ferguson et al. 2000:1125.
From this paper:
Ferguson, S. H., Taylor, M. K., Rosing-Asvid, A., Born, E.W. and F. Messier 2000. Relationships between denning of polar bears and conditions of sea ice. Journal of Mammalogy 81:1118-1127.
Featured Quote #26
“Polar bears are capable of entering a hibernationlike state at any time of year within 7-10 days after food is removed (Derocher et al. 1990), an adaptation not found among terrestrial bears.” Ferguson et al. 2000:1119.
From this paper:
Ferguson, S. H., Taylor, M. K., Rosing-Asvid, A., Born, E.W. and F. Messier 2000. Relationships between denning of polar bears and conditions of sea ice. Journal of Mammalogy 81:1118-1127.
Featured Quote #27
“In villages across the Arctic, Inuit are reporting an invasion. Polar bears, once rare, are now strolling the streets, peeking in windows, killing dogs – even stalking kids. No place has been more menaced than Arviat.” Jake MacDonald: “Besieged by Bears,” Jan/Feb 2013 issue of Uphere Magazine.
From the headline of this story in Uphere Magazine, Jan/Feb 2013 issue:
Besieged by bears
January/February 2013 [may be from 2007 - I'm waiting for an answer from the publisher]
In villages across the Arctic, Inuit are reporting an invasion. Polar bears, once rare, are now strolling the streets, peeking in windows, killing dogs – even stalking kids. No place has been more menaced than Arviat. By Jake MacDonald
When Darryl Baker was growing up in Arviat, he didn’t know much about polar bears. “You could go all summer up and down the Hudson Bay coast in a boat and never see one. When the elders camped out, they would tie out a dog to warn them if a bear was coming. But us young guys didn’t bother with that, because we never saw bears.”
He recalls that he didn’t know much about anything else, either. His father was a white man who took off and left him to be raised by his Inuit mother and various Inuit uncles and grandfathers. “I wanted to be a hunter and trapper like them, but I was very stupid and I nearly died, many times. I would swamp the boat at sea, or get whited out, or get lost on the tundra. I bought a GPS, thinking I could go anywhere now. But the elders just smiled. ‘Will that little thing teach you where the thin ice is?’”
The first time Darryl Baker saw a polar bear, he was on his snowmachine, checking his fox traps. A snowdrift alongside the trail reared up and became a large polar bear. “I took off out of there,” he said. “But it was very scary because my snowmachine wasn’t running good and I was afraid I was going to have to walk back to town with that polar bear on my trail.”
He wanted to emulate his Inuit mentors, so he got himself some sled dogs. But he says polar bears are a constant problem for dog mushers. “There’s lots of polar bears now. They come right into town, and they hate dogs. A couple of years ago my neighbour phoned me one morning and said, ‘there’s a big polar bear coming down the street and he looks like he’s in a bad mood.’ The bear was heading right for my dogs. I opened the kitchen window and fired a shot to scare it off but it ignored me and killed one of my dogs with one slap. So I shot the bear.”
The CBC interviewed him, and qallunaat – white people – criticized him on the web site. “People were saying a polar bear is more valuable than a sled dog. Well, I work hard and I spend a lot of money on my dogs. A good dog is worth from two thousand to five thousand dollars. They said you should put your dogs in a ‘safe location.’ We don’t have safe locations. The bears walk right into the hamlet. Am I supposed to just stand there and watch when a bear starts killing my dogs?”
Conflicts with polar bears are becoming a problem across Nunavut, and Arviat is one of the hotspots. Arviat (which translates as “place of the bowhead whale”) is the southernmost community in mainland Nunavut, and one of the most traditional. Its population is about 90 per cent Inuit, and Inuktitut is the primary language. Groceries are expensive and “country food,” like caribou and fish, is the main source of protein. Many Inuit hunters and trappers are strengthening their cultural heritage by keeping dog teams, but in Arviat and other communities across the Arctic, bears make it difficult to be a dog owner. “And it’s not just dogs you have to worry about,” says Kukik Baker, Darryl’s wife. “Kids are in danger too. We’re afraid to let them walk home from school, or even play outside.”
In 2012, the Nunavut government conducted a long-awaited census of western Hudson Bay polar bears and came up with 1,013 animals, or about twice as many as the number projected by environment Canada. Dr. Mitch Taylor, a lifelong polar bear scientist who, at times, has been ostracized by his peers for insisting that polar bear populations are generally stable, took some satisfaction from the results. “The Inuit were right. There aren’t just a few more bears. There are a hell of a lot more bears.” [my bold]
The study, however, was cold comfort to the people of Arviat. Scientists might continue to squabble about survey results, but the Arviarmiut are certain they’re having far more bear encounters than ever before, and no one seems to know what to do about it.
See the rest of the story here [h/t to reader Dave]
Featured Quote #28
“Cub survival [in grizzly bears] is a wild card in the bear world. A study done in Denali National Park and Preserve found 65 percent of Denali cubs die. Other research would indicate that’s near normal in the wilds of the 49th state.” Craig Medred, Alaska Dispatch Jan. 28, 2013.
Remember that when you hear folks discussing polar bear cub mortality numbers as if such levels are unnatural. The truth is, cub mortality in bears is naturally high.
From a recent story about a new survey of Kenai Peninsula, Alaska grizzly bears numbers. I’ve added a map of Alaska with both the Kenai Peninsula (near Anchorage) and Denali National Park (in Interior Alaska) marked. An excerpt is below.
Kenai grizzly population is 624 — but don’t bet your life on it
Craig Medred, Alaska Dispatch Jan. 28, 2013.
Federal scientists have concluded there are 624 grizzly bears on Alaska’s Kenai Peninsula, or at least they believe there were 624 bears there at some point in 2010. Maybe.
The problem, they confess, is that grizzly bears are hard to count. They roam vast home ranges. They are often hidden from view in alder thickets. Anti-social by evolutionary design, they do not gather into bands or easily-counted herds. And, if all that weren’t enough, their populations tend toward significant seasonal variability.
Reaching that 624 bear took two years of genetic fingerprinting of 11,175 samples of bear hair from 145 barbed-wire hair traps scattered throughout 70 percent of the bear habitat on the Kenai Peninsula, south of Alaska’s largest city. It is estimated to include 200 boars, 200 sows, and 224 cubs — and that’s just one of the places things begin to get complicated.
Few cubs survive
Cub survival is a wild card in the bear world. A study done in Denali National Park and Preserve found 65 percent of Denali cubs die. Other research would indicate that’s near normal in the wilds of the 49th state.
Applying a 65 percent mortality rate for cubs in the study based on hair samples collected over five days in June 2010 could result in a bear population as low as 480 bears by fall of that year. And then, too, there is the variability around the 624 number itself. It’s the highest probability point in a population range from 504 bears to 772 bears, cubs included.
“It’s challenging to study bears,” said Gino Del Frate, an Alaska Department of Fish and Game biologist, who nearly 15 years ago estimated the Kenai population at 140 to 280 grizzlies. At the time, there were concerns the Kenai bears might be threatened by extinction. The bears appeared few in number and largely cut off from the rest of Alaska by the fjord-like waters of Turnagain Arm.
Fears of an isolated, inbred bear population have fallen over the years as genetic studies found what appears to be only a small bottleneck in gene mixing between Kenai and mainland bears. Tracking radio-collared bears has demonstrated the Arm apparently doesn’t pose a large impediment to movement.
The bears had once been thought to need the isthmus of land near the community of Portage that connects the Kenai to the rest of Alaska, but it appears that Kenai bears — being good swimmers and unafraid of the legendary, foot-sucking mud of the Arm — can cross to the mainland elsewhere.
Concerns about a vulnerable population of Kenai grizzlies did, however, lead to tight restrictions on Kenai Peninsula hunting in the years since Del Frate’s population estimate, and there are indications bear numbers might have increased despite a large number of shootings in defense of life and property (DLP). It is legal for Alaskans to shoot bears in self-defense, and in some years a lot of bears have died that way on the Kenai. There were about 40 DLP kills in 2008, for instance.
A kill of that size would have triggered a decline in the grizzly population then estimated between 200 and 350 bears, but state officials said they saw no such thing. If anything, it appears bear numbers were tracking steadily upward. Alaska Department of Fish and Game biologist Sean Farley, in a yet unpublished report from 2011 on research dating back to the 1990s, estimated there could be more than 1,000 bears on the Kenai Peninsula.
Some say too many grizzlies
Conflicts between humans and what is publicly perceived to be a growing bear population has even led some to contend there are now too many grizzlies on the Kenai.
The new population number — from the paper authored by researchers John Morton of the Kenai National Wildlife Refuge, Gregory Hayward of the Chugach National Forest, and others — would argue otherwise.
“Our estimate of the Kenai brown bear population is generally consistent with estimates of brown bear density in Interior, rather than coastal Alaska,” wrote Morton, the lead author. The Interior, with its food-short ecosystem due to extremely cold winters and a limited growing season — is not known for supporting vast populations of bears. With bountiful runs of salmon and a warmer climate, the Kenai would at first blush appear more like the Alaska Peninsula or the state’s Panhandle, where previous studies have found bear densities four to 10 times as great as that calculated for the Kenai.
Read the rest here.
See original Kenai Grizzly Report here
Featured Quote #29
“…in the spring of 1974, when ringed seal pups first became scarce, we capture two very thin lone adult female polar bears that had nursed recently, from which we deduced they had already lost their litters. A third emaciated female was accompanied by two cubs which were so thin that one could barely walk. We have not seen females with cubs in this condition in the Beaufort Sea, or elsewhere in the Arctic, before or since.” Stirling and Lunn 1997:177 regarding studies in the Beaufort Sea.
This comment related to conditions that resulted from a cold winter and heavy sea ice, not warming and early ice breakup. And it was not Western Hudson Bay but the southern shore of the Northern Beaufort (Canada) and it caused polar bear numbers to plummet, see previous posts here and here. No cries of “feed the starving polar bears” then – or in the 1980s or the 1990s, when it happened again. It seems polar bear deaths by starvation only matter when the cause can be attributed to global warming.
From this scientific paper
Stirling, I. and Lunn, N.J. 1997. Environmental fluctuations in arctic marine ecosystems as reflected by variability in reproduction of polar bears and ringed seals. In Ecology of Arctic Environments, Woodin, S.J. and Marquiss, M. (eds), pg. 167-181. Blackwell Science, UK.
Featured Quote #30 [posted Feb. 17, 2013]
Is it getting warmer at the North Pole? From soundings and meteorological tests taken by the Soviet explorers who returned this week to Murmansk, Russia’s sole ice-free Arctic port, it was concluded that near Polar temperatures are on an average six degrees higher than those registered by Nansen 40 years ago [in 1900]. Ice Measurements were on an average only 61/2 feet against 91/2 to 13 feet. The Townsville Daily Bulletin, Feb. 23, 1940.
From this short newspaper article published in The Townsville Daily Bulletin, Queensland, Australia on February 23, 1940 [via Trove digitized newspapers]
THE NORTH POLE.
Is it Getting Warmer.
(From a Special Correspondent. By Air Mail.)
BUNDABERG, February 22.
Is it getting warmer at the North Pole? From soundings and meteoro- logical tests taken by the Soviet ex- plorers who returned this week to Murmansk, Russia’s sole ice-free Arctic port, it was concluded that near Polar temperatures are on an average six degrees higher than those registered by Nansen 40 years ago. Ice measurements were on an average only 6½ feet against from 9¼ to 13 feet.
The return of the Soviet icebreaker Sedoff brought to a close a Polar expedition, involuntarily undertaken which led to important discoveries. For 2½ years she had drifted while trapped in Polar ice. Fifteen men volunteered to stay on board the Sedoff until relief came. In the drift to the north-west these men passed nearer to the North Pole than any other ship. Their highest latitude registered was 86 degrees 56min. North. They discovered by soundings a near Polar sea pocket, 17,260 feet deep. Such a pocket had hitherto been unsuspected in the Polar Sea.
h/t to S. Goddard
Featured Quote #31 posted Feb. 22, 2013
“While we are here, it’s probably time to admit that polar bears have been fed and baited in Churchill for forty years now. In 1972, Fred Bruemmer, one of the greatest environmentalists/photographers went out to Cape Churchill and poured bacon fat around the tower out there. BBC poured seal oil on the cage (as many did) to make the 1982 documentary Polar Bear Alert which in turn created polar bear tourism.” Kelsey Eliasson, PolarBearAlley, Feb. 5, 2013.
From a blog post Feb 5, 2013 at PolarBearAlley:
Let’s Feed The Bears (Some More) Posted on February 5, 2013
So, I have seen this idea come up here and there… most recently, it started with Robert Buchanan from Polar Bears International and now with one of his researchers, Andrew Derocher. The idea is to feed polar bears (specifically Churchill’s bears) while they are on land to help offset the decline in sea ice. Offhand it seems insane; after you have lived in the north for a while, insane seems intriguing.
Incidentally, this idea first came up back in the day when Brian Ladoon suggested that Churchill should hang beluga whale carcasses on the beach by the Town Complex so that people could watch polar bears for free. Pretty similar to the industry growing in Kaktovik, Alaska today… For all his warts, Ladoon is a visionary. So there’s a bit of Churchill lore for you… true or not, ha.
This blog stems from an article and paper by Derocher et al about planning now for polar bear’s future (a computer model future, of course… as if there is any other these days, Hal).
To quote Derocher, “The management options for northern communities like Churchill would range from doing nothing, to feeding the bears, moving them somewhere else or euthanizing them.” Oh my!
Read the rest of this great story here.
Featured Quote #32
“Churchill’s bears are among the most poked, prodded and scrutinized creatures in the world. They are chased by helicopter or tundra buggy, and drugged so that researchers can analyze their blood, their bodies and their teeth. An estimated 80 per cent of Churchill’s bears have encountered researchers – sometimes more than once.” Wente, Globe and Mail, Feb. 23, 2013.
From this column in the Globe and Mail (Toronto, Canada) by Margaret Wente (Feb. 23, 2013):
How to save the polar bears: Leave them alone!
Here’s some news you won’t hear from Dr. Derocher. The polar-bear population is not declining. In fact, it’s much bigger than it was 40 years ago, when a global hunting ban was introduced. After dwindling to a few thousand, the number of polar bears has rebounded to 20,000 or 25,000 today.
“This is essentially a heartening fact, but nobody knows it,” says Zac Unger, a California writer who planned to write a book on the end of the polar bears. Instead, he wound up writing a book about the loss of scientific integrity. It’s called Never Look a Polar Bear in the Eye.
“I set out to write this mournful elegy for the polar bear, and then I got there and the bears were doing better than I’d thought – which was great news for the bears but terrible for my book,” Mr. Unger told me.
Instead of emaciated bears, what he found was a vigorous scientific debate between catastrophists and other scientists who are far more optimistic. But the public only hears one side. Mr. Unger found that the catastrophists have abandoned proper science for polemics – what he calls science by sound bite. “When you say that the polar bears are going to be dead by a certain date, you are making a political point, not a scientific one,” he says. “I don’t think they’re dishonest people, but any time they have a choice or an assumption to make, they choose the worst-case scenario.”
The other day I had a chat with Kelsey Eliasson, a polar bear guide who lives in Churchill and writes a blog about the bears. “I’ve done 14 bear seasons,” he told me. “There’ve been some good years and some really bad years. But nobody is seeing a constant decline.”
Mr. Eliasson is skeptical of doom-and-gloom scenarios based on computer models – on which scientists such as Dr. Derocher rely heavily. “There is a widespread belief in the North these days that researchers and NGOs have become more interested in media face-time than actual polar bear research,” he says. “They are super nice guys. I had incredible respect for them, but now I’m blogging against them. I just feel like they’re lost.”
Churchill’s bears are among the most poked, prodded and scrutinized creatures in the world. They are chased by helicopter or tundra buggy, and drugged so that researchers can analyze their blood, their bodies and their teeth. An estimated 80 per cent of Churchill’s bears have encountered researchers – sometimes more than once. In Mr. Eliasson’s view, the best way we can help the bears is to stop harassing them. “Declare a five-year moratorium,” he says. “Leave them alone. Everyone around here would be in favour of that.”
Mr. Unger has another suggestion for polar bear researchers. Stop doing politics and get back to doing science, which is by its very nature complicated and uncertain. Of course, the headlines might die down. But the alternative is to risk being utterly discredited. And that would not be good for polar bears, scientists or anybody else.
Featured Quote #33 published March 5, 2013
“A move to up-list polar bears to CITES Appendix I would put polar bears in a category reserved for the world’s most immediately endangered species like tigers, gorillas, jaguars, rhinos and panda bears, which are threatened with extinction.” Nunatsiaq News, March 1, 2013.
From this news story: “Nunavut will fight against trade ban at CITES meeting” NUNATSIAQ NEWS, March 01, 2013
Nunavut’s environment minister plans to travel to Bangkok next week for the CITES meeting to make sure that a move to put trade restrictions on polar bear trophies is not adopted.
Nunavut stands behind its sustainable management of polar bears, said James Arreak, Nunavut’s minister responsible for the Department of Environment, in the legislative assembly Feb. 28.
“As I reported during our last sitting, the United States has once again submitted a proposal to CITES to have the polar bear up-listed from Appendix II to Appendix I,” Arreak said in a minister’s statement.
CITES Appendix II lists species that are not necessarily now threatened with extinction, but that may become so unless trade is closely controlled.
A move to up-list polar bears to CITES Appendix I would put polar bears in a category reserved for the world’s most immediately endangered species like tigers, gorillas, jaguars, rhinos and panda bears, which are threatened with extinction. Such an up-listing would ban all international trade in polar bear products. [my bold]
The proposal will be considered and voted upon at the upcoming CITES conference of the parties next week.
“We do not support this proposal, which has no rational basis,” Arreak said.
Many of the world’s leading wildlife conservation organizations, including the World Wildlife Fund, Polar Bears International and Traffic, have joined the fight to oppose this proposal, Arreak said.
Those groups are in agreement that polar bears do not meet the necessary criteria for an Appendix I listing.
Full story here.
Featured Quote #34 March 6, 2013
[at the CITES conference, where delegates are debating the US proposal to uplist the polar bear to Appendix I ] “A controversial compromise from the EU was tabled on Tuesday, asking Canada to simply report export numbers, but was shouted down, with a final vote expected Wednesday. If it passes, a 90-day clock will start after which it will be illegal to export polar bear parts, although the domestic hunt would continue.” Joseph Brean, National Post, March 6, 2013
From this article: “International conference debates fate of endangered species” By Joseph Brean | 13/03/06 7:14 PM ET
Polar Bear (Ursus Maritimus)
Russia and the United States are not famously cooperative. But a joint proposal to add the polar bear to the list of species who are so endangered that international trade in their parts is banned has caught the attention of the conference, not least the Canadian delegation, who oppose it vigorously. Canada is the source of pretty much all the legal international trade in polar bear pelts. Russia, in which bears are commonly poached and sold with bogus Canadian papers, previously opposed this same move by the U.S. in 2010, but has now come around to the American view that urgent protection is needed.
The Inuit oppose this as a threat to their tourism industry, in which hunting permits for polar bears bring in $20,000 each, and pelts can be sold for $5,000 or more. In all, around 600 bears are taken each year, out of a Canadian population of perhaps 15,000, in 19 population groups. Terry Audla, head of Inuit Tapiriit Kanatami, told Reuters his people have been “very active participants in the management and when it comes to the harvest of bears, it’s based on sustainable levels that would not in any way (have) an impact on the populations and the health of the populations.”
The CITES secretariat also opposes the American proposal, and recommends polar bears stay in the second-tier of protection, with only licensed trade permitted, because there is “insufficient evidence to show that the species has undergone a marked decline in the population size in the wild.”
Even the World Wildlife Fund opposes the proposal, along with other environmental groups, as the threat of hunting is small compared to that of reduced sea ice due to climate change. A controversial compromise from the EU was tabled on Tuesday, asking Canada to simply report export numbers, but was shouted down, with a final vote expected Wednesday. If it passes, a 90-day clock will start after which it will be illegal to export polar bear parts, although the domestic hunt would continue
Read the rest here (other species discussed)
Featured Quote #35 posted March 7, 2013
“The harvest [of polar bears] from the Chukchi/Bering Sea population continues to decline. The 2009 Chukchi Sea harvest [36 bears] was the lowest recorded since 1980/1981, the first year for which we have reliable data.”
USFWS Polar Bear News 2010, pg. 14.
From this US Fish and Wildlife Service document, on page 14: Polar Bear News 2010
Featured Quote #36 posted March 12, 2013
“Up until the present , the numbers of seals and bears in relation to the marine ecosystem have been regarded as being fairly static. This [mortality event of 1974/75 due to cold] is the first time that major changes in numbers and reproductive parameters caused by natural influences have been documented in populations of arctic seals and polar bears.” (Stirling et al. 1979:52, in PBSG 1980)
From the 1979 Polar Bear Specialist Group meeting report, pg. 52, authored by Ian Stirling and colleagues on behalf of Canada:
However, it was apparent from the studies of both polar bears and seals that their populations had undergone marked declines in numbers, productivity, and survival of young in 1974 and 1975. The decline apparently occurred because of natural causes that are not completely understood.
Up until the present, the numbers of seals and bears in relation to the marine ecosystem have been regarded as being fairly static. This is the first time that major changes in numbers and reproductive parameters caused by natural influences have been documented in populations of arctic seals and polar bears.
PBSG (“Anonymous”). 1980. Polar Bears: Proceedings of the 7th meeting of the Polar Bear Specialists Group IUCN/SSC, 30 January-1 February, 1979, Copenhagen, Denmark. Gland, Switzerland and Cambridge UK, IUCN. http://pbsg.npolar.no/en/meetings/
Featured Quote #37 posted April 20, 2013
“Female polar bears in the Beaufort Sea produced only ~0.40 cub/year, whereas in the Hudson Bay area [western HB] they produced up to 0.90 cub/year at the time those studies were conducted (Derocher and Stirling 1992). Reproductive rates in most other areas appear to be more similar to those in the Beaufort Sea than in Hudson Bay.” (Amstrup 2003:600)
From this document:
Amstrup, S.C. 2003. Polar bear (Ursus maritimus). In Wild Mammals of North America, G.A. Feldhamer, B.C. Thompson and J.A. Chapman (eds), pg. 587-610. Johns Hopkins University Press, Baltimore.
Derocher, A.E. and Stirling, I. 1992. The population dynamics of polar bears in western Hudson Bay. Pg. 1150-59. In D.R. McCullough and R.H. Barrett, eds. Wildlife 2001: Populations. Elsevier, Amsterdam. http://link.springer.com/chapter/10.1007%2F978-94-011-2868-1_88
Abstract for Derocher and Stirling 1992
Reproductive output of polar bears in western Hudson Bay declined through the 1980’s from higher levels in the 1960’s and 1970’s. Age of first reproduction increased slightly and the rate of litter production declined from 0.45 to 0.35 litters/female/year over the study, indicating that the reproductive interval had increased. Recruitment of cubs to autumn decreased from 0.71 to 0.53 cubs/female/year. Cub mortality increased from the early to late 1980’s. Litter size did not show any significant trend or significant annual variation due to an increase in loss of the whole litter. Mean body weights of females with cubs in the spring and autumn declined significantly. Weights of cubs in the spring did not decline, although weights of both female and male cubs declined over the study. The population is approximately 60% female, possibly due to the sex-biased harvest. Although estimates of population size are not available from the whole period over which we have weight and reproductive data, the changes in reproduction, weight, and cub mortality are consistent with the predictions of a densitydependent response to increasing population size. [my bold]
Featured Quote #38 posted April 25, 2013
“most of the long-distance swimming events that we identified involved bears swimming from unconsolidated sea ice to the main pack ice or to land.” Pagano et al. (2012).
From this study on polar bear swimming prowess:
Pagano, A.M., Durner, G.M., Amstrup, S.C., Simac, K.S. and York, G.S. 2012. Long-distance swimming by polar bears (Ursus maritimus) of the southern Beaufort Sea during years of extensive open water. Canadian Journal of Zoology 90: 663-676.
Tip: See the excellent summary of this study from the NIPCC (12 June 2012), excerpt below [my bold, quote above in red]:
Pagano and colleagues calculated the mean distance between the mainland coast and the sea ice edge at the end of September for each year of the study period. This distance varied from a low of about 200 km (achieved in 2005, 2006, and 2009) and a high of about 430 km (achieved in 2008). Mean distance from the shore to the ice in 2004 was about 300 km and in 2007, it was about 380 km. Each of these measurements varied somewhat depending on the configuration of the shoreline, but in 2008 the ice edge was definitely the furthest away than in all other years back to 1979. However, the largest number of long-distance swimming events took place in 2009, when the ice edge in this region was about the same distance offshore as in 2005 and 2006.
The longest swim was recorded in late August/early September of 2008 at a point where the sea ice was >500 km offshore: a female with a yearly cub swam 687.1 km in just over 9 days, as described in detail by Durner et al. (2011). This bear was one of only two individuals in the Pagano et al. study described here that swam from land to the main pack ice edge; after a few weeks meandering around at the edge of the pack ice, this bear then walked back to shore on the rapid-forming ice, arriving on land at the end of October. The second longest swim (366.0 km) was recorded in 2005, when the pack ice edge was about the same distance offshore as in 2009.
Pagano et al. conclude: “we show that both adult female polar bears and their dependent young possess an ability to swim long distances.” They also state that “most of the long-distance swimming events that we identified involved bears swimming from unconsolidated sea ice to the main pack ice or to land.” In other words, few swims recorded were from land to sea ice, indicating that during the open water season, most southern Beaufort and Chukchi Sea polar bears are on the sea ice, not on land -- a point also made by Durner et al. (2011). In addition, the results of this study suggest that despite there being little or nothing for female polar bears and their cubs to eat on shore during the late summer months in the southern Beaufort Sea, the few bears that remain on shore are apparently not so hungry that they are undertaking long-distance swims to the pack ice to relieve their fast, although they appear able to do so. Despite an overall decline in September sea ice levels between 1979 and 2010, this study found no significant correlation between increased long-distance swims and increased amounts of open water in this region over time. [Archived 12 June 2012]
See the entire NIPCC summary here.
Featured Quote #39 posted May 17, 2013
“Across the entire Bering Sea, the ice is slowly growing at a time when it should be breaking up, said Kathleen Cole, lead ice forecaster in Alaska for the National Weather Service. “We’re actually making ice rather than having it dissipate,” she said. May 17, 2013 (Alaska Dispatch).
From this news report: “The cold, hard facts: New century frigid for Alaska” by Alex DeMarban May 17, 2013.
“With cyclists hammering through snow-showers on Bike to Work Day and greening lawns now blanketed in slushy white, it should come as no surprise that the longtime cooling spell that put the chill on global warming in Alaska shows no signs of letting up.
The state’s overall temperature dipped 2.4 degrees during the first decade of the new century, a notable shift from the previous 100 years, which had generally trended warmer, according to a study published last summer by the Alaska Climate Research Center at the University of Alaska Fairbanks [see The Climate of Alaska for 2011]
The authors suggested that growing winter ice in the Bering Sea — the result of cooler surface temperatures — led to lower temperatures across nearly all of Alaska. Meanwhile, thinning ice in the Arctic Ocean led to warming in one slice of the state: the North Slope atop Alaska.
Those trends are continuing, according to follow-up papers released by Wendler, Blake Moore and Kevin Galloway.
And across the entire Bering Sea, the ice is slowly growing at a time when it should be breaking up, said Kathleen Cole, lead ice forecaster in Alaska for the National Weather Service.
“We’re actually making ice rather than having it dissipate,” she said.
But once the weather warms back up, sea ice in the Bering should vanish more quickly than it did last year because it’s not as dense. She’s predicting an ice-free Bering Sea starting July 1.
“All I want is 60-degree days,” said Cole, from her office in Anchorage. “I really, really want 60 degrees.”
See the rest of the story here.
Below is an ice extent map for May 17, 2013, which clearly shows how much more than normal sea ice is present in the Bering Sea.