Talk:Polar bear/Archive 7

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Long night

We need some information on how polar bears manage when the sun goes down for months at a time in the winter? Eric Kvaalen (talk) 08:09, 11 February 2018 (UTC)

They don't photosynthetize, they eat seals. Or you meant their night vision? BatteryIncluded (talk) 16:30, 11 February 2018 (UTC)

I think that days with zero daylight are rare in their area. They live in the arctic but not at the north pole. More typical in the winter for them would be short or very short daylight. Including "twilight" type light even when the sun is below the horizon. North8000 (talk) 13:38, 12 February 2018 (UTC)

Right, it is more like a twilight. Anyway, they rely mostly on smell. So I am not sure on the nature of Eric's question. BatteryIncluded (talk) 17:40, 12 February 2018 (UTC)

@North8000 and BatteryIncluded: Yes, I mean how do they see. Take a look at this map, showing the 19 subpopulations and where they live. Some of them, like the Southern Hudson Bay population, live south of the Arctic Circle. But some live way north of it. For example, the Kane Bay group. It looks to me as though the southern edge of their range is the Smith Sound at a latitude of about 78°. When the sun is 6° or more below the horizon, it's pretty dark. See Twilight. At 78° latitude, this is the case when the sun's latitude is south of 18°S. That's from about November 1st to February 1st.

).

Eric Kvaalen (talk) 12:17, 13 February 2018 (UTC)

My response was to "sun goes down for months at a time" and was just a general note about typical for the main populations. I'm not disagreeeing with you, but upon a closer look I'm not seeing a specific point being established in your last post. The graph is "a plot of the position of the sun at 12:00 noon at the Royal Observatory, Greenwich (latitude 51.4791° north, longitude 0°) during 2006."

There's another phenomena at work which is the wide range of light levels for vision. For examples, humans can see at about 1 /20,000th the light level of full sun, and can see pretty well at 1/2,000 th the light level of full sun. North8000 (talk) 12:41, 13 February 2018 (UTC)

@North8000 and BatteryIncluded: The graph just shows the position of the sun in the sky. I grabbed it from the Analemma article. It's not important that it is supposedly "at" the Royal Observatory. The point is that from early November to February the sun is more than 6° below the horizon where the Kane Bay polar bears live. When the sun is that far below the horizon, you don't see any sign of it on the horizon, so it's almost like midnight.

But there is another source of light – the moon (not to mention the stars). The moon is "up" on average 12 hours a day. There are a few days every tropical month (27.3 days) when it doesn't come up at all at latitude 78°, but there are also a few days that it's up all 24 hours, for example when the moon is full (in the winter). Whenever the moon is north of 12°N, like in Gemini, it will be up 24 hours a day, and whenever it is south of 12°S, like in Sagittarius, it will be below the horizon for the whole 24 hours. The moon can be as high as 12°+28.5°=40.5° when we are close to a major lunar standstill (though we have recently gone through a minor lunar standstill so the maximum elevation of the moon at 78°N is only about 30.5°). I wonder whether the bears are active when the moon is up and not when the moon is down.

Eric Kvaalen (talk) 05:54, 14 February 2018 (UTC)

6° below the horizon is just like a sunset or dawn. I have read nothing in the literature suggesting any kind of specialized adaptation to the dark (nocturnal habits) to merit a section/paragraph on that. The bears manage just fine in twilight as they rely on smell to find prey. BatteryIncluded (talk) 14:43, 14 February 2018 (UTC)

@North8000 and BatteryIncluded: Battery, check here to see the time of "dusk" where you live, and then go out and see how much light there is (not from streetlights and so on). That's when the sun is 6° below the horizon.

By the way, I just redd an interestin story about the need for moonlight in the Arctic or Antarctic. See Historically significant lunar eclipses#15 July 1916.

Eric Kvaalen (talk) 09:31, 15 February 2018 (UTC)

Cool! Thanks! North8000 (talk) 13:26, 15 February 2018 (UTC)

Semi-protected edit request on 23 September 2018

I just thought that I could add some more details that I know about Polar Bears. Polar Bears are my favorite animal so it would be wonderful if you could let me do some changes.

                                            Thanks!
                                            Lilygirl110606 Lilygirl110606 (talk) 21:11, 23 September 2018 (UTC)

@Lilygirl110606: You'll be able to edit this article once your account is 4 days old and you've made 10 edits. In the meantime, you can request that an edit be made here on the talk page. Simplexity22 (talk) 21:29, 23 September 2018 (UTC)

"Current estimates"

The sentence that starts with "Current estimates" should probably include the years of the relevant estimates (2005 and 2015, I believe). 72.49.111.86 (talk) 15:14, 12 December 2018 (UTC)

Ice bear redirect

Ice bear currently redirects to polar bear. I plan to add back the ice bear hatnote per the WP:R#ASTONISH guideline (as discussed at User_talk:North8000#Ice_bear_redirect). One thing I notice is that "ice bear" is not mentioned nor bolded in the lead as WP:R#ASTONISH advises. FWIW, it is at Britanica.com. I'll leave it to others what if anything needs to be done. Another option is that ice bear should be a disambiguation page, and polar bear should not be its WP:PRIMARYTOPIC.—Bagumba (talk) 07:37, 14 January 2019 (UTC)

There is a wrong Latin name

The name of the harp seal is presented as (pusa groenlandicus) but it really is (pacophilus groenlandicus) אריה סמסון (talk) 18:35, 15 January 2019 (UTC)

Corrected. PepperBeast (talk) 19:22, 15 January 2019 (UTC)

Polar bear evolution

Newer study says, 150,000 years ago polar bear DNA went to brown bear, not the other way around. Polar bear developed about 400,000 years ago.

Shiping Liu et al.: Population Genomics Reveal RecentSpeciation and Rapid EvolutionaryAdaptation in Polar Bears. Cell157, 785–794, May 8, 2014, p. 787 https://www.cell.com/action/showPdf?pii=S0092-8674%2814%2900488-7 --Huhu8888888 (talk) 17:41, 30 November 2019 (UTC)

Largest extant predatory carnivore claim confusing

Maybe I don't fully understand the claim, but it seems wrong. A saltwater crocodile, for example, is both bigger and heavier than a polar bear, and is a predatory carnivore, right? One citation doesn't seem to mention size and the other only claims it is the largest species of bear. — Preceding unsigned comment added by 73.134.109.147 (talk) 05:47, 14 September 2020 (UTC)

While it doesn't entirely answer the question, I was able to find this source that says that it's the largest terrestrial carnivore. I guess it's possible that someone misinterpreted that as largest carnivore overall? M Imtiaz (talk · contribs) 22:06, 16 September 2020 (UTC)

"Carnivore" could very well be referring to members of Carnivora, rather than animals that eat meat. After all, sperm whales are quite obviously larger, carnivorous, and predatory. --150.243.38.22 (talk) 20:52, 29 September 2020 (UTC)

Polar bear evolution

Newer study says, 150,000 years ago polar bear DNA went to brown bear, not the other way around. Polar bear developed about 400,000 years ago.

Shiping Liu et al.: Population Genomics Reveal RecentSpeciation and Rapid EvolutionaryAdaptation in Polar Bears. Cell157, 785–794, May 8, 2014, p. 787 https://www.cell.com/action/showPdf?pii=S0092-8674%2814%2900488-7 --Huhu8888888 (talk) 17:41, 30 November 2019 (UTC)

Largest extant predatory carnivore claim confusing

Maybe I don't fully understand the claim, but it seems wrong. A saltwater crocodile, for example, is both bigger and heavier than a polar bear, and is a predatory carnivore, right? One citation doesn't seem to mention size and the other only claims it is the largest species of bear. — Preceding unsigned comment added by 73.134.109.147 (talk) 05:47, 14 September 2020 (UTC)

While it doesn't entirely answer the question, I was able to find this source that says that it's the largest terrestrial carnivore. I guess it's possible that someone misinterpreted that as largest carnivore overall? M Imtiaz (talk · contribs) 22:06, 16 September 2020 (UTC)

"Carnivore" could very well be referring to members of Carnivora, rather than animals that eat meat. After all, sperm whales are quite obviously larger, carnivorous, and predatory. --150.243.38.22 (talk) 20:52, 29 September 2020 (UTC)

Physical characteristics

Resolved

This sentence from the physical characteristics section: "Polar bears can swim 10 km/h (6 mph)." should probably read "Polar bears can swim at a speed of 10 km/h (6 mph)." — Preceding unsigned comment added by 213.91.212.222 (talk) 09:18, 16 February 2021 (UTC)

Thanks. I've changed to "Polar bears can swim at 10 km/h (6 mph)." Adrian J. Hunter^{(talk•contribs)} 12:19, 27 March 2021 (UTC)

Overheating at 10 degrees Celsius

Can someone help me find which source has the following phrase?

"their hide and their fur; they overheat at temperatures above 10 °C (50 °F), and are nearly invisible under infrared photography.[62]"

I went through both sources, but couldn't find it. I also remember reading somewhere they can overheat in temperatures as low as 10 degrees Celsius, when exerting strenuous physical activity, but can tolerate temperatures as high as 25 degrees Celsius when not.

I think the difference between the two should be explained clearly in the article, otherwise makes people think they don't exist in places with summer temperatures of over 10 degrees, which isn't the case at all. Some of the most viable populations experience mean summer daytime temperatures of over 15-20 degrees Celsius annually. 85.153.202.218 (talk) 09:24, 27 March 2021 (UTC)

Sounds like nonsense to me. Adelaide Zoo had polar bears and we get temperatures well above 40 °C. I checked source 62 and none of the instances of "overheat" supported the claim. I've removed they overheat at temperatures above 10 °C (50 °F), and are nearly invisible under infrared photography.<ref name="stirling1988" /> "Infra" could not be found in a search of the reference, and that sounds ridiculous, anyway – polar bears are very good at maintaining regular body temperature despite the cold, not at surviving with a low body temperature, so why wouldn't they show up in infrared? Adrian J. Hunter^{(talk•contribs)} 12:17, 27 March 2021 (UTC)

Infrared photography is based on surface temperature, not core body temperature, so there's actually a smidgin of truth to this − but it's overstated, as there are many clear IR images of polar bears [1] [2] [3]. Adrian J. Hunter^{(talk•contribs)} 12:50, 27 March 2021 (UTC)

There's actually a statement like this in the other source (60): "Surprisingly, a polar bears coat is so thick and so effective that almost no heat escapes from the bears body. Scientists tried an experiment. They took pictures of polar bears with an inf rare* camera. Infrared photos show heat, yet the polar bear picture came out blank. The only heat that escaped from the bears’ bodies was their breath." But of course, like you said, it would depend on the camera settings and the temperature of the surrounding environment. So a generalized claim concerning all possible scenarios is an overkill. 85.153.202.218 (talk) 06:25, 28 March 2021 (UTC)

Out of date controversies

I removed some out of date controversies. Rather than revert, how about some fresher contoversies?

"While listing the polar bear as a threatened species, the Interior Department added a seldom-used stipulation to allow oil and gas exploration and development to proceed in areas inhabited by polar bears, provided companies continue to comply with the existing restrictions of the Marine Mammal Protection Act. The main new protection for polar bears under the terms of the listing is that hunters will no longer be able to import trophies from the hunting of polar bears in Canada.

The ruling followed several years of controversy. On 17 February 2005 the Center for Biological Diversity filed a petition asking that the polar bear be listed under the Endangered Species Act. An agreement was reached and filed in Federal district court on 5 June 2006. On 9 January 2007, the United States Fish and Wildlife Service proposed to list the polar bear as a threatened species. A final decision was required by law by 9 January 2008, at which time the agency said it needed another month. On 7 March 2008, the inspector general of the U.S. Department of the Interior began a preliminary investigation into why the decision had been delayed for nearly two months. The investigation is in response to a letter signed by six environmental groups that United States Fish and Wildlife Director Dale Hall violated the agency's scientific code of conduct by delaying the decision unnecessarily, allowing the government to proceed with an auction for oil and gas leases in the Alaska's Chukchi Sea, an area of key habitat for polar bears. The auction took place in early February 2008. An editorial in The New York Times said that "these two moves are almost certainly, and cynically, related." Hall denied any political interference in the decision and said that the delay was needed to make sure the decision was in a form easily understood. On 28 April 2008, a Federal court ruled that a decision on the listing must be made by 15 May 2008; the decision came on 14 May to make the polar bear a protected species. Upon listing the polar bear under the Endangered species act, the Department of the Interior immediately issued a statement that the listing could not be used to regulate greenhouse gas emissions, although some policy analysts believe that the Endangered Species Act can be used to restrict the issuing of federal permits for projects that would threaten the polar bear by increasing greenhouse gas emissions. Environmental groups have pledged to go to court to have the Endangered Species Act interpreted in such a way. On 8 May 2009, the new administration of Barack Obama announced that it would continue the policy. On 4 August 2008, the state of Alaska sued U.S. Interior Secretary Dirk Kempthorne, seeking to reverse the listing of the polar bear as a threatened species out of concern that the listing would adversely affect oil and gas development in the state. Alaska Governor Sarah Palin said that the listing was not based on the best scientific and commercial data available, a view rejected by polar bear experts. In March 2013, a United States Appeals Court ruling upheld the "threatened" status of the polar bear against a challenge led by the State of Alaska.~~

References

Semi-protected edit request on 17 November 2021

Can i pleaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaseeeeeeeeeeeeeeeeeeeeeee edit this page 2601:647:4F80:4CA0:6D55:1148:791A:1262 (talk) 06:38, 17 November 2021 (UTC)

 Not done: this is not the right page to request additional user rights. You may reopen this request with the specific changes to be made and someone will add them for you, or if you have an account, you can wait until you are autoconfirmed and edit the page yourself. Cannolis (talk) 06:46, 17 November 2021 (UTC)

Semi-protected edit request on 23 February 2022

Section "Life history and behaviour"

Please add the word "been" after "found" to the following sentence: The remains of polar bears have found in the stomachs of large Greenland sharks (Somniosus microcephalus), although it certainly cannot be ruled out that the bears were merely scavenged by this slow-moving, unusual shark. Velvetpirate (talk) 01:28, 23 February 2022 (UTC)

 Done PepperBeast (talk) 01:37, 23 February 2022 (UTC)