Talk:Polar bear

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Good articlePolar bear has been listed as one of the Natural sciences good articles under the good article criteria. If you can improve it further, please do so. If it no longer meets these criteria, you can reassess it.
January 6, 2011Good article nomineeListed

Out of date controversies[edit]

I removed some out of date controversies.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.[1]


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.[2] An editorial in The New York Times said that "these two moves are almost certainly, and cynically, related."[3][4] 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.[2] On 28 April 2008, a Federal court ruled that a decision on the listing must be made by 15 May 2008;[5] the decision came on 14 May to make the polar bear a protected species.[1] 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,[6] 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.[6] Environmental groups have pledged to go to court to have the Endangered Species Act interpreted in such a way.[6] On 8 May 2009, the new administration of Barack Obama announced that it would continue the policy.[7] 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.[8] 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.[9]~~

References

  1. ^ a b Barringer, Felicity (15 May 2008). "Polar bear is made a protected species". The New York Times. Retrieved 7 June 2008.
  2. ^ a b Hebert, H. Josef (8 March 2008). "Delay in polar bear policy stirs probe". San Francisco Chronicle. Retrieved 9 March 2008.
  3. ^ Cite error: The named reference campbell was invoked but never defined (see the help page).
  4. ^ Editorial (15 January 2008). "Regulatory Games and the Polar Bear". The New York Times. Retrieved 20 October 2008.
  5. ^ Biello, David (30 April 2008). "Court obrders U.S. to stop keeping polar bear status on ice". Scientific American News. Retrieved 8 June 2008.
  6. ^ a b c Cite error: The named reference hassett was invoked but never defined (see the help page).
  7. ^ U.S. to keep Bush administration rule on polar bears, McClatchy Newspapers, 8 May 2009
  8. ^ Joling, Dan (5 August 2008). "Alaska sues over listing polar bear as threatened". The Globe and Mail. Retrieved 29 August 2008.
  9. ^ Template:Cite news''

Long night[edit]

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.

Analemma Earth.png).

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)

Exchange over ice in the fall[edit]

This can't be answered by reasoning / derivation by editors. It's going to need information from a credible source. It is certainly possible for ice to break up when the (air) temperatures are dropping. And ice is more thermally coupled to the water than the air. Water temperature generally lags changes in air temperatures and could still be at the temperature to continue to melt ice even after the air temperature has started to drop. North8000 (talk) 17:18, 11 February 2018 (UTC)

@North8000: Well, as I understand it, the water and the wetted surface of the ice will be at the same temperature, about −2°C. When the air temperature drops below this the water starts to get colder and this causes more ice to form. Eric Kvaalen (talk) 12:17, 13 February 2018 (UTC)
@Eric Kvaalen: Mostly true except for "starts to get colder" is not synchronous with more ice forming. Looking at the microscopic level (the zillionth of an inch at the wetted surface) can be misleading. The water temperature that really matters regarding what's happening to the ice is the bulk water temperature near the ice. If it's below ~-2C the ice freezes more and above ~-2C the ice does some melting. So, in the fall, you, could have the water at +3C, the air gets cold and starts dropping the water temperature. But until it drops it to ~-2C (which could take days or weeks) the ice can still be melting. North8000 (talk) 22:43, 13 February 2018 (UTC)


@North8000: Well, I think that if you have a lot of ice floating in the sea, the ice will cool the water to its freezing point (−2°C) or else it will melt completely.

Come to think of it, we're going on a wrong premiss. The water (and ice) can cool off even if the air is warmer than the water – by radiation. The water surface radiates far-infrared radiation toward the sky. If this is greater than the sunlight (and moonlight!) that it absorbs, then it tends to get colder. In fact it is the earth's surface that heats and cools the air more than the other way around.

Eric Kvaalen (talk) 06:09, 14 February 2018 (UTC)

That's several new topics. The whole surface of the earth emits infrared tending to cool itself. Clouds, blue skies and the sun also do this towards the tending to heat the earth. You need a clear night for significant net cooling as you describe. And there's another huge factor at work which you haven't mentioned. The large amount of energy absorbed and released by the state change between water and ice, separately from temperature change. My initial comment was based on trying asses the result of dominant factors of the zillions of factors at work. Nice conversation! Northern (talk) 14:31, 14 February 2018 (UTC)

Kevin Hart 2018

Many studies show that Polar bears are very smart animals and are great with there small cubs.

Semi-protected edit request on 23 September 2018[edit]

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)