How “Science” Counts Bears

Guest essay by Jim Steele, director emeritus, San Francisco State University

The Inuit claim “it is the time of the most polar bears.” By synthesizing their community’s observations they have demonstrated a greater accuracy counting Bowhead whales and polar bears than the models of credentialed scientists. To estimate correctly, it takes a village. In contrast the “mark and recapture” study, which claimed the polar bears along South Beaufort Sea were victims of catastrophic global warming and threatened with extinction, relied on the subjective decisions of a handful of modelers.

In mark and recapture studies, the estimate of population abundance is skewed by the estimate of survival. For example, acknowledging the great uncertainty in his calculations of survival, in his earlier studies polar beat expert Steven Amstrup reported three different population estimates for bears along the South Beaufort Sea. If he assumed the adult bears had an 82% chance of surviving into the next year, the models calculated there were 1301 bears. If survivorship was 88%, the abundance climbed to 1776 bears. If he estimated survivorship at a more robust 94%, then polar bear abundance climbed to 2490.1 Thus depending on estimated survival rates, a mark-and-recapture study may conclude that the population has doubled, or that it has suddenly crashed.

Here are the simplified basics of estimating survival.

Assume the fenced-off area is your study area. For statistical reasons you ignore observations outside that designated area. During the first year, you reach into your study area and capture four bears, which you then mark by painting a big white cross on their chests. (Researchers first painted big numbers on polar bears for easy identification from a helicopter, but the tourism industry complained that it ruined photographs. They now use discreet ear tags and a tattoo under their upper lip in case the tag falls off.)

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The next year you return to your study area and randomly capture four more bears. However, only two are marked with a white cross. Now the researcher must decide what happened to the two missing bears that were marked last year. Did they die or did they avoid detection? Assuming they avoided detection, then survival is estimated to be 100%. Since the two recaptured bears represent half of last year’s marked bears, the models assume the four bears captured during the study’s second year similarly represent about half of the total population. So the models estimate that there were at least eight bears within the study area.

clip_image004However the calculations change if the researcher assumes the missing marked bears died. In this case, it means that in the second year you captured every possible marked bear. So your model assumes that you also captured every possible bear in the study area. Now the model estimates that there were only about four bears living in your study area. Because the survival rates are greatly affected by this guesswork, these estimates are called “apparent survival rates.”

Apparent survival rates are heavily biased by any migration in and out of the study area. The earliest mark and recapture models were tested on rodent populations, and the statisticians warned that barriers should be erected to prevent the rodents from moving. Otherwise all statistical calculations were totally unreliable. But that tactic is impossible for highly migratory polar bears.

Unlike other species that defend a territory with reliable resources, polar bears never defend territories. They walk and swim across great distances and will congregate wherever the Arctic’s ever-shifting food supply becomes most abundant. A study of radio-collared female bears denning on Wrangel Island determined that after the bears left the island they travelled an average distance of about 3700 miles.2 Although much of their travel is confined within a less extensive region, one radio-collared female was observed in Alaska in late May and tracked to Greenland by early October.3 Such wide-ranging movements allow rapid adjustments to the Arctic’s annually varying food supplies. However it presents great difficulties for any mark and recapture study. Deciding if a bear was travelling or died thus becomes guesswork, and the amount of guesswork increases with shorter studies.

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Instead of erecting barriers, a small percentage of female bears are equipped with radio collars. (Males have such big necks the collars will slide off. Young bears outgrow their collars too quickly and could choke themselves to death. So typically only adult females are collared.) Because collared bears can be tracked, there is no guesswork unless the batteries die. If a radio-collar remains in one spot for a long time, researchers locate the collar and determine if the bear died or just lost the collar. The vastly more accurate survival-rate data produced by collared bears is called “biological survival”. Researchers normally use biological survival to evaluate the accuracy of “apparent survival”. For example, if a large percentage of collared bears survived but simply moved out of the study area, then researchers assume a similar percentage of marked bears had also moved away. In that case, a low apparent survival rate was an illusion due to temporary migration and the avoidance of detection, not death.

Amstrup diligently followed up his earlier study on the apparent survival of South Beaufort Bears using radio-collared bears over a 12-year period. It turned out that his high-end apparent survival estimate of 94% was still too low. If only natural deaths were used, polar bears had a 99.6 % biological survival rate.4 Most bears died at the hands of hunters. If death at the hands of hunters was also considered, then biological survival was still higher than apparent survival, but fell to 96.9%. In 2001 Amstrup concluded that the South Beaufort Sea population was increasing and the current hunting quotas insured a growing population.

To appreciate the magnitude of the problem in estimating apparent survival rates, imagine a human mark-and-recapture study in which the local supermarket is your study area. For statistical reasons, you can only use observations inside your defined study area to determine whether or not your neighbors are alive or dead. (Because you recognize your neighbors’ faces, there is no need to add ear tags or body paint.) How often do you see your neighbors in that store? Although my neighbors and I shop at the same supermarket 2 or 3 times each week, 50+ weeks a year, I don’t see 90% of them at the supermarket more than once every 5 to 10 years. If I was doing a human mark and recapture study, and did not see my neighbors after 5 years, my model would assume most of my neighbors had died! For that reason mark and recapture studies must persist for several years in order to estimate the probability of marked animals being alive but not observed. Otherwise they will underestimate survival. Amstrup warned ““Models that predict rapid increases or decreases in population size would not mirror reality”

Perhaps it was the growing pressure from adversarial lawsuits, and speculation that the polar bears were endangered from CO2 warming, but in a subsequent series of USGS publications coauthored by Amstrup, they suddenly emphasized the illusion of apparent survival and downplayed biological survival to suggest the polar bears were facing extinction. The study was far too short to reliably estimate survival. Still during the first three years of their “extinction” study, the researchers reported apparent survival ranging from 92‑99%574. The higher estimate was the same as the biological survival rates of Amstrup’s radio-collared bears. However apparent survival dropped dramatically for the last two years of the study. The final years of a study always underestimate survival because newly marked are less likely to be observed a second time relative to bears marked in the first years of a study. Claiming “radiotelemetry captures present methodological difficulties” they oddly excluded radio-collared data from critical statistical tests!5 Despite knowing that biological survival rates had never rapidly changed before, and despite knowing more collared bears migrated outside their study area in 2004 and 2005, the USGS report argued polar bear survival had abruptly dropped from 96‑99% in 2003, down to 77% in 2004.6

In their first USGS report, the authors demonstrated high integrity in their analyses and were upfront about the problems of their models, writing, “the declines we observed in model-averaged survival rates may reflect an increase in the number of “emigrants” toward the end of the study, and not an actual decrease in biological survival”, and they noted male bears had exhibited unusually high transiency.5 When apparent survival rates were high, only 24% of the collared females had wandered outside the study area. In contrast during last two years of the study when apparent survival plummeted, the number of collared bears wandering outside the study area had nearly doubled to 47% in 2005 and 36% in 2006, but they never published their biological survival rates. They chose to dismiss the high percentage of bears migrating out of the study area and subjectively chose to argue fewer captured bears meant more dead bears. The authors oddly argued that using 18 years of data the bears are eventually observed in the study area. In keeping with my human/supermarket analogy, it was the equivalent of labeling all your neighbors dead if you don’t see them in the market over a two year span, because over a ten year period you always see them at least once. We need Steve McIntyre to do a polar bear audit!

The dramatic drop in survival meant 400 bears suddenly died but there were no carcasses. To support their unprecedented claims, one USGS report emphasized in the abstract that subadult males showed reduced body condition and that was evidence of nutritional stress that lowered survival.7 However if you read the results section and did some math, you discover that subadult males only represented 5% of all captures. The other 95% were stable or improving. In contrast, adult females represented about 34% of all captures, and despite being under the most stress due to an eight-month fast while giving birth and nursing their cubs, their body condition had improved. That good news wasn’t ever mentioned in the abstract, you had to search the results section: “There was no trend in mass of adult females during the study, but the mean BCI [body condition index] of females increased over time”.7

Their abstract also implied “a decline in cub recruitment” to support their model’s uncharacteristic dip in survival rates. But that too was an illusion. Recruitment compares the number of cubs in the spring with the number of cubs in the fall. Using older studies their observed results found that the number of cubs per female had increased between 1982 and 2006 during the spring. This would be expected. When the female body condition increases, they usually produce more cubs.8 To counteract that good news, the authors then argued there was a decline in cubs during the fall, and thus a decline in recruitment. However they had not surveyed in the fall since 2001.7 They were using deceptive zombie data to support a bad model.

That is how global warming advocates counted bears to refute the claims of the Inuit. That was the driving evidence that led to the uplisting of the polar bear as threatened species. Based on such studies Dr. Derocher, chairman of the IUCN’s Polar Bear Specialist Group (PBSG) warned, “It’s clear from the research that’s been done by myself and colleagues around the world that we’re projecting that, by the middle of this century, two-thirds of the polar bears will be gone from their current populations”.

Don’t count on it!

Jim Steele monitored bird populations on the Tahoe National Forest for 20 years using mark and recapture. Director emeritus, Sierra Nevada Field Campus, San Francisco State University

Adapted from the chapter “Inuit and Illusions in the Time of the Most Polar Bear” in Landscapes & Cycles: An Environmentalist’s Journey to Climate Skepticism

Literature Cited

1. Amstrup, S. C., Stirling, I., and Lentfer, J. W. (1986), “Past and Present Status of Polar Bears in Alaska,” Wildlife Society Bulletin, 14, 241–254.

2. Garner, G. et al. (1994) Dispersal Pattersn of Maternal polar bears from the denning concentration on Wrangel Island. Int. Conf. Bear Res. and Manage. vol. 9, p. 401-410.

3. Durner, G., and Amstrup, S. (1995) Movements of a Polar Bear from Northern Alaska to Northern Greenland. Arctic, vol. 48, p. 338– 341

4. Amstrup, S. and Durner, G. (1995) Survival rates of radio-collared female polar bears and their dependent young. Canadian Journal of Zoology, vol. 73. P. 1312‑1322.

5. Regehr, E.V., Amstrup, S.C., and Stirling, Ian, 2006, Polar bear population status in the southern Beaufort Sea: U.S. Geological Survey Open-File Report 2006-1337, 20 p.

6. Regehr, E., et al. (2010) Survival and breeding of polar bears in the southern Beaufort Sea in relation to sea ice. Journal of Animal Ecology 2010, 79, 117–127

7. Rode, K. et al. (2007) Polar Bears in the Southern Beaufort Sea III: Stature, Mass, and Cub Recruitment in Relationship to Time and Sea Ice Extent Between 1982 and 2006. USGS Alaska Science Center, Anchorage, Administrative Report.

8. Derocher, A., and Stirling, I., (1998) Offspring size and maternal investment in polar bears (Ursus maritimus). Journal of Zoology (Lond.) vol. 245, p.253–260.

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July 3, 2013 3:49 am

Thank you.

johnmarshall
July 3, 2013 4:02 am

Very interesting, thanks.
So, there are lies, damn lies and bear stats.

Txomin
July 3, 2013 4:13 am

Thank you essay, indeed. These kinds of frauds should be prosecuted.

Bob
July 3, 2013 4:15 am

Very good post. Thanks

Joe Public
July 3, 2013 4:19 am

If you’ve been captured once, experience gained helps you evade recapture.

Peter Miller
July 3, 2013 4:27 am

Just another excellent reason why it is so important to spend trillions of dollars on ‘climate change’.
Data can be manipulated by statisticians to prove whatever you want, which is about the only thing you can be sure of in ‘climate science’.

July 3, 2013 4:31 am

A demographic study of radio-collared professors should yield even more shocking results.

Editor
July 3, 2013 4:51 am

Thanks, Jim.

Alan D McIntire
July 3, 2013 4:54 am

“If only natural deaths were used, polar bears had a 99.6 % biological survival rate.”
That can’t be right. With a 99.6 survival rate, an average bear’s life expectancy would be
100/0.4 = 250 years
” Most bears died at the hands of hunters. If death at the hands of hunters was also considered, then biological survival was still higher than apparent survival, but fell to 96.9%”
That would give a life expectancy of 100/3.1 = 32.26 years, plausible, but I think that would still be pretty high for creatures in the wild.

commieBob
July 3, 2013 5:01 am

I haven’t read past the first couple of paragraphs and seen a couple of illustrations. This post set off my crap-o-meter.

… which you then mark by painting a big white cross on their chests.

Polar bears are white folks. Polar bears are always white except when they come out of their dens and are dirty white. You can’t identify them by painting them with white paint. Whoever produced this post clearly isn’t intimately familiar with polar bears.
Notwithstanding the above, this isn’t a defense of the polar bear scientists. I have known some and they’re not nearly as stupid as some people paint them. I have also known some of the Inuit. Neither group has a lock on the truth. In spite of the fact that there are no trees to hide them, polar bears are hard to count. They’re white, the snow is white, the sky is often white, the bears are invisible.
REPLY: Note, the title says “bears”, which include white, brown, black, and the occasional pink bear – Anthony

July 3, 2013 5:05 am

How science counts sheep.
A man was driving his shiny new BMW and came across a farmer and a huge flock of sheep. He told the shepherd, “I will bet you $100 against one of your sheep that I can tell you the exact number of sheep in this flock.”
The shepherd thinks it over; it’s a big flock so he takes the bet. The driver pulls out his WiFi laptop, gets a a pattern recognition count working on Google Earth.
Inside 3 minutes, “It’s 973,” says the man. The shepherd is astonished, because that is exactly right. He says “OK, I’m a man of my word, take an animal.” The man picked one up and began to walk away.
“Wait,” cried the shepherd, “Let me have a chance to get even. Double or nothing that I can guess your exact occupation.” The man thought for a moment a said “sure.”
“You are a top economist for the federal government,” said the shepherd.
“Amazing!” responded the man, “You are exactly right! But tell me, how did you deduce that?”
“Well,” said the shepherd, “Put down my dog and I will tell you.”

stan stendera
July 3, 2013 5:08 am

I love polar bears. I think they are one of the ecological marvels of the age. That being said I would not want to meet one in a dark alley without a large gun in my hands, and even then I would not be sure of my survival. That is why in a nutshell they are an ecological marvel of the age.

Editor
July 3, 2013 5:15 am

There ought to be some sizable differences in male vs female travels. Perhaps people could get a grant from Coca Cola to come up with a good radio tracking harness for males.
I know some human females who’d like a radio tracker for their males….

Gaudenz Mischol
July 3, 2013 5:21 am

“Polar bears are white folks. Polar bears are always white except when they come out of their dens and are dirty white. You can’t identify them by painting them with white paint. Whoever produced this post clearly isn’t intimately familiar with polar bears.”
If you read carefully you will see that this is thought as an example and has nothing to do with the studies mentionend

July 3, 2013 5:26 am

Very interesting and informative. Thank you.
You mentioned changes to marking techniques due to complaints from the tourist industry (polar bear safaris, I assume). Did anyone think to correlate data from the tourist industry? If bear populations are declining I would expect that to mean fewer sightings on these safaris.

July 3, 2013 5:28 am

Once again, this reminds me of the statistics course I had to take in college. Early on in the class, we were taught how to make stats lie while still telling the truth. That is the only thing I remember from that class because because I didn’t need statistics for my computer science degree.

July 3, 2013 5:29 am

Dr. Steele,
Thank you for an insightful post. I concur with the overview of your new book
“Landscapes and Cycles will enlighten anyone concerned with climate change and the fate of endangered species. Not only is it fascinating reading for the general public, it should required reading for every high school and college environmental studies class.”

Alberta Slim
July 3, 2013 5:39 am

Obama and the EPA are closing Coca Cola f because they are producing product that is releasing CO2 into the atmosphere, causing CAGW ;^)

commieBob
July 3, 2013 5:51 am

Gaudenz Mischol says:
July 3, 2013 at 5:21 am
… If you read carefully you will see that this is thought as an example and has nothing to do with the studies mentionend

At some point it is important to understand your subject material. No matter how good your logic and statistical methods, you can still arrive at absolutely laughable conclusions if you don’t understand the material. Geoff Sherrington makes the point elegantly.

Geoff Sherrington says:
July 3, 2013 at 5:05 am
How science counts sheep. … “Well,” said the shepherd, “Put down my dog and I will tell you.”

What I said was: “Whoever produced this post clearly isn’t intimately familiar with polar bears.” I stand by that unless someone can produce evidence to the contrary.

July 3, 2013 6:02 am

So, sadistics, again…..
Thanks Dr. Steele.

July 3, 2013 6:11 am

commieBob says: I haven’t read past the first couple of paragraphs and seen a couple of illustrations. This post set off my crap-o-meter. … which you then mark by painting a big white cross on their chests.
Of course polar bear are white, and I was worried the brown bears may confuse some, but the illustrations are meant to show how any mark and recapture works.

Gary
July 3, 2013 6:12 am

The difference between the Inuit and scientists, as far as estimating polar bear population size is concerned, is that one group is expert and the other amateur. Always consider the source of information when judging its value. Meta-data are important.

July 3, 2013 6:13 am

Jim Steele, this is a great article. Ignore the noisy drunk in the back of the bar.

commieBob [July 3, 2013 at 5:01 am] says:
commieBob [July 3, 2013 at 5:51 am] says:

Sleep it off and then ask one of the moderators to strike those two posts. You’ll be thankful later.

July 3, 2013 6:15 am

The American Libertarian refers to these times as “the time of much fudged data”.

July 3, 2013 6:23 am

Why would they be trying to refute the Inuit? I mean, after all, what do the Inuit know? There’s no point in trying to refute them, it’s a waste of resources that could be better spent staying south of the Arctic Circle, employing robust models and making videos of polar bears raining from the sky.

Chris4692
July 3, 2013 6:24 am

commieBob says:
July 3, 2013 at 5:51 am

What I said was: “Whoever produced this post clearly isn’t intimately familiar with polar bears.” I stand by that unless someone can produce evidence to the contrary.

The thought expeiriment example does not mention the type of bear. In the illustration the bears are clearly not white, so presumably not intended to be specifically polar bears. The type of bear is clearly not important to the example.

Lyle
July 3, 2013 6:31 am

Zak Unger’s book “Never Look A Polar Bear In The Eye” relates some of the biases that biologists like Amstrup hold.

July 3, 2013 6:31 am

@ Alan D McIntire. That would give a life expectancy of 100/3.1 = 32.26 years, plausible, but I think that would still be pretty high for creatures in the wild.
Your math is good. Typically bears over 20 years old are labeled as “senescent”. It is hard to definitively determine their natural longevity as trophy hunters sought the biggest bears a bush pilot could fine. With modern hunting regulations percentage of bears over 20 years as risen. Based on “harvested bears” in the western Hudson Bay, 5% of the population in 1985 and 15% in 2003 were bears older than 20 years. I haven’t seen a recent study that breaks down each age.but a 1988 study reported 2 out of 52 captured bears 24 years or older. Based on Canadian Wildlife Service mark and recapture older bears make up 8 to 9% of the population

kent Blaker
July 3, 2013 6:44 am

“It’s clear from the research that’s been done by myself and colleagues around the world that we’re projecting that, by the middle of this century, two-thirds of the polar bears will be gone from their current populations.”
Only 2/3? it is about 40 years before the middle of this century. Of the current population of polar bears how many will be alive in 40 years.?

July 3, 2013 6:54 am

Excellent essay Jim!
Very clearly presented and exceptionally useful.
I’d like to reblog this at PolarBearScience, if you don’t mind. It would make an excellent companion piece to my post from yesterday http://polarbearscience.com/2013/07/02/did-polar-bear-numbers-in-e-beaufort-fluctuate-each-decade-due-to-thick-ice-years/ and the follow-up later this week about Southern Beaufort polar bear studies.
Susan

July 3, 2013 7:06 am

@ Susan
Yes of course. I was going to pull another essay from the book on the effects of sea ice that would also fit support your article at PolarBear Science. It was the heavy ice years that detrimentally affected the ringed seals and thus the bears, even the CO2 advocates acknowledge that. For example Ian Stirling, PBSG expert, Canadian Wildlife Service wrote “Heavy ice conditions in the mid-1970s and mid-1980s caused significant declines in productivity of ringed seals, each of which lasted about 3 years and caused similar declines in the natality of polar bears and survival of subadults, after which reproductive success and survival of both species increased again.”

July 3, 2013 7:11 am


Obviously your intent is to discredit the essay versus discuss the validity of the methods or my critique. You remind me of the critics of Pixar’s “Its a Bug’s LIfe”. They denigrated the artists for portraying ants with only 4 legs and not accurately portraying the correct anatomy. As if that mattered when the ants were talking Engilsh. So to be clear, giant hands are not used to sample bears either.
If the color threw you I don’t expect you to understand the grave implications of the bad model and skewed presentation of data which is the important point

July 3, 2013 7:17 am

Thank you Jim, a good informative piece. And for all of you interested in the colour of Polar bears, their skin is actually black. Not many people know that …
Pointman

Steve Oregon
July 3, 2013 7:23 am

How many times in how many more ways will the Climate Brigade be shown to have colluded to present entirely false data and conclusions before they are suffocated under embarrassment and shame?
Just wondering.
It would seem they are approaching sufficient exposure.
What single or several things would be a nice trigger?
A ClimateGate III with Mann, Schmidt & Hansen caught ginning up tall tales?
Or did that already happen?

Jack Simmons
July 3, 2013 7:26 am

The real reason polar bears are thriving:
http://www.cocs.com/imagegallerydetail.asp?ImageID=516

Mikeyj
July 3, 2013 7:28 am

kent Blaker says:
July 3, 2013 at 6:44 am
“Only 2/3? it is about 40 years before the middle of this century. Of the current population of polar bears how many will be alive in 40 years.?”
Probably not 2/3 of the readers here today either.

Dr. Lurtz
July 3, 2013 7:30 am

Is there anything that we have been taught that is correct? I mean anything about anything!

July 3, 2013 7:38 am

Reblogged this on makeaneffort and commented:
Please, please, please read this.
It’s applicable to almost everything Scientists predict or “guess” at.
It should leave you with the question… “If “guessing” or “assuming” is required, then why not guess or assume the outcome which best fits consciously, or unconsciously, desired outcome?”
Remember, Bias is everywhere. It is unavoidable.
Where it should not be is in Science. But when your next years funding depends on a certain outcome…

July 3, 2013 7:45 am

@Dr. Lurtz
Of course there is.
Hold on while I Google that, I am sure I will find something…

July 3, 2013 7:47 am

Still searching…

July 3, 2013 7:49 am

Uh, Google says to try Bing.
Binging now…

KNR
July 3, 2013 7:57 am

The endlessly changeable ‘standards ‘ of climate science ‘ deals with this easily ‘native wisdom’ is wonderful thing when it supports ‘the cause ‘ but when it does not its meaningless rubbish as their not ‘climate scientist’ and can only see the local picture .

DonS
July 3, 2013 8:02 am

In the world of the hunter a dog which chases the wrong species is said to exhibit unsatisfactory behavior and lack attention to the task at hand. Think of a stag hound chasing a raccoon. The stag hounds posting here should stop chasing commieBob.

July 3, 2013 8:04 am

Bing put me on it’s “Subversive watch list”!
Maybe someone else can help.

eyesonu
July 3, 2013 8:04 am

Alan D McIntire says:
July 3, 2013 at 4:54 am
Re: lifespan of bears in the wild
=================
http://wiki.answers.com/Q/What_is_the_lifespan_of_a_bear
Seems that bears have a life expectancy of over 30 years in the wild. Hunting would likely target the largest and therefore likely the oldest individuals. It would be like harvesting a resource just prior to the eventual waste (death) by natural cause.
—-
This is an excellent article by Prof Jim Steele. Thank you.
If Steve McIntyre were to find time and the inclination to deal with this in his analytical manner and co-author a paper with Steele and Amstrup, the polar bears crises could be laid to rest. That would certainly ease the minds of those fearing for the safety of polar bears, I would hope. 😉

ferd berple
July 3, 2013 8:09 am

… by the middle of this century, two-thirds of the polar bears will be gone from their current populations”.
================
Duh! The lifespan of polar bears is 45 years max, so it is quite likely 2/3 of those alive today will be dead in 40 years.
Great article. Hopefully the census bureau will start a catch and release program soon in the local supermarkets to replace that nuisance questionnaire they have you fill out regularly under pain of death or worse – endless hounding phone calls as soon as your sit down to dinner.
Fishermen have relied on catch and release for years. Every time they come home after a “fishing” expedition there is infinite opportunity to tell tales of the humongous fish they caught, only to have to let it go under “catch and release”. Glad to see $cientist$ have caught on. Infinite opportunity to catch and release bears as well as fish.

LamontT
July 3, 2013 8:40 am

Ah computer models. Unfortunately the public isn’t cautious about them and appear to believe that it is possible to accurately predict the future with a computer.
Can a model be helpful for trying to figure out what is going on? Certainly, but they can’t accurately predict the future like a crystal ball.

July 3, 2013 8:48 am

Is it racist of me to ask why the polar bears in the drawings aren’t white?
I don’t think your supermarket analogy is quite right, I see my neighbors a lot more often in my neighborhood than I do at the supermarket, even though I know they must go there at least once a week. The supermarket is a place we migrate to and from, isn’t the place we live, or if you like it is our hunting grounds ,but we always return home.
This way of “counting” reminds me of Bush V.S. Gore where statisticians claimed that Gore must have won, even though two actual counts showed he did not. Then of course Gore later went on to claim that the center of the earth was millions of degrees.

markx
July 3, 2013 8:58 am

commieBob says: July 3, 2013 at 5:01 am
…..and his over sensitive crap-o-meter.
Ah, Bob, you are such a joker! Jim Steele clearly mentions how the bears are really marked, and that “painted cross” is clearly just a tongue in cheek simplified phrase to fit the neat explanatory cartoons … (though, perhaps not simple enough for some).
“….use discreet ear tags and a tattoo under their upper lip in case the tag falls off….”
BTW, Great article, Jim Steele, I enjoyed the read; very educational and very well explained.

juan slayton
July 3, 2013 9:01 am

Dr. Steele,
If I understand correctly, the last PBSG census put the bears into 19 different population groups, and offered a map of their respective areas. The extreme migratory range that you describe in this post raises a question in my mind of how such grouping can have any validity. I’d like to know your opinion.

mpainter
July 3, 2013 9:07 am

When I saw the reference to a USGS report on polar bears, I searched for “USGS report polar bears” on the web. The results astounded me. Their website lists numerous polar bear studies conducted by that agency. Apparently the United States Geological Survey is another public beaurocracy with its snout deep in the trough of public funding of the global warming scam.
The USGS has no business conducting studies in the field of biology. This is not their mission, or should not be. See how the global warming scam grows like some sort of infiltrating tumor and corrupts once respected institutions.

July 3, 2013 9:19 am

Hi Anthony,
Really nice post, thank you for sharing. I grew up in Romania, into a mountain town, where Carpathian bear or brown bear presence is felt almost every day in some areas because of the lack of food, bears come down into the town and they look for food. Unfortunately the main problem remains the decreasing number of them from year to year, even if the authorities shows the situation in a less dramatic shades. Lack of supported projects and low interest to protect them I am sure that the a few years the presence of Carpathian bear will become a rarity.
On Youtube are lots of videos with the bears walking on the streets, especially in Racadau, Brasov.
Best,

Dan Clauser
July 3, 2013 9:20 am

Dr Lurtz,
I found out yesterday at my son’s 2 month exam that vitamin D is not a vitamin, but has been found to be a steroid. Is there anything we’ve been taught that’s true? That’s what we have the Watts and McIntires and Steeles of the world to help us sort through!

Colin
July 3, 2013 9:24 am

How To Lie With Statistics [Paperback]
Darrell Huff (Author), Irving Geis (Illustrator)
This was a mandatory textbook in my Bio-Statistics course while at University. Made me skeptical of every statement saying “x% of people believe…..”
I guess the “Climate Scientists” were a firm believer of this book. Enough said.

July 3, 2013 9:46 am

Brilliant post! Many thanks.

howling winds
July 3, 2013 9:51 am

….I simply wouldn’t trust anything those Inuits said. After all, they are gun owners, hunters, don’t believe in gay marriage, and worst of all, they are creationists..,…

mpainter
July 3, 2013 10:01 am

According to one source, written circa 1980, polar bears migrate with the ice rafting down the east coast of Greenland. Many of these wind up in Iceland, where they raid the farmer’s stock and wind up getting shot. I would wager that any collar on these beasts simply gets discarded, for what farmer wants the eco-police to come snooping around, asking questions and looking for trouble.

Owen in GA
July 3, 2013 10:12 am

commieBob says:
July 3, 2013 at 5:01 am
I haven’t read past the first couple of paragraphs and seen a couple of illustrations. This post set off my crap-o-meter.
… which you then mark by painting a big white cross on their chests.
Polar bears are white folks. Polar bears are always white except when they come out of their dens and are dirty white. You can’t identify them by painting them with white paint. Whoever produced this post clearly isn’t intimately familiar with polar bears.

This is what is known in science as a “thought experiment”. It is used to relate a complicated statistical construct in concrete terms to communicate it to those uninitiated to the scientific technique. The poster used the term “bears” as something that the average reader could relate to. I would think a reasonably intelligent person would have seen that immediately.

SJWhiteley
July 3, 2013 10:15 am

“Is there anything that we have been taught that is correct? I mean anything about anything!”
This is why education [should] teach the fundamentals as the basic ground work to any subject. Statistics is an interesting subject because the nuances of it are not taught in schools, and even in later college, it is misapplied by concentrating on the subject matter (in this case polar bears), rather than the relevance of the statistical methods and results.
To that end, the public believes they have been ‘taught’ something about [polar bears] but in reality they have been told what someone concludes from the conclusion of a statistical study: they have learned nothing.
I’m an engineer, and as part of my current workload, it is analyzing discrete time based and length based data from digital control systems. I don’t consider myself a particular expert on applying (and misapplying) statistical analysis, but simply competent, and can see reasonably well the flaws introduced in these methodologies and the grossly misleading conclusions presented (I’m referring to the original polar bear study, which Jim Steele has done a good job of pointing out the flaws).

thelastdemocrat
July 3, 2013 10:32 am

In many mammal species, as males enter or move along adolescence toward adulthood, and into adulthood, they become less tied to more geographically and socially stable groups. In some species, inter-male aggression drives them out. This is supposed to be a mechanism for promoting genetic heterogeneity. The males drift toward other social groups, and patiently wait to be accepted into the group. Optimistically, they might get to reproduce. The length of time it can take to get adopted into a new social group is suspected to be a form of quarantine – you don’t want a disease in one social group to jump to another; the peripheral male, if diseased, may die before infecting another social group.
The phenomenon is called “peripheral male.”
We often think of some alpha male with his harem in various animal social structures. Well, where are the rest of the males? They either get a place in a social hierarchy, or are socially and geographically peripheral.
If bears have this social structure, then it would be much wiser to tag females and follow them. They may move, but a fair portion of population will be moving in tandem. Some or most males encountered may be under a pattern of quite lengthy undirected wandering.

Allan M
July 3, 2013 10:34 am

commieBob says:
July 3, 2013 at 5:51 am, etc.
Do try to develop a sense of humo(u)r.

Jimbo
July 3, 2013 10:50 am

commieBob says:
July 3, 2013 at 5:01 am
I haven’t read past the first couple of paragraphs and seen a couple of illustrations. This post set off my crap-o-meter.
… which you then mark by painting a big white cross on their chests.
Polar bears are white folks. Polar bears are always white except when they come out of their dens and are dirty white. You can’t identify them by painting them with white paint. Whoever produced this post clearly isn’t intimately familiar with polar bears.

[my bold]
Are you sure polar bears are white?
http://www.polarbearsinternational.org/about-polar-bears/essentials/fur-and-skin

george e. smith
July 3, 2013 11:00 am

Well counting polar bears is pretty easy; same as counting sheep. You see, the sheep crowd together so you can’t tell where one fleece ends, and another begins.
So you get on your knees and look underneath, and count all the feet. Divide by four, and you have your answer.
If you get a remainder, call the vet.

george e. smith
July 3, 2013 11:07 am

I think polar bears are actually black, not white. (under that fur).
The polar bear fur, which is highly prized by steelhead fly tyers, is actually a hollow tube, which gives good thermal insulation. It’s also a good fibre optic light pipe, which conveys solar radiation down to the skin.

Jimbo
July 3, 2013 11:07 am

It’s funny what happens when you actually make a concerted effort to make painstaking observations. The emperor penguin population doubled in Antarctica when satellite imagery was used. Yet just a few years back there were a lot of lies about them being endangered. Bollocks again. Every time you knock down a Warmist zombie it comes right back up.
http://news.discovery.com/animals/emperor-penguins-antarctica-count-120413.htm
http://www.bbc.co.uk/news/science-environment-17692025

Peter Dunford
July 3, 2013 11:14 am

So could we use numbers of tattoo artists as a proxy for numbers of polar bears? I’m guessing polar bears don’t react well to being tattooed.

Alan D McIntire
July 3, 2013 11:23 am

My simple formula of 100%/death rate giving 100/3.1 = 32 + years was implicitly assuming a steady state population. If there WAS a sudden population boom where every mother bear had 2 cubs and they all survived to adulthood, and the original older populatoin had a steady state death rate you could temporarily get 100/2.5 = 40 years, or even 250 years with that 0.4 % death rate- that would mean you had a population explosiion with a large jump in the proportion of juveniles.. That’s what happed to the US population starting in the late 1940 thanks to the baby boom. I suppose now, we’ll get a HIGER than average death rate thanks to baby boomers entering their 60s.

george e. smith
July 3, 2013 11:34 am

“””””……•Scientific Finding. Scientists used to think that polar bears’ hollow hairs acted like fiber optic tubes and conducted light to their black skin. In 1988, Daniel W. Koon, a physicist at St. Lawrence University in Canton, New York, and graduate assistant, Reid Hutchins, proved this false.
Their experiments showed that a one-fifth inch strand of polar bear hair conducted less than a thousandth of a percent of applied ultraviolet light. So, the black skin absorbs very little ultraviolet light. Instead, Koon believes keratin, a basic component of the hair, absorbs the ultraviolet light……”””””
Now you see why you should never believe anything, that starts with: “scientists think”. which essentially means the same thing as “scientists don’t think.”
Both statements, are missing that important caveat : “some”.
Now ask yourself; when was the last time you got out your UV fluorescent “black light”, when you wanted to warm yourself up ?
Now you won’t find AT&T trying to run UV signals, through thousands of miles of fibre optic cables, to get trash to your iThingie.
nanoscopic defects in FO cables scatter short waves, so it doesn’t propagate very far.
So they use longer wavelengths in the 1300 to 1500 region, which scatter much less. Water also absorbs longer wavelengths better than shorter.
So any biological structure made out of organic carbonaceous molecules, is going to have better optical properties, with wavelengths longer than their molecular structures.
So why did these dummies test polar bear fur optics, at UV, instead of visible and near IR.
Incidently, the best FO fibres, are so transparent, at their best wavelength, it would make your head spin.
If the ocean water was as transparent to solar radiation, as long distance FO cables, you would be able to watch the fishes swimming around on the bottom of the Challenger deep.
Well you’d need a telescope too, it’s almost seven miles down there.

mkelly
July 3, 2013 11:55 am

george e. smith says:
July 3, 2013 at 11:00 am
Mr. Smith I always learn or laugh at your posts. Thanks you.

July 3, 2013 12:10 pm

@ Juan Slayton If I understand correctly, the last PBSG census put the bears into 19 different population groups, and offered a map of their respective areas. The extreme migratory range that you describe in this post raises a question in my mind of how such grouping can have any validity.
The population groups are fairly reliable but should not be seen as concrete boundaries. The boundaries are determined following marked bears and determining where the bears are most likely to be found. From a management point of view this is useful. Nonetheless bears do wander outside those boundaries for short periods of time. They are currently re-thinking the boundaries of the north Beaufort Sea population do to better understanding of movement patterns. The bear wandering from Alaska to Greenland is more of an exception than the rule. Still within those defined population boundaries bears are moving large distances in and out of more discreet study areas.

JimS
July 3, 2013 12:10 pm

Why don’t they just listen to the Inuit?

george e. smith
July 3, 2013 12:34 pm

Well, I can’t say, I actually understood Jim Steele’s rationale for how you count bears, based on ideas of their survival rates; but I’ll assume it makes sense to those who do understand it.
But his descriptive sketches, using “brown bears” and painting “white crosses” on them left no doubt, that the idea was to clearly mark them with a contrasting marking. For example if you were marking white horses, you could paint black stripes on them; but with black horses, you would change to white stripes.
See that’s howcome we just don’t remember what the hell color zebras were, before we painted them all.
Now all the National Geographic tourist polar bears I have seen, courtesy of Canon, and PBS, were white with red crosses painted on them.
Now commie bob did say polar bears are white, to make his point that you don’t paint white crosses on those bears, so that’s technically correct; but irrelevant, since Jim’s pictures show his “methodology” bears definitely are not white. I’ll still have to reread, to understand the different scenarios Jim describes.
I’m astonished to learn of the Alaska to Greenland wrong way bear; that’s pretty amazing. I wonder how much of that was by land (ice), and how much by sea

Gary Pearse
July 3, 2013 12:58 pm

I notice, at least, that Drs. Charles Monnett and Jeffrey Gleason who cooked the deaths of umpteen polar bears for the government in Alaska in 2004 to tip the scales against oil exploitation wasn’t quoted.
http://www.alaskadispatch.com/article/alaska-polar-bear-researcher-reprimanded-allowed-return-work
He was reprimanded and then let back on the job. The economic damage done deliberately by these two seems to not have cost them much.

Scott Scarborough
July 3, 2013 1:17 pm

Using these methods it seems that they would get “apparent survival rates” of over 100% many times. That right there, tells you there is something wrong.

Tom Wiita
July 3, 2013 1:25 pm

Some nuggets of information above raise other issues. If a reliable study shows bears average 3,700 miles of travel, and can travel from Alaska to Greenland in one summer, how meaningful can it be to define and worry about sub populations? If they can and do travel thousands of miles to find better hunting, their adaptability means its going to take a lot more adversity than they’ve seen so far to threaten them. Of course most of them don’t travel so far, because they don’t have to, they find plenty of food nearby. But if they need to, they can and do.

July 3, 2013 1:37 pm

george e. smith says:
“See that’s howcome we just don’t remember what the hell color zebras were, before we painted them all.”
That reminds me, I have a pic of my wife & me in Tijuana 20 years ago, sitting on a cart hitched to a zebra. The Mexican’s camera was an actual pinhole camera made from a shoe box. He pulled out the pin for about 5 seconds, put it back, then went into a little shed to develop the B&W film.
It is one of my favorite pictures. But of course, it was a donkey, not a zebra. The Mexican had painted stripes on it for some incomprehensible reason. But its tackiness makes me like the picture even more!☺

Eugene WR Gallun
July 3, 2013 1:39 pm

Yeah, and if you look at the pictures you see WHITE walruses in the background. Wow! My crap-o-meter is just going crazy! Obviously Jim Steele doesn’t know a thing about walruses either!
Eugene WR Gallun

Eugene WR Gallun
July 3, 2013 1:44 pm

Oh, perhaps I should have added — great article.
Eugene WR Gallun

July 3, 2013 1:46 pm

Polar bears are very dangerous predators. Here is a damn interesting article about some explorers who ran into a few.

H.R.
July 3, 2013 1:48 pm

Scott Scarborough says:
July 3, 2013 at 1:17 pm
“Using these methods it seems that they would get “apparent survival rates” of over 100% many times. That right there, tells you there is something wrong.”
======================================================
Great Scott! Zombie Bears!!
Is there nothing CO2 can’t do?!?

July 3, 2013 2:05 pm

This is a very poor use of statistics. The method works when used with a fairly large sample. Because of the random act of sampling, error is unavoidable. The error generally varies as the inverse of the square root of the sample size. Four bears is laughably small. If you want a census of fish, you catch and tag about 200. A year later, another sample of 200 will include some of those you tagged. This will give you an estimate of the population. I won”t go into details here; this can be looked up in an elementary stats text. This four bears notion is about as accurate as those ads from 50 years ago saying that “4 out of 5 doctors recommend” some product. A Ouija board would be just as helpful as four bears.

Duster
July 3, 2013 2:10 pm

commieBob says:
July 3, 2013 at 5:01 am
I haven’t read past the first couple of paragraphs and seen a couple of illustrations. This post set off my crap-o-meter…..

So, based upon not definitely not reading the article, and definitely looking at the cartoons, you commented? Have you considered running for office? You’ll be a natural.
Since you didn’t read it, you probably didn’t notice that the article is about polar bears to begin with. It is about statistical sampling methods, using methods suited to the actual behaviour of the living animals you’re studying, and the results of administrators insisting that reliability tests be ignored after they have already determined on a policy based upon faulty methods. Nor are the cartoons supposed to illustrate polar bears, nor anywhere in the article does anyone claim that any researcher painted white crosses on polar bears.

Craig Bitler
July 3, 2013 2:10 pm

Thanks for your article Jim. About 25 years ago I was doing some research during the summer months south of Churchill, Manitoba and we were not allowed to leave the high-fenced compound we ate and slept in without a loaded slug gun due to the polar bears. Every year the ice on Hudson Bay melts and the bears move onto land to forage until the until the bay freezes again. The is an annual routine and yet there are plenty of bears. I worked as a wildlife biologist for the USFWS for 30 years and I asked a number of the upper level management folks why the bears on the Arctic would go extinct if the ice melted during the summer when their kissing cousins on the Hudson Bay were doing just fine? They all said they had never thought about that.

July 3, 2013 2:31 pm

These frauds really have to be picked apart and the fraudsters prosecuted. This sort of shonky “science” to keep alive the myth of impending doom will continue until actual individuals are actually held accountable and face real jail time. Right now, anything goes. This is not good enough.
Do we really need blood in the streets to put a halt to this crime? I want to see individuals held responsible for their claims that cost societies billions and countless thousands of winter deaths due to fuel poverty. I want to see accountability and jail time for doom-and-gloom prophets and profiteers.

July 3, 2013 3:06 pm

Great post Jim Steele!

“Alexander Feht says: July 3, 2013 at 4:31 am
A demographic study of radio-collared professors should yield even more shocking results.”

There might have been a typo in your statement Alexander. Perhaps you meant
“A demographic study of shock-collared professors should yield even more radio results.”
;->

jono1066
July 3, 2013 3:43 pm

Did someone says polar bears are white ?
I have lead a sheltered life and had been told over the years that they are black in skin colour, it being the hollow fibres of the coat that make them look white.
Perhaps the theoretical researcher shaved an area of fur (with an imaginary root) before applying a white cross

george e. smith
July 3, 2013 3:58 pm

“””””…..
mathman2 says:
July 3, 2013 at 2:05 pm
This is a very poor use of statistics. The method works when used with a fairly large sample. Because of the random act of sampling, error is unavoidable. …..”””””
We seem to have readers, who don’t seem to catch on, unless you rub their noses in it.
Jim Steele presents a model; a concept. So he has a corral; fenced to keep a few cows in. Fat chance the bears will stay in the corral; well we’re talking about polar bears; but we’ll make the bears brown. Well that forces us to paint the walruses white to distinguish them from brown polar bears with toothache. Short on colors so we’ll use white crosses on the brown polar bears, instead of red. Well how do you whip out 200 brown polar bears in a corral the size of a smartphone. Mox nix, we’ll just draw 4 brown polar bears with white crosses, imagine the rest of the 200, while you imagine the brown polar bears are actually black underneath that brown fur, which is actually white like we painted the walruses; which are actually brown; well maybe pink.
Did not Jim’s cartoons present enough of an image of the real model, to let one fill in one’s own numbers or color details.
Now if one yamal tree can make a hockey stick, I think four brown polar bears in a corral, with white crosses on them, is descriptive enough to imagine hordes of them swimming from Alaska to Greenland.
I thought Greenland was in the Atlantic; how did it get over there in the north Pacific, by Alaska.
PS for “swimming” read “hiking”

July 3, 2013 4:33 pm

Tom Trevor says: Is it racist of me to ask why the polar bears in the drawings aren’t white?
Careful I hired an African American art student to do my illustrations. When I specifically asked for polar bear drawing he did a very nice job.
This essay is adapted from a longer chapter filled with polar bear and walrus pictures and illustrations. When I asked my illustrator for these drawing to help visualize mark and recapture, I didn’t specify polar bear. So he gave me what you see. I liked the drawings, and went with them thinking they were a nice contrast and stood out on the printed page.after all it was more about mark and recapture methodology. Coming at the end of the chapter, it seemed most people would not mistake them for polar bears. Little did I know that it would become the focus such efforts to discredit the scientific flaws.
I have learned one thing from the politics of climate change. That when ever some one is incapable of arguing the evidence, they turn to character assassinations. Apparently the truth revealed about the USGS’ bad model is quite threatening.

Owen in GA
July 3, 2013 5:00 pm

mathman2 says:
July 3, 2013 at 2:05 pm
This is a very poor use of statistics. The method works when used with a fairly large sample. Because of the random act of sampling, error is unavoidable. The error generally varies as the inverse of the square root of the sample size. Four bears is laughably small.

WOW! A simple depiction of the concept of the statistical technique causes so much consternation. This whole example was to give the layman an idea of what went into the experimental technique. It was an article written for a wide audience not necessarily fluent in population studies and did a rather good job of it. When writing for an audience with widely divergent backgrounds, the art of simplification is highly necessary. If it gets too much into the technical jargon of a field, it runs into an issue that the same words may mean very different things to a biologist than to a chemist or a statistician.

ferd berple
July 3, 2013 5:31 pm

mathman2 says:
July 3, 2013 at 2:05 pm
This is a very poor use of statistics. The method works when used with a fairly large sample.
==========
the point of the article is that you are sampling more than numbers, because the bears are not geographically confined to the place in which the sample is drawn. there is only limited ability to tell if a bear has died or has simply moved to a different area. so, your statistics can yield nonsensical results by confusing mortality and mobility.

July 3, 2013 9:57 pm

e Smith Well, I can’t say, I actually understood Jim Steele’s rationale for how you count bears, based on ideas of their survival rates; but I’ll assume it makes sense to those who do understand it.
Its not my person rationale, it is the basis for all models, but you seem bent on diverting attention from more serious matters. Wikipedia discusses mark and recapture. Perhaps that will help you understand the basics behind most population models. “The “capture histories” generated are analyzed mathematically to estimate population size, survival, or movement”
http://en.wikipedia.org/wiki/Mark_and_recapture

July 3, 2013 11:01 pm

@ Owen in GA WOW! A simple depiction of the concept of the statistical technique causes so much consternation. This whole example was to give the layman an idea of what went into the experimental technique.
It is indeed a prime example how those whose politic’s are aligned with spreading CO2 fear, are dedicated to obscuring any attempt to explain the science to the public. Not one critic discussed the basics, but all tried desperately to divert our attention elsewhere. Each critic not only accepted the fraudulent claims but they sought to protect them. Now we at least know some of their names and methods, although it is easy to log in under another name.But such is the nature of science and such tactics have bedeviled honest scientific debate for centuries.
When John Muir wrote that glaciers had created Yosemite Valley, he was attacked as an ignorant shepherd who lacked the credentials of a geologist. His main tormentor was chief of the California Geological Survey and Harvard professor Josiah Whitney. Whitney had hitched his authority, fortune and fame to a more catastrophic interpretation. Yet despite Whitney’s lofty credentials, it was the “ignorant shepherd” whose ideas stood the test of time and no one did more for conserving the environment. Muir published in popular magazines and newspapers and eventually caught the world’s attention. We must thank Anthony for maintaining a website that strives to bring science to the people, and allows enough openness so that those who try to obscure the science will expose themselves for what they really are.

July 4, 2013 1:09 am

For clarification, I posted a story about counting sheep and a dog because it was funny and more or less on topic. It was never intended as a comment on the quality of the work of anyone.
It’s a long familiar technique to the analytical chemist, commonly known as ‘isotope dilution’. The analogy we were taught in the 60s was about estimating fish numbers in a pond. You catch a number of fish, mark them in some way, then throw them back. When you resume fishing, the number of marked fish to unmarked fish gives an estimate of total.
In the lab, one adds a measured quantity of radioactive isotopes to a sample of known weight, mixes, separates the element being analysed, then measures radioactivity of the again. It’s a very good method when the element has a convenient isotope.
We don’t have polar bears in the Southern hemisphere, but beware the vicious drop bear.

Don K
July 4, 2013 6:08 am

An excellent article. and well written. I learned a lot.
Am I the only person who actually read the whole thing and found at the end that Jim Steele has a couple of decades of hands-on experience in population studies (albeit of birds, not bears).
If there is any weakness in the essay, it might be in the section on survival rates. I had the same reaction as Alan McIntire. 99.6% survival rate? The Inuit don’t have that or anywhere near that and they can radio for an air drop of food/fuel/medicine should things break badly for them. Very high survival rates seem implausible for large predators living in a hostile and somewhat dangerous environment, no matter how well adapted. Not to mention the issue of idiots with firearms shooting the bears for no very good reason — a problem the Inuit presumably don’t have to anywhere near the same extent.
Overall, it sounds to me like a reasonable take away is that counting polar bears is very difficult and thus estimating population change is hard. Claims that the number of bears is dropping do not stand up well to scrutiny, and Inuit claims that the bears are more numerous than in the recent past seem entirely consistent with the evidence such as it is.

July 4, 2013 7:01 am

@ Don
Several studies of large mammals, marine mammals and Emperor penguin all conclude that high survival rates >90% are necessary for population maintenance due to high mortality of their young. What was so unusual was the one year drop to 77%.

Don K
July 4, 2013 7:47 am

Jim
You’ve had decades to think about this stuff and doubtless know stuff that would take me years to learn. But my gut feeling is that adult survival rates between 90% and 95% seemed likely for a sustaining population of polar bears. That would correspond to an average lifespan of 10-20 years? (13-23 years because we are counting cubs separately from adults?) I could possibly make a better guess if I knew more about the impregnation rates, multiple births, and life expectancy/survival rates of cubs of course. But I imagine, that I’d be wrong no matter how much I “knew”.

Gail Combs
July 4, 2013 3:03 pm

Jim Steele, Thank you for the essay.
It is hard to believe anyone would take the stats. from such mediocre techniques seriously. Unfortunately ClimAstrology will be come a case study for a future edition of ‘How to Lie with Statistics’ Will the 20th century become notorious for the Climate scam where madness infected most of the Universities and Lysenkoism ruled the day?….

FORBES: The Disgraceful Episode Of Lysenkoism Brings Us Global Warming Theory
…Those who promote the theory are favored with billions from government grants and neo-Marxist environmentalist largesse, and official recognition and award. Faked and tampered data and evidence has arisen in favor of the politically correct theory. Is not man-caused, catastrophic global warming now the only theory allowed to be taught in schools in the West?
Those in positions of scientific authority in the West who have collaborated with this new Lysenkoism because they felt they must be politically correct, and/or because of the money, publicity, and recognition to be gained, have disgraced themselves and the integrity of their institutions, organizations and publications….

H.R.
July 4, 2013 7:48 pm

Personally, I’d count polar bear noses and divide by one, but that’s just me. I’m not sure how long I’d last in the business, but I’d guarantee my accuracy up to the time I was eaten.

george e. smith
July 4, 2013 9:35 pm

“””””……
jim Steele says:
July 3, 2013 at 9:57 pm
e Smith Well, I can’t say, I actually understood Jim Steele’s rationale for how you count bears, based on ideas of their survival rates; but I’ll assume it makes sense to those who do understand it.
Its not my person rationale, it is the basis for all models, but you seem bent on diverting attention from more serious matters. Wikipedia discusses mark and recapture. Perhaps that will help you understand the basics behind most population models. “The “capture histories” generated are analyzed mathematically to estimate population size, survival, or movement”…..”””””
Jim,
You have quite mistaken my comments, and my intent.
a) I’m not any wildlife expert, particularly large predators.
b) I’m not a statistician; in over 50 years as a practicing Physicist in industry; statistics has never been used to perform any of my job responsibilities. My use of models, and modeling always produces results that work in practice.
So I only briefly scanned your paper, to try and understand what you were trying to determine. I specifically did not read in detail, to see if I agreed with your methodology. As I said, I accept that persons who DID understand those details probably know it all makes sense; and that was good enough for me.
What I then mainly addressed my attention to, was your pictorial description of the basic methodology; which evidently got some folks riled up on minutiae that had nothing to do with the validity of the study. The fact that your graphic artist colored his bears brown, and walruses white, was a total irrelevancy, as was his only drawing four crossed bears, and in a corral at that. Well he perfectly captured the concept of your study population, and with a humorous twist, that you shared with us. I also liked his “disguised” researchers.
My words were directed to those who thought you only marked 4 bears, and complained of your artists coloring.
No my words were not aimed at diverting attention from the study.
I admit, that I first had this mental picture of Alaska, and Greenland facing each other across a water body so I was wondering about how much of the route would be over ice, versus perhaps swimming. But then I quickly realized I had misplaced Greenland, so the route was different; although I guess the question still remained; did the bear make the entire trip across arctic ocean ice, or did it have to swim some open waters as well.
But nothing in my posts was intended to be critical of your study; and if you took it that way, then please accept my apology. My only criticisms were directed at those who for their own reasons, didn’t want to see your artist’s pictorial representation, as being fully descriptive of the study setup. And my compliments to your artist, for both his sketching talents, and evidently for his sense of humor.

Lewis P Buckingham
July 5, 2013 4:54 am

Still can’t work out why that white crossed black bear is carrying a couple of large leaf like ferns over to the white walruses.
Maybe that bear had left the corral and migrated briefly to Florida.

PiperPaul
July 6, 2013 2:06 pm

“Whoever produced this post clearly isn’t intimately familiar with polar bears.”
I don’t want to be “intimately familiar” with ANY kind of bear.