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Grizzlies moving North

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Old Thursday 26th December 2019, 20:58   #1
andyadcock
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Grizzlies moving North

https://www.bbc.co.uk/news/blogs-new...where-50810268
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Old Friday 27th December 2019, 06:35   #2
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I'll tell you one thing it will mean: more Polar Bear/Grizzly hybrids which can only be a bad thing for PB,which won't be the first species to be hybridised out of existence when pressured by another.....

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Old Friday 27th December 2019, 12:38   #3
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I'll tell you one thing it will mean: more Polar Bear/Grizzly hybrids which can only be a bad thing for PB,which won't be the first species to be hybridised out of existence when pressured by another.....

John
So on a species protection level, should wandering Grizzlies be controlled a la Ruddy Duck?
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Old Friday 27th December 2019, 12:44   #4
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So on a species protection level, should wandering Grizzlies be controlled a la Ruddy Duck?
Do you know I can't decide. It would have to be on an ongoing basis until the world cools again, and for that matter one would have to consider whether the Southern edge of the Grizzlies' range was chasing them up so they also had nowhere to go.... It's too difficult for a quick answer, but a part of it might be that I suspect even without Grizzly pressure global warming will see off the Polar Bear - so it would be immoral to place downward pressure on the Grizzlies anyway.

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Old Friday 27th December 2019, 19:08   #5
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My understanding is that grizzly and polar bears overlapped ranges in parts of the Arctic since forever (that is 19. century Western explorers).

There should be interesting things going in very High Arctic, where wildlife should move in and spread in areas which were previously dead ice. Unfortunately, these places are not as accessible as the southern edge of the Arctic. Nor they can be used to get more subsidies for photovoltaic panels or convertible cars.
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Old Sunday 29th December 2019, 07:51   #6
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My understanding is that grizzly and polar bears overlapped ranges in parts of the Arctic since forever (that is 19. century Western explorers).

There should be interesting things going in very High Arctic, where wildlife should move in and spread in areas which were previously dead ice. Unfortunately, these places are not as accessible as the southern edge of the Arctic. Nor they can be used to get more subsidies for photovoltaic panels or convertible cars.
Maybe in parts, but what we are heading for is all, since the bears will be unable to use the permanent ice as a separating refuge.

It depends what you call interesting. Yes colonisation by more Southern species will be enabled on some of the land: but receding and eventual removal of the permanent ice will negatively affect seals, Polar Bears and perhaps Arctic Foxes.

Possibly Arctic Fox will endure as an island species in a few places but most likely it will be outcompeted by North moving Red Foxes elsewhere. The bears I reckon have had it. I've no idea how many of the seals can convert to littoral rather than ice breeding or in what numbers. Cetaceans may gain - or some species may.

Overall that seems more sad than interesting.

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Old Sunday 29th December 2019, 10:24   #7
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That's a shame - I'm sure the Polar Bears could survive, if only they were able to get subsidies for their photovoltaic panels and convertible cars.


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Old Monday 30th December 2019, 00:24   #8
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Actually modeling of Polar Bear distribution in future has already been done. The population will shrink ca 30% until 2050 basing on climate warming not being stopped. Fits the Vulnerable status, a step lower than Endangered and less than many animals threatened by deforestation or poaching.

This had little interest to innumberable journalists and activists suggesting they will go extinct.
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Old Monday 30th December 2019, 17:02   #9
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Actually modeling of Polar Bear distribution in future has already been done. The population will shrink ca 30% until 2050 basing on climate warming not being stopped. Fits the Vulnerable status, a step lower than Endangered and less than many animals threatened by deforestation or poaching.

This had little interest to innumberable journalists and activists suggesting they will go extinct.
Well, I'm always in the market for good news, but I'm awfully familiar with models that don't take any, or sufficient, account of what turn out to be major factors (often because "we can't model that"). So I'd be interested to know which of the following were included as factors in the model:

Ice extent/duration each year including ability to bear weight of bear

Maximum distance a Polar Bear can swim (and effect on this of increasingly violent weather events)

Effect of changes of ice cover on prey availability due to effect on prey breeding, including not only total biomass but localisation of populations

Effect of hybridisation in the event of the whole Arctic landmass becoming available habitat to Grizzlies (hint: biggest population normally wins these)

Effect of predation on bears making more long swims than in the past by e.g. Orcas

Availability of snow dens for Polar Bear breeding

Infanticide by male bears confined in smaller territories by reduced ice as well as reduced prey availability

Fragmentation of populations leading to local extinctions (and more permanent separation of remainder as a result)

I also seem to remember hearing that Polar Bears have the highest levels of PCBs of any animal apart from St Lawrence Seaway Belugas and that this is held to have an effect on breeding success. Is that getting worse or better?

Finally, all the news is of climate change happening faster and more violently than anyone expected (or modelled, surprise surprise): does that in itself mean Polar Bear population modelling should be revisited rapidly?

I look forward to hearing all included, no problems.

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Old Monday 30th December 2019, 23:21   #10
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I also seem to remember hearing that Polar Bears have the highest levels of PCBs of any animal apart from St Lawrence Seaway Belugas and that this is held to have an effect on breeding success. Is that getting worse or better?
The North Atlantic inshore Orcas are even worse off - now so heavily loaded they are sterile and functionally extinct already; no calves born for over 23 years

https://www.theguardian.com/environm...xic-pollutants
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Old Tuesday 31st December 2019, 15:20   #11
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You got a positive piece of news that an animal which was officially endangered few decades ago is expanding its range, and you keep looking for a negative edge of it.

For the sake of saying the obvious:

Climate science is in huge conflict of interest. It was an obscure, niche discipline. Currently it gets money and prominence exclusively because climate change is supposed to be dangerous. Unlike many fields of research, climate modeling is very conditional on one type of results. So the field is under huge pressure to find a negative or catastrophic twist of the findings.

Climate field is dominated by large companies, which hope to sell technologies uncompetitive otherwise. They aim for governmennt subsidies. Government budgets are fixed. So money for fighting climate change will be in large part taken away from habitat conservation, old age pensions, ailing infrastructure, education, medicine, salaries of public workers etc.
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