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Post by Gorilla king on Jun 26, 2021 9:53:17 GMT -5
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Post by Gorilla king on Jun 26, 2021 10:06:59 GMT -5
White-beaked dolphins trapped in the ice and eaten by polar bearsPolar bears (Ursus maritimus) depend on sea ice, where they hunt ice-associated seals. However, they are opportunistic predators and scavengers with a long list of known prey species. Here we report from a small fjord in Svalbard, Norwegian High Arctic, a sighting of an adult male polar bear preying on two white-beaked dolphins (Lagenorhynchus albirostris) on 23 April 2014. This is the first record of this species as polar bear prey. White-beaked dolphins are frequent visitors to Svalbard waters in summer, but have not previously been reported this far north in early spring. We suggest they were trapped in the ice after strong northerly winds the days before, and possibly killed when forced to surface for air at a small opening in the ice. The bear had consumed most parts of one dolphin. When observed he was in the process of covering the mostly intact second dolphin with snow. Such caching behaviour is generally considered untypical of polar bears. During the following ice-free summer and autumn, at least seven different white-beaked dolphin carcasses were observed in or near the same area. We suggest, based on the area and the degree to which these dolphins had decayed, that they were likely from the same pod and also suffered death due to entrapment in the ice in April. At least six different polar bears were seen scavenging on the carcasses. www.researchgate.net/publication/277885286_White-beaked_dolphins_trapped_in_the_ice_and_eaten_by_polar_bears
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Post by Gorilla king on Jun 26, 2021 10:13:48 GMT -5
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Post by Gorilla king on Jun 26, 2021 10:15:40 GMT -5
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Post by oldindigosilverback on Jun 26, 2021 22:31:17 GMT -5
The older the polar bear, the more yellow his fur gets.
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Post by Gorilla king on Jun 27, 2021 10:09:34 GMT -5
Seals killed by polar bears in the Canadian high artic:
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Post by Montezuma on Jun 28, 2021 16:41:05 GMT -5
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Post by Gorilla king on Jun 28, 2021 19:30:12 GMT -5
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Post by Gorilla king on Jun 28, 2021 19:34:33 GMT -5
Dietary habits of polar bears in Foxe Basin, Canada: Possible evidence of a trophic regime shift mediated by a new top predator
Abstract
Polar bear (Ursus maritimus) subpopulations in several areas with seasonal sea ice regimes have shown declines in body condition, reproductive rates, or abundance as a result of declining sea ice habitat. In the Foxe Basin region of Nunavut, Canada, the size of the polar bear subpopulation has remained largely stable over the past 20 years, despite concurrent declines in sea ice habitat. We used fatty acid analysis to examine polar bear feeding habits in Foxe Basin and thus potentially identify ecological factors contributing to population stability. Adipose tissue samples were collected from 103 polar bears harvested during 2010–2012. Polar bear diet composition varied spatially within the region with ringed seal (Pusa hispida) comprising the primary prey in northern and southern Foxe Basin, whereas polar bears in Hudson Strait consumed equal proportions of ringed seal and harp seal (Pagophilus groenlandicus). Walrus (Odobenus rosmarus) consumption was highest in northern Foxe Basin, a trend driven by the ability of adult male bears to capture large-bodied prey. Importantly, bowhead whale (Balaena mysticetus) contributed to polar bear diets in all areas and all age and sex classes. Bowhead carcasses resulting from killer whale (Orcinus orca) predation and subsistence harvest potentially provide an important supplementary food source for polar bears during the ice-free period. Our results suggest that the increasing abundance of killer whales and bowhead whales in the region could be indirectly contributing to improved polar bear foraging success despite declining sea ice habitat. However, this indirect interaction between top predators may be temporary if continued sea ice declines eventually severely limit on-ice feeding opportunities for polar bears.
www.researchgate.net/publication/305930165_Dietary_habits_of_polar_bears_in_Foxe_Basin_Canada_Possible_evidence_of_a_trophic_regime_shift_mediated_by_a_new_top_predator
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Post by Montezuma on Jun 30, 2021 9:38:56 GMT -5
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Post by tyrannosaurs on Jul 6, 2021 16:03:05 GMT -5
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Post by tyrannosaurs on Jul 30, 2021 15:48:09 GMT -5
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Post by Gorilla king on Jul 30, 2021 16:49:02 GMT -5
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Post by Gorilla king on Jul 30, 2021 17:15:51 GMT -5
Polar Bear Predation on Beluga in the Canadian Arctic
... The consumption of other prey species, including harp seal, beluga whale, and walrus, suggests opportunistic foraging and locally variable availability. Scavenging on beluga whales, for example, has been recorded across the Arctic (Freeman 1973;Heyland and Hay 1976;Rugh and Shelden 1993). Similarly, walrus has been detected in the diets of polar bears in Foxe Basin and Gulf of Boothia (Thiemann et al. 2007(Thiemann et al. , 2008Galicia et al. 2016) and bears have been observed both scavenging and actively hunting walrus throughout the High Arctic and Chukchi Sea (Calvert and Stirling 1990;Kochnev 2006). ...
... Sporadic dietary shifts in polar bears may be a consequence of ephemeral prey availability and opportunistic foraging (e.g., Galicia et al. 2016). For instance, the observed decrease in bearded seal and increase in beluga consumption in 2004 and 2005 may be related to local entrapment of beluga whales (Freeman 1973;Heide-Jørgensen et al. 2002) that overwinter in parts of Hudson Bay (S. Ferguson, unpublished data) (Luque and Ferguson 2010). ...
... (this report), 9) belugas in November 1966 (Freeman 1968), and 10) belugas in March 1970 (Freeman 1973) andin May 1999 (this report). ...
... Interviews of hunters from Grise Fiord, the only village in Jones Sound, in 1993 indicate that no beluga entrapments were known to have occurred in Jones Sound between 1967 and 1993 and no narwhal entrapments have ever been found in Jones Sound (Stewart et al. 1995). Freeman (1973) also reported predation by polar bears on entrapped whales in March 1970 in Jones Sound.
... Throughout their range, their primary prey is ringed seals (Pusa hispida), accounting for up to 83% of the diet Sciullo et al. 2017). Polar bears also prey on bearded seals (Erignathus barbatus), harp seals (Pagophilus groenlandicus), harbor seals (Phoca vitulina), hooded seals (Cystophora cristata), Fig. 13.1 Image from a global positioning system (GPS)-equipped video camera collar on an adult female polar bear while eating a ringed seal on the sea ice of the Beaufort Sea (Pagano et al. 2018) 248 A. M. Pagano walruses (Odobenus rosmarus), beluga whales (Delphinapterus leucas), and narwhals (Monodon monoceros) (Freeman 1973;Calvert and Stirling 1990;Smith and Sjare 1990;Mckinney et al. 2013). Ringed seals are the smallest (up to 100 kg prior to breeding) and most abundant seal in the Arctic (Hammill 2009). ...
... Previous reports of polar bear scarring on beluga have been reported in Cunningham Inlet (Heyland & Hay, 1976;Smith, 1985;Smith & Sjare, 1990). Polar bears attack as belugas surface and often inflict the injuries on the dorsal body regions (Freeman, 1973;Heyland & Hay, 1976;Smith & Sjare, 1990). We excluded these scars from our individual rake mark total by comparing them to documented cases (e.g., Heyland & Hay, 1976). ...
... comm.). Polar bears (Ursus maritimus) also prey on belugas to a limited extent (Freeman 1973;Smith 1985;Smith and Sjare 1990) but it is not clear how important that source of predation is to Cumberland Sound belugas. ...
... Seven whale species are among the reported species of prey and food known to have been eaten by polar bears (Derocher 2012). The two smaller of these whale species, white whales (Delphinapterus leucas) and narwhals (Monodon Monoceros), are hunted by the bears in some circumstances (Freeman 1973;Smith & Sjare 1990). Five other species, all of them too large to be prey, have been observed scavenged by polar bears. ...
www.researchgate.net/publication/273380115_Polar_Bear_Predation_on_Beluga_in_the_Canadian_Arctic
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Post by Gorilla king on Jul 30, 2021 18:55:47 GMT -5
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Post by Gorilla king on Jul 30, 2021 19:00:36 GMT -5
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Post by tyrannosaurs on Jul 30, 2021 20:24:49 GMT -5
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Post by Gorilla king on Jul 30, 2021 20:57:17 GMT -5
But where in this link does it talk about that 2000 kg range? I dont see it anywhere. Dont get me wrong, i believe a polar bear is capable of killing a 2000 kg walrus which would be a Pacific walrus, (Odobenus rosmarus divergens), but i just never seen an actual account of this, you get my point? As shown at reply #24 though, a polar bear has killed the smaller subspecies Atlantic walrus, (Odobenus rosmarus rosmarus), which weights up to about 3300 lbs.
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Post by tyrannosaurs on Jul 31, 2021 6:10:08 GMT -5
Look at the Alaska fish and game and the big game book I showed, it clearly says some Walruses can weigh more than 2000 kg' (the big game book says that there are estimates of upto 3500 pounds). If a polar bear can kill such animals, why is 2000 kg' out of range?
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Post by Gorilla king on Jul 31, 2021 6:22:45 GMT -5
Look at the Alaska fish and game and the big game book I showed, it clearly says some Walruses can weigh more than 2000 kg' (the big game book says that there are estimates of upto 3500 pounds). If a polar bear can kill such animals, why is 2000 kg' out of range? Yes of course, we know walruses can reach 2000 kg, but that does not mean that polar bears go for those. Just because an animal reaches certain weight, it does not mean its a prey item.
Like i said before, i think a polar bear is capable, we just dont have any actual accounts of this. We only have an account shown above of a polar bear killing a large adult male Atlantic walrus, (Odobenus rosmarus rosmarus), no weight stated, but the max weight for this subspecies is 3300 lbs.
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