Size

[brobear]

In each of the three groups ( above ) notice the weight difference between a barely sexually-mature bear ( 5 years old ) and those 10+ years old.

[King Kodiak]

Sept 8, 2020 9:46:08 GMT -5 brobear said:

In each of the three groups ( above ) notice the weight difference between a barely sexually-mature bear ( 5 years old ) and those 10+ years old.

Yeah, huge difference brobear.

[King Kodiak]

How to Measure a Bear's Weight From Its Foot Size

Although zookeepers may have the equipment and controlled circumstances needed to weigh a bear, in the wild you generally need to rely on estimates of weight. You can make a reasonable estimate by looking at the size of its footprints or tracks. The size of a bear's paws, and the size of the prints it leaves, allows you to make a rough estimate of the bear's size, maturity and likely weight. While in bear country, take precautions to avoid provoking a bear into attacking. Be particularly careful when mother bears are with young cubs.

Measure the bear's footprint by laying your tape measure or ruler to the side of the print. Write down the length of the footprint at its longest part, from heel to toe. Also, measure the width of the print.

Compare the length and width measurements. If the length and width are similar, it is likely a footprint from a bear's front paw. If the print is longer than it is wide, it is more likely a back paw print.

Find out what type of bears live in the environment where you found the print. Black bears, for example, live in California and Vermont. Brown bears live in Alaska and other locations throughout North America, Europe and Asia.

Compare the size of the footprint to the usual weight range of a black or brown bear. For a black bear, a front paw print 5 inches long is average, equating to an average weight of between 150 and 175 lbs. A 7-inch front print is from a bigger bear -- 300 to 400 lbs. for a black bear. An average weight for a male brown bear is 500 lbs., with a large male bear weighing up to 800 lbs. Brown bear front tracks are between 6 and 8 inches long -- a 6- to 7-inch front track would likely represent a 400 to 500-lb. bear, while an 8-inch front track would indicate a 700 to 800-lb. animal. Brown bear rear tracks are 12 to 16 inch long, with 16-inch tracks representing the heavier bears.

www.google.com/url?sa=t&source=web&rct=j&url=https://sciencing.com/measure-bears-weight-its-foot-size-10069146.html&ved=2ahUKEwj974Xeu_DrAhUEmlkKHcP4ArgQFjABegQIDxAG&usg=AOvVaw3ctxmXK0_DgaIkxWb8EIpM

[brobear]

Reply #282 contradicts a number of reports I've read saying that the size of a brown bear ( or maybe bears in general ) cannot be determined from footprints nor skull size.

[King Kodiak]

Sept 17, 2020 11:25:44 GMT -5 brobear said:

Reply #282 contradicts a number of reports I've read saying that the size of a brown bear ( or maybe bears in general ) cannot be determined from footprints nor skull size.

Yeah, like it says on that site, that method is just to give a "reasonable estimate" of the bear's weight right on site. Not an exact number.

[King Kodiak]

Population Density and Food Conditions Determine Adult Female Body Size in Brown Bears

Abstract

We investigated growth and determinants of adult female body size in brown bears (Ursus arctos) in 2 study areas in Sweden. Scandinavian female brown bears reached 90% of their asymptotic size at 4.1-4.7 years. Four factors were considered in our analysis of the determinants of adult female size: annual food conditions, population density, multilocus heterozygosity, and yearling body size. Our results suggest that individual body size variation of female brown bears is negatively related to density-dependent factors and positively correlated to density-independent fluctuations in the environment. Density-dependent factors may operate by increasing competition for food, resulting in a decrease in body size. Food resources for brown bears in Sweden fluctuate annually in the boreal forest and influence individual body size. Multilocus heterozygosity and yearling body size were not important in explaining adult size, because initially smaller individuals show compensatory growth when experiencing good food conditions.

Full study here:

academic.oup.com/jmammal/article/87/3/510/897607

[brobear]

en.wikipedia.org/wiki/Subspecies_of_brown_bear

Ecotypes or regional populations

Brown bear size, most often measured in body mass, is highly variable and is correlated to extent of food access. Therefore, bears whose range in areas with access to openings, cover, and moisture or water are on average larger, whereas those bears that range into enclosed forested areas or arid, sparsely vegetated regions, both of which tend to be suboptimal foraging habitat for brown bears, average smaller. The brown bear in northern Europe (i.e., Scandinavia, eastern Europe, western Russia), Yellowstone National Park or interior Alaska seasonally weigh on average between 115 and 360 kg (254 and 794 lb), from mean low adult female weights in spring to male bear mean high weights in fall. Brown bears from the Yukon Delta, interior British Columbia, Jasper National Park and southern Europe (i.e., Spain, the Balkans) can weigh from 55 to 175 kg (121 to 386 lb) on average. These mass variations represent only two widespread subspecies, the grizzly bear in North America and the Eurasian brown bear in Europe. Due to the lack of genetic variation within subspecies, the environmental conditions in a given area likely plays the largest part in such weight variations.

The grizzly is especially variable in size, as grizzlies from the largest populations, i.e. interior Alaska, with the heaviest weights recorded in Nelchina, Alaska, nearly three times heavier in males than the smallest grizzlies from Alberta, Canada's Jasper National Park. Between the sexes, the grizzlies of Nelchina average around 207 kg (456 lb), whereas the Jasper grizzlies averaged about 74 kg (163 lb). The enclosed taiga habitat of Jasper presumably is sub-optimal foraging habitat for grizzlies, requiring them to range widely and feed sparsely, thus reducing body weights and putting bears at risk of starvation, while in surfaces areas in the tundra and prairie are apparently ideal for feeding. Even elsewhere in Alberta, weights averaging more than twice those of Jasper grizzlies have been recorded. A gradual diminishment in body size is noted in grizzly bears from the sub-Arctic zone, from the Brooks Range to the Mackenzie Mountains, presumably because food becomes much sparser in such regions, although perhaps the most northerly recorded grizzly bears ever, in the Northwest Territories, was a large and healthy male weighing 320 kg (710 lb), more than twice as much as an average male weighs near the Arctic Circle. Data from Eurasia similarly indicates a diminished body mass in sub-Arctic brown bears, based on the weights of bears from northern Finland and Yakutia.

Head-and-body length in grizzly bears averages from 1.8 to 2.13 m (5 ft 11 in to 7 ft 0 in) while in Eurasian brown bears it similarly averages from 1.7 to 2.1 m (5 ft 7 in to 6 ft 11 in). Adult shoulder height averaged 95.2 cm (3 ft 1 in) in Yellowstone (for any bear measured five or more years old) and a median of 98.5 cm (3 ft 3 in) (for adults only 10 or more years old) in Slovakia. Standing on its hindlegs, a posture only assumed occasionally, typically-sized brown bears can reportedly range from 1.83 to 2.75 m (6 ft 0 in to 9 ft 0 in) in standing height. Exceptionally large inland specimens have been reported in several parts of North America, Europe, Russia and even Hokkaido. The largest recorded grizzlies from Yellowstone and Washington state both weighed approximately 500 kg (1,100 lb) and eastern European bears have been weighed in Slovakia and Bulgaria of up to 400 kg (880 lb), about double the average weight for male bears in these regions. Among the grizzly and Eurasian brown bear subspecies, the largest reportedly shot from each being 680 kg (1,500 lb) and 481 kg (1,060 lb), respectively. The latter bear, from western Russia, reportedly measured just under 2.5 m (8 ft 2 in) in head-and-body length.

In Eurasia, the size of bears roughly increases from the west to the east, with the largest bears there native to eastern Russia. Even in the nominate subspecies, size increases in the eastern limits, with mature male bears in Arkhangelsk Oblast and Bashkortostan commonly exceeding 300 kg (660 lb). Other bears of intermediate size may occur in inland populations of Russia. Much like the grizzly and Eurasian brown bear, populations of the Ussuri brown bear (U. a. lasiotus) and the East Siberian brown bear (U. a. collaris) may vary widely in size. In some cases, the big adult males of these populations may have matched the Kodiak bear in size. East Siberian brown bears from outside the sub-Arctic and mainland Ussuri brown bears average about the same size as the largest-bodied populations of grizzly bears, i.e. those of similar latitude in Alaska, and have been credited with weights ranging from 100 to 400 kg (220 to 880 lb) throughout the seasons. On the other hand, the Ussuri brown bears found in the insular population of Hokkaido are usually quite small, usually weighing less than 150 kg (330 lb), exactly half the weight reported for male Ussuri brown bears from Khabarovsk Krai. This is due presumably to the enclosed mixed forest habitat of Hokkaido. A similarly diminished size has been reported in East Siberian brown bears from Yakutia, as even adult males average around 145 kg (320 lb), thus about 40% less than the average weight of male bears of this subtype from central Siberia and the Chukchi Peninsula.

In linear measurements and mean body mass, several subspecies may vie for the title of smallest subtype, although thus far, their reported body masses broadly overlaps with those of the smaller-bodied populations of Eurasian brown and grizzly bears. Leopold (1959) described the now-extinct Mexican grizzly bear that, according to Rausch (1963), as the smallest subtype of grizzly bear in North America, although the exact parameters of its body size are not known today.Bears of the Syrian subspecies (U. a. syriacus) will reportedly weigh around 100 to 160 kg (220 to 350 lb) in adulthood. The Himalayan brown bear (U. a. isabellinus) is another rival for the smallest subspecies; in Pakistan, this subtype averages about 70 kg (150 lb) in females and 135 kg (298 lb) in males. Himalayan brown bear females were cited with an average head-and-body length of merely 1.4 m (4 ft 7 in). Brown bears of the compact Gobi Desert population, which is not usually listed as a distinct subspecies in recent decades, weigh around 90 to 138 kg (198 to 304 lb) between the sexes, so they are similar in weight to bears from the Himalayas and even heavier than grizzlies from Jasper National Park. However, the Gobi bear has been reported to measure as small as 1 m (3 ft 3 in) in head-and-body length, which, if accurate, would make them the smallest known brown bear in linear dimensions. These smallest brown bear subtypes are characteristically found in "barren-ground" type habitats, i.e. sub-desert in bears from the Syrian subspecies and the Gobi subtype and arid alpine meadow in Himalayan brown bears.

The largest subspecies are the Kodiak bear (U. a. middendorffi) and the questionably-distinct peninsular giant bear or coastal brown bear (U. a. gyas). Also the extinct California grizzly bear (U. a. californicus) was rather large. Once mature, the typical female Kodiak bear can range in body mass from 120 to 318 kg (265 to 701 lb) and from sexual maturity onward, males range from 168 to 675 kg (370 to 1,488 lb). According to the Guinness Book of World Records the average male Kodiak bear is 2.44 m (8 ft 0 in) in total length (head-to-tail) and has a shoulder height of 1.33 m (4 ft 4 in). When averaged between their spring low and fall high weights from both localities, males from Kodiak island and coastal Alaska weighed from 312 to 389 kg (688 to 858 lb) with a mean body mass of 357 kg (787 lb) while the same figures in females were 202 to 256 kg (445 to 564 lb) with a mean body mass of 224 kg (494 lb). By the time they reach or exceed eight to nine years of age, male Kodiak bears tend to be much larger than newly mature six-year-old males, potentially tripling their average weight within three years' time, and can expect to average between 360 and 545 kg (794 and 1,202 lb). The reported mean adult body masses for both sexes of the polar bear are very similar to the peninsular giant and Kodiak bears. Due to their roughly corresponding body sizes, the two subtypes and the species can both legitimately be considered the largest living member of the bear family Ursidae and the largest extant terrestrial carnivores. The largest widely accepted size for a wild Kodiak bear, as well as for a brown bear, was for a bear killed in English Bay on Kodiak Island in fall 1894 as several measurements were made of this bear, including a body mass of 751 kg (1,656 lb), and a hind foot and a voucher skull were examined and verified by the Guinness Book of World Records. Claims have been made of larger brown bears, but these appear to be poorly documented and unverified and some, even if recited by reputable authors, may be dubious hunters' claims.

The largest variety of brown bear from Eurasia is the Kamchatkan brown bear (U. a. beringianus). In the Kamchatkan brown bears from past decades, old males have been known to reach a body mass of 500–685 kg (1,102–1,510 lb) by fall, putting the subtype well within Kodiak bear sizes and leading it to be considered the largest of the extant Russian subtypes. However, a diminishment in body size of U. a. berigianus has been noted, mostly likely in correlation with overhunting. In the 1960s and 1970s, most adult Kamchatkan brown bears weighed merely between 150 and 285 kg (331 and 628 lb); however, mean weights of mature male bears have been reported as averaging 350 to 450 kg (770 to 990 lb) in 2005.

[brobear]

Posted by Polar on Wildfact: Evidence for the greater predatory habits of ancient brown bears isn't only located in true anecdotes, but also in physical evidence.

There have been reports of bear-bones, dated two centuries ago, that have a higher concentration of nitrogen: nitrogen-15. N-15 is found in high amounts in carnivores/meat-eating animals, regardless of species.

So it is a proven fact that bears were more carnivorous back then without major human intervention.

But like the situation with Bengal Tigers, how do we really know that brown bears are getting smaller (polar bears sure are)? Bengal tigers in some populations were smaller at the turn of the 20th century, and now they are larger in the same areas. Vice versa in other populations of tigers.

Some brown bear populations have stayed the same size; namely the Rockies, Inland tundra, Kodiak, and Gobi grizzlies. Some populations have grew larger; Alberta, Northwest Pacific, and Scandinavian grizzlies. Some populations grew smaller; the Siberian, Californian, Mexican, and mainland European grizzlies.

Notice that the brown bears that became smaller lived in vast and diverse environments with plenty of prey, not just in number of prey but in the size of prey as well. The ones who grew larger or stayed the same size didn't have the same prey situation or geographical diversity.

Tigers grow largest in marshlands, and lands that have forests, grasslands, and marshes combined; diversity of prey and geography.

Coincidence?

Not at all.

[brobear]

I'm sure that I have this posted here ( somewhere ) but after ( hours - days ) searching, I finally found it over in Wildfact by your's truly.

About those outlaw grizzlies, the cattle and sheep killers of the American West.

Notorious Grizzly Bears by W.P. Hubbard - 1960 - Pelage and Character - Weight.

A safe estimate of the average weight of adult grizzlies in our western states would be about eight hundred and fifty pounds. This conclusion results from a careful check on grizzlies killed and weighed by numerous hunters, trappers, and old-time bear men. Nevertheless, there are exceptions. Several outlaw grizzlies investigated were known to have weighed over one thousand pounds.

( These outlaw grizzlies were hunted and killed before the Boone and Crockett Club established the idea of preserving bear skulls ). 
 
*Average historical grizzly of the American West: 850 pounds.

[brobear]

By Polar ( Wildfact )...
I remember some old articles and some posters from AvA/ShaggyBoard/CarnivoraForum forums stating that the California grizzly produced plenty of giant specimens all more than 1000 pounds in size, vastly unlike grizzlies of other areas.

Could this be because of the vast, huge abundance of large prey (mountain sheep/large deer/bison), and the fact that American brown bears were more predatory back then?

Kodiak bears become large because of winning intraspecific fights (with their already good genes) among rival males, thus acquiring all of the food routes and areas (most notably, salmon). But the California grizzly seems more of a mystery; it seems as if rival males barely fought with each other unlike their other brown bear cousins.

Ancient California looked like the perfect hospitable place for large animals, for sure! 
 
Evidence for the greater predatory habits of ancient brown bears isn't only located in true anecdotes, but also in physical evidence.

There have been reports of bear-bones, dated two centuries ago, that have a higher concentration of nitrogen: nitrogen-15. N-15 is found in high amounts in carnivores/meat-eating animals, regardless of species. 
 
So it is a proven fact that bears were more carnivorous back then without major human intervention.

But like the situation with Bengal Tigers, how do we really know that brown bears are getting smaller (polar bears sure are)? Bengal tigers in some populations were smaller at the turn of the 20th century, and now they are larger in the same areas. Vice versa in other populations of tigers.

Some brown bear populations have stayed the same size; namely the Rockies, Inland tundra, Kodiak, and Gobi grizzlies. Some populations have grew larger; Alberta, Northwest Pacific, and Scandinavian grizzlies. Some populations grew smaller; the Siberian, Californian, Mexican, and mainland European grizzlies.

Notice that the brown bears that became smaller lived in vast and diverse environments with plenty of prey, not just in number of prey but in the size of prey as well. The ones who grew larger or stayed the same size didn't have the same prey situation or geographical diversity.

Tigers grow largest in marshlands, and lands that have forests, grasslands, and marshes combined; diversity of prey and geography.

Coincidence?

Not at all.

[tom]

Nov 1, 2020 1:38:58 GMT -5 brobear said:

I'm sure that I have this posted here ( somewhere ) but after ( hours - days ) searching, I finally found it over in Wildfact by your's truly.

About those outlaw grizzlies, the cattle and sheep killers of the American West.

Notorious Grizzly Bears by W.P. Hubbard - 1960 - Pelage and Character - Weight.

A safe estimate of the average weight of adult grizzlies in our western states would be about eight hundred and fifty pounds. This conclusion results from a careful check on grizzlies killed and weighed by numerous hunters, trappers, and old-time bear men. Nevertheless, there are exceptions. Several outlaw grizzlies investigated were known to have weighed over one thousand pounds.

( These outlaw grizzlies were hunted and killed before the Boone and Crockett Club established the idea of preserving bear skulls ). 
 
*Average historical grizzly of the American West: 850 pounds.

What is the average weight of Grizzlies today say the Yellowstone variety? Were talking adult males of course.

[brobear]

Nov 1, 2020 7:24:27 GMT -5 tom said:

Nov 1, 2020 1:38:58 GMT -5 brobear said:

I'm sure that I have this posted here ( somewhere ) but after ( hours - days ) searching, I finally found it over in Wildfact by your's truly.

About those outlaw grizzlies, the cattle and sheep killers of the American West.

Notorious Grizzly Bears by W.P. Hubbard - 1960 - Pelage and Character - Weight.

A safe estimate of the average weight of adult grizzlies in our western states would be about eight hundred and fifty pounds. This conclusion results from a careful check on grizzlies killed and weighed by numerous hunters, trappers, and old-time bear men. Nevertheless, there are exceptions. Several outlaw grizzlies investigated were known to have weighed over one thousand pounds.

( These outlaw grizzlies were hunted and killed before the Boone and Crockett Club established the idea of preserving bear skulls ). 
 
*Average historical grizzly of the American West: 850 pounds.

What is the average weight of Grizzlies today say the Yellowstone variety? Were talking adult males of course.

From our "Weight Collection" - Average fully grown male Yellowstone grizzly (9 years+) - 470 pounds.
Average fully grown female Yellowstone grizzly (7 years+) - 305 pounds.
However, the largest inland grizzly skull to date is a "found" skull from those historical times. The two smallest grizzly populations ( of the lower 48 ) were the Rocky Mountain grizzlies ( like the Yellowstone bears ) and the Mexican grizzly. Those old "bison hunters" of the prairie were big bears, as were the California grizzlies. When people began killing off the bison, the bear's continued their high-protein diet on sheep, cattle, and other livestock. 

[tom]

Interesting.. so the Historical Grizzlies of the 1800's were close to twice the weight of todays Bears. The Historical Grizzlies were as you guys have pointed out in the past were likely more of a meat eater due to the more abundant game animals?

[brobear]

Nov 1, 2020 7:55:46 GMT -5 tom said:

Interesting.. so the Historical Grizzlies of the 1800's were close to twice the weight of todays Bears. The Historical Grizzlies were as you guys have pointed out in the past were likely more of a meat eater due to the more abundant game animals?

Reply #289: coincidentally I just copied this from Wildfact yesterday. 
 
*I remember ( was it Wolverine or Grizzlyclaws ) had stated that the historical grizzly was about 80% carnivore and 20% vegetarian. Just the opposite today.

[OldGreenGrolar]

Nov 1, 2020 8:04:32 GMT -5 brobear said:

Nov 1, 2020 7:55:46 GMT -5 tom said:

Interesting.. so the Historical Grizzlies of the 1800's were close to twice the weight of todays Bears. The Historical Grizzlies were as you guys have pointed out in the past were likely more of a meat eater due to the more abundant game animals?

Reply #289: coincidentally I just copied this from Wildfact yesterday. 
 
*I remember ( was it Wolverine or Grizzlyclaws ) had stated that the historical grizzly was about 80% carnivore and 20% vegetarian. Just the opposite today.

That historical grizzly also hunted bisons more than the extant grizzly bear today.

[tom]

Nov 1, 2020 8:34:04 GMT -5 OldGreenGrolar said:

Nov 1, 2020 8:04:32 GMT -5 brobear said:

Reply #289: coincidentally I just copied this from Wildfact yesterday. 
 
*I remember ( was it Wolverine or Grizzlyclaws ) had stated that the historical grizzly was about 80% carnivore and 20% vegetarian. Just the opposite today.

That historical grizzly also hunted bisons more than the extant grizzly bear today.

Well.... part of that is because at one point during the mid to late 1800's there were over 40 million Bison roaming the plains from Montana to Mexico. Nowadays Yellowstone might be the only place a Grizzly would kill a Bison (if he's lucky). 

[brobear]

Quote: Nowadays Yellowstone might be the only place a Grizzly would kill a Bison (if he's lucky).

A bison cow or a calf is taken on very rare occasion. More often, the grizzlies of Wyoming and Montana feed on bison carcasses of those who did not survive the Winter and, of course, wolf kills. A large boar Rocky Mountain grizzly big enough to go head-to-head with a bull bison is uncommon to say the least. In fact, I seriously believe that any fight between a bear and a bull bison ( including the historical grizzly ) is initiated by the bull bison in defense of the cows and calves.

[theundertaker45]

Hunt of an enormously huge Kodiak bear; he was weighed at 1417lbs after blood loss which means that his live weight would have been ~1450lbs (658kg); around the belly he had a circumference of 94 inches (239cm) and his total length from nose to tail was ~109 inches (~277cm).


"They kept saying it could be the biggest bear they had ever taken; so we figured out a way to get it loaded whole and took it back to the lodge. They flew in a hanging scale so we could weigh him. After gallons of blood loss he weighed 1,417 pounds. He would have been close to 1,450 pounds while alive. His hide squared 10’4”. He was 7’10” around the belly and 9’1” nose to tail."


miaanstine.com/2014/11/11/archery-alaskan-brown-bear-hunt/


Credit goes to "Shadow" from "Wildfact" where I found it.

[brobear]

Quote: They flew in a hanging scale so we could weigh him. After gallons of blood loss he weighed 1,417 pounds. He would have been close to 1,450 pounds while alive. His hide squared 10’4”. He was 7’10” around the belly and 9’1” nose to tail.

*Perhaps the biggest bear killed with bow and arrows.  Nice find. 

[theundertaker45]

brobear

The hunter also said that his conventional bow for grizzlies was too small; he eventually used a model designed for the hunt of cape buffaloes and other huge bovids.