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The vast majority is plant matter. It wastes a lot of energy to chase prey. Plants don't move much. Last I read it was on the order of 80% plants, with a lot

The vast majority is plant matter. It wastes a lot of energy to chase prey. Plants don't move much. Last I read it was on the order of 80% plants, with a lot of insects being most of the meat.

samizdis 5y ago
You may be right that the majority is plant matter, but in salmon season bears gather at salmon runs and waste little energy in snatching fish as they leap up the cascades. See [1]. (Although individual bears do compete for the best fishing spots, they are in a "fish in a barrel" situation when they get one. They don't have to chase anything, just grab and chew.) [1] https://explore.org/livecams/brown-bears/brown-bear-salmon-cam-brooks-falls https://explore.org/livecams/brown-bears/brown-bear-salmon-c... Edit to add: Here's an article [2] from 2018, How many salmon will a bear eat? Excerpt: Adult male bears on Kodiak ate the most salmon on average, consuming an incredible 6,146 pounds (2,788 kg) per bear per year! Adult females ate 3,007 pounds (1,364 kg). Salmon consumption varied among subadult bears, independent juvenile bears between 2.5 and 5.5 years old. Subadult females ate 1,248 pounds (566 kg) while subadult males ate 1,305 pounds (592 kg) of salmon per bear per year. [2] https://medium.com/@exploreorg/how-many-salmon-will-a-bear-eat-94d3d212f178 https://medium.com/@exploreorg/how-many-salmon-will-a-bear-e...
- nradov 5y ago
  The bears catch so many salmon on some rivers that they eat only the most nutritious parts and leave the rest of the carcass for scavengers.
  - AlbertCory 5y ago
    Correct. See my post and [1]. I saw this behavior myself. It's not just standing and snatching fish out of the stream, though. Most bears have to chase the fish and try to catch them, often failing. [1] https://photos.app.goo.gl/mXMHAjDyQNDjFqjw8 https://photos.app.goo.gl/mXMHAjDyQNDjFqjw8
- mtnGoat 5y ago
  costs a lot to feed bears. this years salmon price is estimated at $14-20\lb. if we take the average, a bear eats more then $100k a year worth of salmon.
  - AlbertCory 5y ago
    It's cheaper when you buy it near the source.
    - mtnGoat 5y ago
      True, and probably cheaper buying in that kind of bulk. Still an impressive amount of fish.
- monocasa 5y ago
  Also, breaking down plant matter is very energy intensive. Salmon is very close to what animals need, sort of by definition.
Turing_Machine 5y ago
While that is true for inland brown/grizzly bears, the coastal brown bears under discussion in this article eat huge quantities of spawning salmon during the summer and early fall. They get much larger and much fatter than the inland bears as a result.
- celrod 5y ago
  More than 20% for many inland grizzly bears, e.g. Yellowstone: Approximately 45 ± 22% (equation image ± SD) of the assimilated nitrogen consumed by male grizzly bears, 38 ± 20% by female grizzly bears, and 23 ± 7% by male and female black bears came from animal matter. https://wildlife.onlinelibrary.wiley.com/doi/abs/10.1002/jwmg.483?casa_token=JGU9JINWtTEAAAAA%3AB5Bo0tlJAgNTc-8aWnTdizFMHbsQAoc7rCyTzJFalCs2m5rdtKIBjKnkIT7cCXDd1pEljrCTHc3imQ https://wildlife.onlinelibrary.wiley.com/doi/abs/10.1002/jwm... Diet varies a lot by region. Figure 7 here: <https://www.researchgate.net/profile/Bruce-Mclellan/publication/237973810_Implications_of_a_high-energy_and_low-protein_diet_on_the_body_composition_fitness_and_competitive_abilities_of_black_Ursus_americanus_and_grizzly_Ursus_arctos_bears/links/56d0865908ae85c82348721d/Implications-of-a-high-energy-and-low-protein-diet-on-the-body-composition-fitness-and-competitive-abilities-of-black-Ursus-americanus-and-grizzly-Ursus-arctos-bears.pdf https://www.researchgate.net/profile/Bruce-Mclellan/publicat...> Shows that for female grizzlies without salmon in their diets, % meat seems to vary from around 0% to 60% based on population.
  - pfdietz 5y ago
    Assimilated nitrogen != calories. Fish are rich in protein; plants have a large share of digestible carbohydrates.

The vast majority is plant matter. It wastes a lot of energy to chase prey. Plants don't move much. Last I read it was on the order of 80% plants, with a lot of insects being most of the meat.

samizdis 5y ago

You may be right that the majority is plant matter, but in salmon season bears gather at salmon runs and waste little energy in snatching fish as they leap up the cascades. See [1]. (Although individual bears do compete for the best fishing spots, they are in a "fish in a barrel" situation when they get one. They don't have to chase anything, just grab and chew.) [1] https://explore.org/livecams/brown-bears/brown-bear-salmon-cam-brooks-falls https://explore.org/livecams/brown-bears/brown-bear-salmon-c... Edit to add: Here's an article [2] from 2018, How many salmon will a bear eat? Excerpt: Adult male bears on Kodiak ate the most salmon on average, consuming an incredible 6,146 pounds (2,788 kg) per bear per year! Adult females ate 3,007 pounds (1,364 kg). Salmon consumption varied among subadult bears, independent juvenile bears between 2.5 and 5.5 years old. Subadult females ate 1,248 pounds (566 kg) while subadult males ate 1,305 pounds (592 kg) of salmon per bear per year. [2] https://medium.com/@exploreorg/how-many-salmon-will-a-bear-eat-94d3d212f178 https://medium.com/@exploreorg/how-many-salmon-will-a-bear-e...

nradov 5y ago
The bears catch so many salmon on some rivers that they eat only the most nutritious parts and leave the rest of the carcass for scavengers.
- AlbertCory 5y ago
  Correct. See my post and [1]. I saw this behavior myself. It's not just standing and snatching fish out of the stream, though. Most bears have to chase the fish and try to catch them, often failing. [1] https://photos.app.goo.gl/mXMHAjDyQNDjFqjw8 https://photos.app.goo.gl/mXMHAjDyQNDjFqjw8
mtnGoat 5y ago
costs a lot to feed bears. this years salmon price is estimated at $14-20\lb. if we take the average, a bear eats more then $100k a year worth of salmon.
- AlbertCory 5y ago
  It's cheaper when you buy it near the source.
  - mtnGoat 5y ago
    True, and probably cheaper buying in that kind of bulk. Still an impressive amount of fish.
monocasa 5y ago
Also, breaking down plant matter is very energy intensive. Salmon is very close to what animals need, sort of by definition.

Turing_Machine 5y ago

While that is true for inland brown/grizzly bears, the coastal brown bears under discussion in this article eat huge quantities of spawning salmon during the summer and early fall. They get much larger and much fatter than the inland bears as a result.

celrod 5y ago
More than 20% for many inland grizzly bears, e.g. Yellowstone: Approximately 45 ± 22% (equation image ± SD) of the assimilated nitrogen consumed by male grizzly bears, 38 ± 20% by female grizzly bears, and 23 ± 7% by male and female black bears came from animal matter. https://wildlife.onlinelibrary.wiley.com/doi/abs/10.1002/jwmg.483?casa_token=JGU9JINWtTEAAAAA%3AB5Bo0tlJAgNTc-8aWnTdizFMHbsQAoc7rCyTzJFalCs2m5rdtKIBjKnkIT7cCXDd1pEljrCTHc3imQ https://wildlife.onlinelibrary.wiley.com/doi/abs/10.1002/jwm... Diet varies a lot by region. Figure 7 here: <https://www.researchgate.net/profile/Bruce-Mclellan/publication/237973810_Implications_of_a_high-energy_and_low-protein_diet_on_the_body_composition_fitness_and_competitive_abilities_of_black_Ursus_americanus_and_grizzly_Ursus_arctos_bears/links/56d0865908ae85c82348721d/Implications-of-a-high-energy-and-low-protein-diet-on-the-body-composition-fitness-and-competitive-abilities-of-black-Ursus-americanus-and-grizzly-Ursus-arctos-bears.pdf https://www.researchgate.net/profile/Bruce-Mclellan/publicat...> Shows that for female grizzlies without salmon in their diets, % meat seems to vary from around 0% to 60% based on population.
- pfdietz 5y ago
  Assimilated nitrogen != calories. Fish are rich in protein; plants have a large share of digestible carbohydrates.