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Abstract: Spawning Yellowstone cutthroat trout (Oncorhynchus clarki) provide a source of highly
digestible energy for grizzly bears (Ursus arctos) that visit tributary streams to Yellowstone Lake
during the spring and early summer. During 1985–87, research documented grizzly bears fishing on
61% of the 124 tributary streams to the lake. Using track measurements, it was estimated that
a minimum of 44 grizzly bears fished those streams annually. During 1994, non-native lake trout
(Salvelinus namaycush) were discovered in Yellowstone Lake. Lake trout are efficient predators and
have the potential to reduce the native cutthroat population and negatively impact terrestrial predators
that use cutthroat trout as a food resource. In 1997, we began sampling a subset of streams (n ¼ 25)
from areas of Yellowstone Lake surveyed during the previous study to determine if changes in
spawner numbers or bear use had occurred. Comparisons of peak numbers and duration suggested
a considerable decline between study periods in streams in the West Thumb area of the lake. The
apparent decline may be due to predation by lake trout. Indices of bear use also declined on West
Thumb area streams. We used DNA from hair collected near spawning streams to estimate the
minimum number of bears visiting the vicinity of spawning streams. Seventy-four individual bears
were identified from 429 hair samples. The annual number of individuals detected ranged from 15 in
1997 to 33 in 2000. Seventy percent of genotypes identified were represented by more than 1 sample,
but only 31% of bears were documented more than 1 year of the study. Sixty-two (84%) bears were
only documented in 1 segment of the lake, whereas 12 (16%) were found in 2–3 lake segments.
Twenty-seven bears were identified from hair collected at multiple streams. One bear was identified on
6 streams in 2 segments of the lake and during 3 years of the study. We used encounter histories
derived from DNA and the Jolly-Seber procedure in Program MARK to produce annual estimates of
grizzly bears visiting streams. Approximately 68 grizzly bears visited the vicinity of cutthroat trout
spawning streams annually. Thus, approximately 14–21% of grizzly bears in the Greater Yellowstone
Ecosystem (GYE) may have used this threatened food resource annually. Yellowstone National Park
(YNP) is attempting to control the lake trout population in Yellowstone Lake; our results underscore
the importance of that effort to grizzly bears.
Jeezus, I agree with Bambistew, if you go in the woods, you might just die. Bears, bees, drown, fall, get an infection. Sick of someone always having to BLAME someone for everything. Oh, mighty is a loiya, now I get it, money to be made.
There are more bears than there has been in many years, there are more people using the forest and the national parks than ever before, doesn't take a @#$#%^#$% rocket scientist to figure out some of this is going to happen. Let it @#$%#$^#$% go.
I have always wondered if the lake trout was a convenient scapegoat to deflect criticism away from the let it burn policy.
Jeezus, I agree with Bambistew, if you go in the woods, you might just die. Bears, bees, drown, fall, get an infection. Sick of someone always having to BLAME someone for everything. Oh, mighty is a loiya, now I get it, money to be made.
There are more bears than there has been in many years, there are more people using the forest and the national parks than ever before, doesn't take a @#$#%^#$% rocket scientist to figure out some of this is going to happen. Let it @#$%#$^#$% go.
OK guys explain this one last year i hunted unit 50 Wy archery elk , One late morning i had a bull screaming from his bed , so i gave some serious cow calls i set my friend up about 70 yards to my right,, Within a few minutes i heard a twig snap behind me , HMMMMM im saying sat bull coming in the back trai,
Then i hear what sounds like a horse running Hmmm maybe the sat bull is runnin in i stand to see and i see this thing coming at me thru the sage Hmmm not an elk hmmm looks like a wolf NO its a grizz at this point we lock eyes , he sees me clear as day in one swift motion I reach for my bow Yes bow
arrow gets hung up on sage ,, the bear comes running broadside at about 10 yards or less .I start screaming, BEAR BEAR , he rund past me and kind of strange his tail is like tucked between his legs and he running looking over his shoulder , almost like a scared dog , i ran towards his direction to show him he best keep running ,,
Ok so explain what happened also note the wind was in the bears favor blowing right at him plus we just walked that path only minutes ago
My theory was he thought at first i was a cow elk , then after he smelt me he didnt care i was a human i guess i shocked him when i stood up But he was coming and fast at me ,
Louis