The salmon run has yet to begin, but the big bruisers are already vying for dominance in Alaska.。

One of the five webcams along Katmai National Park's Brooks River captured an early-season confrontation between two of the river's largest and most dominant bears on June 26.。

SEE ALSO:From puffins to brown bears: The 10 best wildlife livestreams of the summer。

Bear 747, spotted earlier this week in the river, was seen waiting for fish beneath the famous Brooks River falls on Tuesday. You can watch the confrontation in the video below:。

At the 40-second mark, another bear, numbered 856 by park biologists, enters the picture. Bear 856 seeks the prime fishing grounds beneath the waterfall where most fish collect, the very place where 747 is fishing.。

Matters escalate, and by the end of the clip (at about the 4:55 mark), 856 aggressively chases 747 from the river. 856 then returns alone, with the river to himself. 。

Both bears have a long history at the Brooks River, and 856's return is especially notable. For six years prior to 2017, Bear 856 was unquestionably the most dominant bear of the river -- with few bears even attempting to challenge him.。

In 2017, an injured Bear 856 had trouble putting on weight.Credit: nps/a. Ramos 。

But when Bear 856 returned during the summer of 2017, things were different.。

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"856 arrived last July with a slight limp, so he may have not been physically up to the task of challenging the other large males at the falls," Former Katmai ranger Mike Fitz, who has returned to the park to report on the bears for explore.org, said over email.。

But after seeing this late-June skirmish, Fitz acknowledges circumstances may have changed since last year.。

But after seeing this late-June skirmish, Fitz acknowledges circumstances may have changed since last year.。

Via Giphy。

"It appears to be a different story so far this summer," said Fitz. "856 might be the most dominant bear at Brooks Falls again." 。

Fitz has observed 856's dominance since 2011.。

"Out of hundreds of interactions I witnessed, one bear was consistently and clearly dominant over all others, 856," Fitz wrote on his naturalist blog last summer. "From 2011 to 2016, 856 wasn’t displaced once."。

When bears challenge each other for territory, one bear will often back off. Sometimes this is accomplished by a sort of "posturing," where they face off, like 747 and 856 at the 40-second mark. 856's act at the end of this clip, however, was an assertive show of dominance against another large bear. 。

But this season's dominance hierarchy is far from set. Last year's dominant male, which displaced an obviously enfeebled 856 from the river, has yet to show up. This bear, nicknamed "Chunk" by park rangers, is Bear 32. 。

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And when Bear 32 shows up, it appears he will meet a stronger, more assertive Bear 856. The bear cams will be watching, with some 18 hours of subarctic daylight.
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"The ebb and flow of the hierarchy is one of the most fascinating aspects of bear watching on the bear cam," said Fitz.。

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"The ebb and flow of the hierarchy is one of the most fascinating aspects of bear watching on the bear cam," said Fitz.。

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