By nature, bears are solitary creatures - but when there's a river full of fish ready to leap straight into your paws, they will make an exception.
These astonishing pictures show the annual feeding frenzy that follows salmon-spawning season in the Katmai national Park in Alaska.
'The salmon are returning to Alaska from the open ocean in their millions in order to spawn. For thousands of brown bears all along the coast and spawning rivers, this means the dinner bell is ringing loudly,' says photographer Michael Nolan.
Snack time: Tens of brown bears visit the river in Katmai National Park, Alaska, every year for the bumper salmon crop
Mine: This river salmon looks to have made an ill-timed leap as a brown bear opens his vast jaws to grab its meal
'And of course, there is a constant push and shove for the very best fishing spots as older, stronger, and larger bears vie for the best positions.'
Coastal brown bears, also known as Alaskan Grizzlies, are among the largest land predators. they weigh up to 1,500lb - or as much as nine men - and stand more than 8ft tall on their hind legs.
Mr Nolan, 48, from Tuscon, Arizona, said: 'The Brooks River is one of the best fishing spots in Alaska where salmon can be found.
'July is summer time in the northern hemisphere and the salmon are returning to Alaska from open ocean in order to spawn literally by the millions.
'For thousands of brown bears all along the coast and spawning rivers this means the dinner bell is ringing loudly.
'The bears wait patiently for the fish to come to this spot, as all fish must get past the falls to spawn, or die trying.'
Surf and turf war: Two bears square up to each other as they argue over the best fishing spot
Michael Nolan spent a week capturing the bears on film and witnessed this rare gathering of up to 25 adults
Catch of the day: The Brooks River in Alaska is one of the best fishing spots for bears
Mr Nolan spent a week capturing the bears on film and witnessed this rare gathering of up to 25 adults and juveniles jostling for food.
He said: 'Bears are usually quite anti-social and prefer to be alone, but when the fishing is this good they will tolerate close proximity with other bears.
'Of course there is a constant push and shove for the very best fishing spots as older, stronger, and larger bears vie for the best positions to fish.
'Smaller and younger bears are relegated downstream to catch fish as they can, and to scavenge fish that the bigger bears have caught and eaten the best parts of upstream, letting the remains float down river for young bears to scavenge.'
Feeding frenzy: This bear looks out over the Brooks River in Katmai National Park, Alaska
Putting on a show: Spectators from around the globe look on as tens of brown bears congregate at the Brooks River in Alaska to catch salmon
The bears employ a variety of strategies to feast on the salmon, including catching them in mid-air as they jump over the falls, wading in the shallow water and even stealing from other bears.
Some dive underwater to grab their food and some even try to swat the salmon out of the water.
Even though human proximity to bears is generally a bad idea, Mr Nolan said the feeding frenzy draws in spectators from all over the world.
He added: 'Bears and people have come to an understanding in this part of Alaska, and it is not unusal at all to be less than 10 meters distant from what would otherwise be a very potentially dangerous animal in the wild.'
Read more: If you go down to the woods... Spectators watch from just 10 metres away as 20 Brown Bears gather for annual salmon feast | Mail Online