Walruses in Alaska are coming off the ice floes and onto the shore, in the tens of thousands.
The sea ice they normally rest on has melted. On the shores of Alaska, the walruses are now packed shoulder to shoulder, for more than a kilometre.
This is very unusual behaviour for walruses, although it has happened twice before -- last year and in 2007 -- when the Arctic sea ice was at record low levels.
The U.S. government is now doing some research to figure out if walruses should be put on the endangered species list.
In the meantime, they are changing the flight patterns of planes that fly overhead, so they don't spook the walruses. And they're watching the animals to make sure they don't crush each other in their crowded condition.
Normally at this time the females would be resting on sea ice and diving down to the sea bottom for clams and worms. But since there's not enough sea ice, they're forced to stay on shore.
Scientists don't know how long the walruses will be on the shore, but they say there should be enough food for all of them.
Photo credit: The image of these Alaskan walruses was taken by an employee at NOAA, the US-based National Oceanic and Atmospheric Administration.