Huge numbers of Pacific walrus have been coming ashore in northwest Alaska.
An estimated 35,000 animals were pictured at the weekend hauling themselves on to land north of Point Lay, about 500km southwest of Barrow.
The gathering was photographed as part of an annual survey undertaken by the US National Oceanic and Atmospheric Administration.
Walrus will generally rest on floes of Arctic sea ice, but when that is not available will head to nearby beaches.
Andrea Medeiros, a spokeswoman for the US Fish and Wildlife Service, told the Associated Press wire agency that the animals' mass movement was first detected on 13 September, and that they have been moving on and off shore ever since.
Observers have reported seeing carcasses, which may be from dead animals killed in a stampede. The biggest of these tusked beasts can weigh in excess of two tonnes.
Scientists were heading to the area to perform necropsies to determine the exact cause of death, Andrea Medeiros added.