Keepers at Pocatello Zoo, Idaho, were worried when they noticed Shooter, a four-year-old elk, acting strangely at his water trough.

Baffled, they watched as the animal - who is so massive some keepers are afraid to even enter his enclosure - tried to dip his hooves into his drinking trough, before attempting to dunk his whole head in the water.

But they were amazed as 10ft tall Shooter lifted his head from the trough clutching a tiny marmot - a kind of large squirrel - between his jaws.

Great photos for this article...