Carol Walker / Cowboy riding in snow throwing a loop, Flitner Ranch, Shell, Wyoming, USA

Carol Walker / Silhouette of cowboy trotting, swinging a loop at sunset, Flitner Ranch, Shell, Wyoming, USA Model released

Carol Walker / Cowboy riding in snow throwing a loop, Flitner Ranch, Shell, Wyoming, USA Model released

Kirkendall-Spring / View overlooking the badlands from Scenic Loop Drive, Theodore Roosevelt NP, North Dakota, USA

Solvin Zankl / Seed heads of European groovebur (Agrimonia eupatoria) Europe. Burs on the seeds enable hook-and-loop connections between the seed and animal fur or peoples clothes, thus ensuring seed dispersal.

Tim MacMillan / John Downer Pr / Multiple exposure of flying Paradise tree snake showing how it forms a loop for maximum thrust as it lauches itself into air (Resolution restriction - image digitised from film, 'Weird Nature' tv seri...

Jiri Lochman / Little long-tailed dunnart (Sminthopsis dolichura) Useless Loop, Shark Bay, Western Australia - October.

Duncan Murrell / Batak man making a loop from rattan for a tree-climbing aid in Cleopatras Needle Critical Habitat, Palawan, the Philippines. September 2016.

Duncan Murrell / Batak man preparing a rattan loop for a tree-climbing aid in Cleopatras Needle Critical Habitat, Palawan, the Philippines. September 2016.

Kirkendall-Spring / Forest along the Spruce Loop in the Hoh Rain Forest, Olympic National Park, Washington, USA, April.

Kirkendall-Spring / Trees growing from the root ball of a fallen tree, Spruce Loop in the Hoh Rain Forest, Olympic National Park, Washington, USA, April.

Kirkendall-Spring / Row of trees which have grown from a fallen nurse log, Spruce Loop, Hoh Rain Forest of Olympic National Park, Washington, USA, April.