Steven Kazlowski,Steven Kazlowski / Polar bear (Ursus maritimus) juvenile spreading body weight over thin newly forming pack ice, trying not to break through, Beaufort Sea, off the 1002 area of the Arctic National Wildlife Refuge, North...

Steven Kazlowski,Steven Kazlowski / Polar bear (Ursus maritimus) juvenile rolling around on newly formed pack ice, Beaufort Sea, off the 1002 area of the Arctic National Wildlife Refuge, North Slope, Alaska

Steven Kazlowski,Steven Kazlowski / Polar bear (Ursus maritimus) portrait, female. Bernard Spit, 1002 area of the Arctic National Wildlife Refuge, North Slope, Alaska.

Steven Kazlowski,Steven Kazlowski / Polar bear (Ursus maritimus) curious adult head underwater, Beaufort Sea, off the 1002 area of the Arctic National Wildlife Refuge, North Slope, Alaska.

Steven Kazlowski,Steven Kazlowski / Polar bear (Ursus maritimus) young bear in freezing water during autumn freeze up, Bernard Spit, 1002 area of the Arctic National Wildlife Refuge, North Slope, Alaska, Beaufort Sea

Steven Kazlowski,Steven Kazlowski / Polar bear (Ursus maritimus) 4-5 year-old on pack ice, low angle shot, off the 1002 area of the Arctic National Wildlife Refuge, North Slope of the Brooks Range, Alaska, Beaufort Sea, autumn

David Woodfall / Bird hide, created by Birdwatch Ireland to study and monitor Little tern (Sterna albifrons) colony, indicator species of climate change. County Wicklow, Republic of Ireland. June.

David Woodfall / Two little tern (Sterna albifrons), one with sand eel landing at the nest amongst Black Oats growing on shell rich sands Machair , Indicator bird of climate change because of its dependence on sand ee...

David Woodfall / Little tern (Sterna albifrons ) with newly hatched chick, feeding sand eel-Hyperoplus spp.Indicator of climate change as Little terns are only able to feed in top layer of sea water , and as sea warms...

Andy Sands / Oxlips (Primula eliator) flowering in coppice woodland, a rare and important ancient woodland indicator species, Suffolk, England, UK, April

Andy Sands / Herb paris (Paris quadrifolia) Plant growing among other woodland plants indicator species of ancient woodland, Suffolk, England, UK, May

Andy Sands / Herb paris (Paris quadrifolia) Close up of flower from the side - indicator species of ancient woodland, Suffolk, England, UK, May, Focus Stacked