Martin Camm / Carwardine / Illustration of magnetic fields and dolphins stranding (Wildlife Art Company).

Richard Du Toit / Aerial view of Hippopotamus (Hippopotamus amphibius) amongst vegetation in water, Okavango delta, Botswana

Richard Du Toit / Aerial view of herd of African buffalo (Syncerus caffer) on the move, Okavango delta, Botswana

Hiroya Minakuchi / Blue Whale (Balaenoptera musculus) breathing at surface, California

Hiroya Minakuchi / Blue Whale (Balaenoptera musculus) tail at beginning of dive, California

Richard Du Toit / African Elephant (Loxodonta africana) and Blue Wildebeest (Connochaetes taurinus) herds on savanna, Masai Mara, Kenya

Richard Du Toit / African Elephant (Loxodonta africana) herd at river, Chobe River, Botswana

Hiroya Minakuchi / Risso's Dolphin (Grampus griseus) pod, California

Hiroya Minakuchi / Gray Whale (Eschrichtius robustus) pregnant female surfacing and spouting, Channel Islands, California

Richard Du Toit / Burchell's Zebra (Equus burchellii) herd crossing pan during summer dry season, Makgadikgadi Salt Pans, Botswana

Richard Du Toit / Great White Pelican (Pelecanus onocrotalus) flock taking-off, Okavango Delta, Botswana

Richard Du Toit / Hippopotamus (Hippopotamus amphibius) pod resting, Okavango Delta, Botswana

Richard Du Toit / Cape Buffalo (Syncerus caffer) herd followed by Cattle Egret (Bubulcus ibis) flock, Okavango Delta, Botswana

Hiroya Minakuchi / Risso's Dolphin (Grampus griseus) calf and mother surfacing, fetal folds visible on calf, California

Hiroya Minakuchi / Blue Whale (Balaenoptera musculus) diving, California

Hiroya Minakuchi / Risso's Dolphin (Grampus griseus) pod, California

Richard Du Toit / African Elephant (Loxodonta africana) herd in swamp, Okavango Delta, Botswana

Scott Leslie / Burned industrial logging area, Nova Scotia, Canada

Scott Leslie / Burned industrial logging area, Nova Scotia, Canada

Scott Leslie / Burned industrial logging area, Nova Scotia, Canada

Scott Leslie / Burned industrial logging area, Nova Scotia, Canada

Mark Carwardine / Blue whale (Balaenoptera musculus) Baja California, Mexico, North Pacific Aerial