Anup Shah / Western lowland gorilla (Gorilla gorilla gorilla) sub-adult female 'Mosoko' aged 8 years crossing a river, Bai Hokou, Dzanga Sangha Special Dense Forest Reserve, Central African Republic

Ross Hoddinott / 2020VISION / Tarr Steps, medieval clapper bridge crossing the River Barle, Exmoor National Park, Somerset, UK. May 2012

Ingo Arndt / Timber Wolf (Canis lupus) crossing river, Minnesota

Yuri Shibnev / Wild Amur leopard (Panthera pardus orientalis) crossing a fallen tree over a river, Kedrovaya, Pad Reserve, Far East Russia 1987

Anup Shah / Western lowland gorilla (Gorilla gorilla gorilla) juvenile male 'Tembo' aged 4 years crossing a river in Bai Hokou, Dzanga Sangha Special Dense Forest Reserve, Central African Republic. December 2011.

Anup Shah / Western lowland gorilla (Gorilla gorilla gorilla) female 'Mopambi' carrying her infant 'Sopo' aged 18 months on her back crossing a river in Bai Hokou, Dzanga Sangha Special Dense Forest Reserve, Cent...

Anup Shah / Western lowland gorilla (Gorilla gorilla gorilla) dominant male silverback 'Makumba' aged 32 years drinking from a river while sub-adult female 'Mosoko' aged 8 years crosses bi-pedally, Bai Hokou, Dza...

Anup Shah / Western lowland gorilla (Gorilla gorilla gorilla) juvenile female 'Bokata' aged 6 years walking bi-pedally to cross a river, Bai Hokou, Dzanga Sangha Special Dense Forest Reserve, Central African Repu...

Anup Shah / Western lowland gorilla (Gorilla gorilla gorilla) juvenile female 'Bokata' aged 6 years walking bi-pedally to cross a river, Bai Hokou, Dzanga Sangha Special Dense Forest Reserve, Central African Repu...

Anup Shah / Western lowland gorilla (Gorilla gorilla gorilla) juvenile male 'Tembo' aged 4 years crossing a river bi-pedally while dominant male silverback 'Makumba' aged 32 years and juvenile male 'Mobangi' aged...

Anup Shah / Western lowland gorilla (Gorilla gorilla gorilla) dominant male silverback 'Makumba' aged 32 years walking bi-pedally across a river, Bai Hokou, Dzanga Sangha Special Dense Forest Reserve, Central Afr...

Anup Shah / Western lowland gorilla (Gorilla gorilla gorilla) sub-adult female 'Mosoko' aged 8 years walking bi-pedally across a river, Bai Hokou, Dzanga Sangha Special Dense Forest Reserve, Central African Repub...

Fiona Rogers / Western lowland gorilla (Gorilla gorilla gorilla) juvenile male 'Tembo' aged 4 years crossing a river bi-pedally, Bai Hokou, Dzanga Sangha Special Dense Forest Reserve, Central African Republic. Decem...

Will Watson / Two men crossing a cloud forest river in spate, Jama Coaque Reserve, Manabi Province, Ecuador, February 2012. No release available.

Anup Shah / Topi (Damaliscus lunatus jimela), Eastern White bearded Wildebeest (Connochaetes taurinus) and Common or Plains zebra (Equus quagga burchellii) mixed herd crossing the Mara River as part of annual mig...

Anup Shah / Eastern White bearded Wildebeest (Connochaetes taurinus) herd crossing the Mara River as part of annual migration, Masai Mara National Reserve, Kenya, August

Mark Hamblin / 2020VISION / European river otter (Lutra lutra) footprints crossing frozen Loch Lurgainn at dawn, with Sgorr Tuath and Sgorr Deas (Beinn an Eoin) behind, Coigach, Wester Ross, Scotland, UK, December 2010

Mark Hamblin / 2020VISION / European river otter (Lutra lutra) footprints crossing frozen Loch Lurgainn at dawn, with Sgorr Tuath & Sgorr Deas (Beinn an Eoin) behind, Coigach, Wester Ross, Scotland, UK, December 2010

Anup Shah / Aerial view of herd of Eastern White bearded wildebeest (Connochaetes taurinus albojubatus) crossing the Mara River watched by tourist vehicles, Masai Mara National Reserve, Kenya 2008

Grzegorz Lesniewski / Wisent / European Bison (Bison bonasus) crossing the Sun River. Bieszczady Mountains, the Carpathians, Bieszczady National Park, Poland, February.

Matthew Maran / Hikers crossing a thin footbridge over a river. The West Coast Trail, Pacific Rim National Park, Vancouver Island, Canada, September 2010, model released

Matthew Maran / A man sitting in the cable car of a chair bridge as it crosses a river. The West Coast Trail, Pacific Rim National Park, Vancouver Island, Canada, September 2010. Model released

Danny Green / 2020VISION / Red deer (Cervus elaphus) stag crossing a river, Bradgate Park, Leicestershire, England, UK, October

Anup Shah / Eastern White-bearded Wildebeest herd (Connochaetes taurinus) and Common / Plains zebra (Equus quagga burchellii) running away from the Mara River after crossing - wide angle perspective. Masai Mara N...

Anup Shah / Eastern White-bearded Wildebeest (Connochaetes taurinus) herd crossing the Mara River - wide angle perspective, Masai Mara National Reserve, Kenya. September 2009.

Anup Shah / Thomson's gazelles (Eudorcas thomsonii) following a herd of Wildebeest (Connochaetes taurinus) as they cross the Mara River, wide angle perspective, Masai Mara National Reserve, Kenya. September

Anup Shah / Eastern White-bearded Wildebeest (Connochaetes taurinus) herd crossing the Mara River - wide angle perspective Masai Mara National Reserve, Kenya. September

Anup Shah / Eastern White-bearded Wildebeest (Connochaetes taurinus) herd running after crossing Mara river, wide angle perspective. Masai Mara National Reserve, Kenya. September

Anup Shah / Eastern White-bearded Wildebeest (Connochaetes taurinus) herd crossing the Mara River, close up of legs - wide angle perspective. Masai Mara National Reserve, Kenya. September 2009.

Anup Shah / Masai giraffe (Giraffa camelopardalis tippelskirchi) crossing the Mara River - wide angle perspective, Masai Mara National Reserve, Kenya. August 2009.

Anup Shah / Eastern White-bearded Wildebeest herd (Connochaetes taurinus albojubatu) crossing the Mara River, Masai Mara National Reserve, Kenya. October

Anup Shah / Nile crocodile (Crocodylus niloticus) attacking a Thomson's gazelle (Eudorcas thomsonii) as it crosses the Mara River. Masai Mara National Reserve, Kenya, October 2009

Anup Shah / Nile crocodile (Crocodylus niloticus) attacking a Wildebeest (Connochaetes taurinus) as it crosses the Mara River. Masai Mara National Reserve, Kenya, October 2009

Anup Shah / Common or Plains zebra (Equus quagga burchellii)crossing the Mara River. Masai Mara National Reserve, Kenya, September 2009

Anup Shah / Eastern White-bearded Wildebeest herd (Connochaetes taurinus albojubatu) crossing the Mara River. Masai Mara National Reserve, Kenya, September 2009

Tim Laman / A young boy (model released) aged 9, crossing a fallen tree bridge with a hand rope that spans the river, at the research station in Gunung Palung NP. Borneo. July 2007

Tim Laman / A young boy (model released) aged 9, crossing the suspension bridge over the river at the research station in Gunung Palung NP, Borneo. July

Andy Rouse / Common wildebeest (Connochaetes taurinus) being held by crocodile during migration river crossing, Masai Mara, Kenya

Andy Rouse / Common wildebeest (Connochaetes taurinus) crossing river on migration, Masai Mara, Kenya

Andy Rouse / Common wildebeest (Connochaetes taurinus) gathering to cross river on migration, Masai Mara, Kenya

Andy Rouse / Common wildebeest (Connochaetes taurinus) crossing river on migration in rain, Masai Mara, Kenya, Africa

Andy Rouse / Common wildebeest (Connochaetes taurinus) crossing river on migration, Masai Mara, Kenya, Africa

Andy Rouse / Nile crocodile (Crocodylus niloticus) chasing Wildebeest (Connochaetes taurinus) during migration crossing, Masai Mara, Kenya, Africa

Ian McCarthy / Silhouette of mastiff dog crossing a bridge with Himalayas in the background, Upper Dolpo, Nepal

Ingo Arndt / Caribou (Rangifer tarandus) herd crossing a Kongakut River during summer migration, Arctic National Wildlife Refuge, Alaska

Ingo Arndt / Caribou (Rangifer tarandus) pair crossing a river during summer migration, Arctic National Wildlife Refuge, Alaska

Ingo Arndt / Caribou (Rangifer tarandus) bull crossing a river during summer migration, Arctic National Wildlife Refuge, Alaska

Ingo Arndt / Caribou (Rangifer tarandus) mother and calf crossing a river during summer migration, Arctic National Wildlife Refuge, Alaska

Wild Wonders of Europe / Schandy / People crossing a river on horses in the Arkhyz valley, the western part of the Teberdinsky Biosphere reserve, Caucasus, Russia, July 2008 (Model released)

Andy Rouse / African elephant (Loxodonta africana) breeding herd crossing river at sunset, South Luangwa, Zambia (non-ex)

Andy Rouse / African elephant (Loxodonta africana) breeding herd crossing river, Samburu GR, Kenya **Not available for world retail 2011 calendars**

Inaki Relanzon / Crossing river with a Land Rover, Landmannalaugar mountains, central Iceland. July 2008

Tony Heald / Pigtail Macaques (Macaca nemestrina) crossing purpose-built "primate wires" connecting isolated patches of forest, Kinabatangan River, Sukau, Sabah, Borneo, September 2008

Tony Heald / Danum River flowing through lowland dipterocarp rainforest with shadow of people on walkway crossing river, Danum Valley, Sabah, Borneo, September 2008

Anup Shah / Wildebeest {Connochaetes taurinus} running up river bank after crossing river on migration, Masai Mara GR, Kenya

Anup Shah / Herd of Wildebeest {Connochaetes taurinus} crossing river on migration, East Africa

Anup Shah / Wildebeest {Connochaetes taurinus} emerging from crossing the Mara river on migration, Masai Mara GR, Kenya. Wildebeest migrate annually a marathon distance of 1,000 miles!

Anup Shah / Wildebeest {Connochaetes taurinus} crossing the Mara river on migration, Masai Mara, Kenya

Suzi Eszterhas / Blue Wildebeest (Connochaetes taurinus) leaping into the Mara River during migration, Masai Mara National Reserve, Kenya

Suzi Eszterhas / Blue Wildebeest (Connochaetes taurinus) crossing the Mara River during migration, Masai Mara National Reserve, Kenya

Suzi Eszterhas / Blue Wildebeest (Connochaetes taurinus) crossing the Mara River during migration, Masai Mara National Reserve, Kenya

Suzi Eszterhas / Blue Wildebeest (Connochaetes taurinus) leaping into the Mara River during migration, Masai Mara National Reserve, Kenya

Anup Shah / Common zebra (Equus quagga) crossing river Masai Mara reserve, Kenya

Anup Shah / Wildebeest herd {Connochaetes taurinus} climbing bank after crossing river, Masai mara Reserve, Kenya

Anup Shah / Wildebeest herd {Connochaetes taurinus} climbing bank after crossing river, Maasai mara Reserve, Kenya

Anup Shah / Common zebra crossing river (Equus quagga) Masai Mara reserve, Kenya

Anup Shah / Common zebra (Equus quagga) crossing river Masai Mara reserve, Kenya

Karl Ammann / African elephants crossing river {Loxodonta africana} with Giraffes in forest behind. Kenya

Anup Shah / Herd of Wildebeest crossing river, Masai Mara GR, Kenya

Winfried Wisniewski / Blue Wildebeest (Connochaetes taurinus) migrating herd crossing river, Africa

Mark Raycroft / Elk (Cervus elaphus) bull crossing a river

Yva Momatiuk & John Eastcott / Blue Wildebeest (Connochaetes taurinus) herd trying to cross Mara River, fleeing from hungry Crocodiles, Masai Mara National Reserve, Kenya

Yva Momatiuk & John Eastcott / Burchell's Zebra (Equus burchellii) herd Blue Wildebeest (Connochaetes taurinus) and Thomson's Gazelles (Eudorcas thomsonii) congregate near crossing, Mara River, Masai Mara National Reserve, Kenya

Gerry Ellis / Burchell's Zebra (Equus burchellii) and Blue Wildebeest (Connochaetes taurinus) crossing the Mara River, Masai Mara National Reserve, Kenya

Michio Hoshino / Caribou (Rangifer tarandus) herd, Arctic National Wildlife Refuge, Alaska

Michio Hoshino / Caribou (Rangifer tarandus) herd migrating in summer, Arctic National Wildlife Refuge, Alaska

Michio Hoshino / Caribou (Rangifer tarandus) stampeding herd crossing river, Arctic National Wildlife Refuge, Alaska

Mitsuaki Iwago / Blue Wildebeest (Connochaetes taurinus) herd with Burchell's Zebra (Equus burchellii) crossing river during migration, Serengeti

Mitsuaki Iwago / Blue Wildebeest (Connochaetes taurinus) herd with Burchell's Zebra (Equus burchellii) crossing river during migration, Serengeti

Michio Hoshino / Caribou (Rangifer tarandus) group crossing through river during migration, Alaska

Anup Shah / Common zebra and wildebeest migrating herds crossing Mara river where crocodiles wait, Masai Mara, Kenya

Peter Blackwell / Nile crocodile attacking Wildebeest crossing River Mara, Kenya, Africa

Jabruson / African elephants crossing river with riders. Democratic Republic of Congo, Garamba National Park.

Peter Blackwell / Wildebeest migrating across the Mara River, Kenya

TJ Rich / Nile crocodile attempting to take zebra during crossing of Mara river {Crocodylus niloticus} Masai Mara, Kenya

Anup Shah / Wildebeest herd crossing Mara river {Connochaetes taurinus} on migration, Masai Mara NR Kenya, East Africa

Anup Shah / Nile crocodile attacking Wildebeest crossing river during migration, Masai Mara, Kenya

Anup Shah / Wildebeest crossing Mara river on migration , Masai Mara, Kenya

Anup Shah / Wildebeest (Connochaetes taurinus) and Common zebra (Equus quagga) crossing Mara river during migration, Masai Mara NR, Kenya

George Sanker / Moose (Alces alces) mother and baby crossing Gros Ventre River in the Grand Tetons. Grand Teton National Park, Wyoming, October.

Gavin Hellier / Bridge crossing the Taedong river, Juche Tower (symbol of the Juche Idea, penned by Kim Il Sung) Pyongyang, North Korea, Democratic Peoples' Republic of Korea (DPRK) April 2012

Denis-Huot / African Elephant (Loxodonta africana), baby crossing the Ewaso Ngiro river. Samburu game reserve, Kenya.

Winfried Wisniewski / Blue Wildebeest (Connochaetes taurinus) herd crossing Mara River, Masai Mara, Kenya

Nick Garbutt / Bachelor herd of bull African Elephants (Loxononta africana) crossing the Luangwa River. South Luangwa National Park, Zambia. Digital composite.

Nick Garbutt / Bachelor herd of bull African Elephants (Loxononta africana) crossing the Luangwa River. South Luangwa National Park, Zambia. Digital composite.

Danny Green / Wolf (Canis lupus) crossing a river. Yellowstone, USA, February.