Jack Dykinga / Ponderosa pine (Pinus ponderosa) growing in Grand Staircase-Escalante National Monument, Utah, October 2014.

Jack Dykinga / Ponderosa pine (Pinus ponderosa) against a star filled sky with a brilliant Milky Way. Zion National Park, Utah, USA, September.

Alex Mustard / A split level view of a bull California sealion (Zalophus californianus) swimming beneath Los Islotes sealion colony. La Paz, Mexico. Sea of Cortez, East Pacific Ocean.

Yva Momatiuk & John Eastcott / Pacific Walrus (Odobenus rosmarus divergens) bull portrait on coastal rocks in haul-out cove, summer, Round Island, Bering Sea, Bristol Bay, Alaska

Tui De Roy / Campbell Albatross (Thalassarche impavida) portrait of two month old chick awaiting parent's feeding, Bull Rock, North Cape Colony, Campbell Island, New Zealand

Tui De Roy / Campbell Albatross (Thalassarche impavida) coming in to land, Bull Rock Cape Colony, Campbell Island, New Zealand

Tui De Roy / Campbell Albatross (Thalassarche impavida) pair at Bull Rock, North Cape Colony, Campbell Island, New Zealand

Tui De Roy / Campbell Albatross (Thalassarche impavida) coming in to land, Bull Rock, North Cape Colony, Campbell Island, New Zealand

Jack Dykinga / Ponderosa pine (Pinus ponderosa) infront of petrified sand dunes with ephemeral waterfall after autumn rains, Grand Staircase-Escalante National Monument, Utah, USA. October.

Jack Dykinga / Moran Point with Ponderosa pine (Pinus ponderosa) and rock spires, Grand Canyon National Park, Arizona, USA.

Philippe Clement / Replica of prehistoric rock paintings of the Chauvet Cave. Replica in Nationalparkzentrum Falkenstein, Bavarian Forest NP, Germany. Showing extinct Cave lion and Auroch bull (Bos primigenius) Editoria...

Floris van Breugel / Arrowleaf balsamroot (Balsamorhiza sagittata) flowers in bloom on slope with Ponderosa pines (Pinus ponderosa) Eastern Washington, USA, May 2014.

Chris Mattison / Ponderosa Pine (Pinus ponderosa) branch silhoutted against sunset, Sierra Nevada, California, USA, May.

Floris van Breugel / Ponderosa pines (Pinus ponderosa) in winter snow, near Sisters, Oregon, USA. December 2009.

Todd Mintz / Sea kelp (Nereocystis luetkeana) with Rock Fish, Port Hardy, British Columbia, Canada.

Bryan and Cherry Alexander / Moulting Svalbard bull Reindeer (Rangifer tarandus) grazing on rich vegetation below Alkhornet bird cliff. Spitsbergen, Svalbard, Norway, June 2006.

Charlie Summers / American Bison (Bison bison) bull scratching on a prairie rock, Custer State Park of South Dakota, USA

Pete Oxford / South American sealion (Otaria flavescens) bull sitting on rock, Kidney Island, Falkland Islands

Pete Oxford / South American sealion (Otaria flavescens) bull on rock with two females in the sea, Kidney Island, Falkland Islands

Steven Kazlowski / South American sealion (Otaria flavescens) bull sunning himself on a rock. Falkland Islands, South Atlantic Ocean

Pete Oxford / Stellars sealion young bull on rock {Eumetopias jubata} Aleutian Is, Alaska, USA

Yva Momatiuk & John Eastcott / Pacific Walrus (Odobenus rosmarus divergens) males with large tusks resting on coastal rocks, summer, Round Island, Bering Sea, Bristol Bay, Alaska

Yva Momatiuk & John Eastcott / Pacific Walrus (Odobenus rosmarus divergens) bull portrait on coastal rocks in haul-out cove, summer, Round Island, Bering Sea, Bristol Bay, Alaska

Yva Momatiuk & John Eastcott / Pacific Walrus (Odobenus rosmarus divergens) bull portrait on coastal rocks in haul-out cove, summer, Round Island, Bering Sea, Bristol Bay, Alaska

Yva Momatiuk & John Eastcott / Pacific Walrus (Odobenus rosmarus divergens) bull portrait on coastal rocks in haul-out cove, summer, Round Island, Bering Sea, Bristol Bay, Alaska

Yva Momatiuk & John Eastcott / Pacific Walrus (Odobenus rosmarus divergens) bull portrait on coastal rocks in haul-out cove, summer, Round Island, Bering Sea, Bristol Bay, Alaska

Yva Momatiuk & John Eastcott / Pacific Walrus (Odobenus rosmarus divergens) bulls interacting in crowded haul-out cove, summer, Round Island, Bering Sea, Bristol Bay, Alaska

Tui De Roy / Grey-headed Albatross (Thalassarche chrysostoma) returning parent greeting chick, Bull Rock, North Cape Colony, Campbell Island, New Zealand

Tui De Roy / Grey-headed Albatross (Thalassarche chrysostoma) chick begging for food from parent, Bull Rock, North Cape Colony, Campbell Island, New Zealand

Tui De Roy / Campbell Albatross (Thalassarche impavida), Bull Rock, North Cape Colony, Campbell Island, New Zealand

Tui De Roy / Campbell Albatross (Thalassarche impavida) portrait of two month old chick awaiting parent's feeding, Bull Rock, North Cape Colony, Campbell Island, New Zealand

Tui De Roy / Campbell Albatross (Thalassarche impavida) pair courtship dance, Bull Rock, North Cape Colony, only breeding area, estimated at 26,000 pairs, Campbell Island, New Zealand

Tui De Roy / Campbell Albatross (Thalassarche impavida) pair courtship dance, Bull Rock, North Cape Colony, only breeding area, estimated at 26,000 pairs, Campbell Island, New Zealand

Tui De Roy / Campbell Albatross (Thalassarche impavida) adults and chick at bull rock, North Cape Colony, only breeding area, estimated at 26,000 pairs, Campbell Island, New Zealand

Tui De Roy / Campbell Albatross (Thalassarche impavida) two month old chick awaiting parents feeding, Bull Rock, North Cape Colony, Campbell Island, New Zealand

Tui De Roy / Campbell Albatross (Thalassarche impavida) bull rock north cape colony, only breeding area estimated at 26,000 pairs, Campbell Island, New Zealand

Tui De Roy / Campbell Albatross (Thalassarche impavida) courtship dance sequence, Bull Rock North Cape Colony, Campbell Island, New Zealand

Tui De Roy / Campbell Albatross (Thalassarche impavida) courtship dance sequence, Bull Rock North Cape Colony, Campbell Island, New Zealand

Tui De Roy / Campbell Albatross (Thalassarche impavida) courtship dance sequence, Bull Rock North Cape Colony, Campbell Island, New Zealand

Tui De Roy / Campbell Albatross (Thalassarche impavida) two month old chick awaiting parents feeding, Bull Rock, North Cape Colony, Campbell Island, New Zealand

Tui De Roy / Campbell Albatross (Thalassarche impavida), Bull Rock, North Cape Colony, Campbell Island, New Zealand

John Cancalosi / Fossil brachiopods in rock {Strophomena spp} Bull Fork Formation, Indiana Ordovician

Kirkendall-Spring / Gerimiah Holy Bull, a member of the Sioux Rosebud Tribe of Native Americans, standing on rock wearing traditional dress, South Dakota, USA. June, 2022.

Doug Gimesy / Bull kelp (Durvillaea antarctica) exposed by the tide, Auckland Island, Auckland Island, Sub-Antarctic Islands, New Zealand, Southern Ocean, January.

Doug Gimesy / Eastern rockhopper penguin (Eudyptes chrysocome filholi) splashing into rockpool after leaping off rocky ledge, surrounded by Bull kelp (Durvillaea antarctica), Auckland Island, Auckland Island, Sub-A...

Doug Gimesy / Eastern rockhopper penguin (Eudyptes chrysocome filholi) mid-fall after jumping off rocky ledge to get to sea, surrounded by Bull kelp (Durvillaea antarctica), Auckland Island, Auckland Island, Sub-An...

Jack Dykinga / Ponderosa pine (Pinus ponderosa) forest, trees covered in hoar frost after winter storm. Bryce Canyon National Park, Utah, USA. February 1999.

David Hall / Rose anemone (Urticina piscivora), Painted anemone (Urticina crassicornis), Brooding anemones (Epiactis spp.), Plumose anemones (Metridium spp.), Bull kelp (Nereocystis luetkeana) and Stalked kelp (Pt...

David Hall / Black rockfish (Sebastes melanops) amongst Bull kelp (Nereocystis luetkeana); Hunt Rock, Queen Charlotte Strait, British Columbia, Canada. September.

David Hall / Black rockfish (Sebastes melanops) amongst Bull kelp (Nereocystis luetkeana); Hunt Rock, Queen Charlotte Strait, British Columbia, Canada. September.

David Hall / Mixed aggregation of rockfishes (Sebastes spp.) with Bull kelp (Nereocystis luetkeana), Hunt Rock, Queen Charlotte Strait, British Columbia, Canada.

David Hall / Schooling rockfishes (Sebastes spp.) with Bull kelp (Nereocystis luetkeana). Different species of rockfish often swim together in mixed schools, as here. Hunt Rock, Queen Charlotte Strait, British Col...

David Hall / Lion's mane jellyfish (Cyanea capillata) and Bull kelp (Nereocystis luetkeana) Hunt Rock, Queen Charlotte Strait, British Columbia. October.