Alex Hyde / Peacock butterfly (Inachis io) feeding on Goat Willow catkins (Salix caprea), an important food source for pollinators in early spring. Peak District National Park, UK. April.

Alex Mustard / Emperor shrimp (Periclimenes imperator / Zenopontonia rex) hitchhiking on large t-bar nudibranch (Ceratosoma trilobatum) The shrimp gains food source and protection on the toxic seaslug. Bitung, North...

Ammonite / Honey bee (Apis mellifera) performing a waggle dance inside a hive to indicate the position and quality of a food source to other workers, France, July.

Ammonite / Close-up of Honey bee (Apis mellifera) performing a waggle dance on the edge of a swarm, indicating the position and quality of a food source, France, May.

Ammonite / Close-up of Honey bee (Apis mellifera) performing a waggle dance on the edge of a swarm, indicating the position and quality of a food source, France, May.

Ammonite / Close-up of Honey bees (Apis mellifera) performing a waggle dance on the edge of a swarm, indicating the position and quality of a food source, France, April.

Hanne & Jens Eriksen / Arabian waxbill {Estrilda rufibarba} flock on food source, Wadi Sardud, Tihama, Yemen

Kim Taylor / Honey bee {Apis mellifera} worker with full pollen sacs executing 'waggle dance' to indicate food source, UK

Ingo Arndt / Aerial photo of flowering European Lime trees (Tilia x europaea) which are an important food source for Honey bees (Apis mellifera), Germany. June.

Magnus Lundgren / Brown paper nautilus (Argonauta hians) surfing on a jellyfish, Balayan Bay, Luzon, Philippines. The nautilus uses its jellyfish host both as a food source, and as a defensive weapon. Photographed at n...

Magnus Lundgren / Brown paper nautilus (Argonauta hians) surfing on a jellyfish, Balayan Bay, Luzon, Philippines. The nautilus uses its jellyfish host both as a food source, and as a defensive weapon. Photographed at n...

Jen Guyton / White-backed vultures (Gyps africanus) pick at the drying and deflated skin of an elephant carcass (Loxodonta africana) while spotted hyenas (Crocuta crocuta) look on, Laikipia Plateau, Kenya. The hye...

Jen Guyton / Rüppell's griffon vultures (Gyps rueppelli) and white-backed vultures (Gyps africanus) feed on an elephant carcass (Loxodonta africana), Laikipia Plateau, Kenya. The elephant was killed by government...

Jen Guyton / White-backed vultures (Gyps africanus) pick at an elephant carcass (Loxodonta africana) while a spotted hyena (Crocuta crocuta) looks on, Laikipia Plateau, Kenya. The hyena is tinted a reddish-brown f...

Jen Guyton / Spotted hyenas (Crocuta crocuta), Rüppell's griffon vultures (Gyps rueppelli) and white-backed vultures (Gyps africanus) at the carcass of an elephant (Loxodonta africana), as the night and day shift...

Jen Guyton / Rüppell's griffon vulture (Gyps rueppelli) and spotted hyenas (Crocuta crocuta) pick at an elephant (Loxodonta africana) carcass at dawn, Laikipia Plateau, Kenya. This elephant was killed by governm...

Jen Guyton / A spotted hyena (Crocuta crocuta) chases a flock of white-backed vultures (Gyps africanus) away from an elephant carcass (Loxodonta africana), Laikipia Plateau, Kenya. The hyenas are tinted a reddish...

Jen Guyton / White-backed vultures (Gyps africanus) and spotted hyenas (Crocuta crocuta) pick at the drying and deflated skin of an elephant carcass (Loxodonta africana), Laikipia Plateau, Kenya. The hyenas are ti...

Matthew Maran / Goat willow (Salix caprea) felled by a Eurasian beaver (Castor fiber) with teeth marks The riverside tree will resprout with new shoots supplying a source of food for the beavers for years to come. De...

Matthew Maran / Goat willow (Salix caprea) felled by a Eurasian beaver (Castor fiber). The riverside tree will resprout with new shoots supplying a source of food for the beavers for years to come. Devon, England, UK...

Jen Guyton / Nile crocodile (Crocodylus niloticus) at water's edge with Great white pelican (Pelecanus onocrotalus) prey, and other crocodiles nearby trying to steal the prey. Msicadzi River, Gorongosa National Pa...

Jen Guyton / Nile crocodile (Crocodylus niloticus) at water's edge to feed on Great white pelican (Pelecanus onocrotalus) prey. With birds on the shore including pink-backed pelicans (Pelecanus rufescens), marabou...

Jen Guyton / Nile crocodile (Crocodylus niloticus) with Great white pelican (Pelecanus onocrotalus) prey. Other birds watch from the shore, including great egrets (Ardea alba), grey herons (Ardea cinerea) and hame...

Jen Guyton / Nile crocodile (Crocodylus niloticus) catching a Great white pelican (Pelecanus onocrotalus) prey, Msicadzi River, Gorongosa National Park, Mozambique. During the dry season many water sources dry up...

Jen Guyton / Nile crocodiles (Crocodylus niloticus) fighting over Great white pelican (Pelecanus onocrotalus) in the Msicadzi River, Gorongosa National Park, Mozambique. During the dry season many water sources...

Jen Guyton / Nile crocodile (Crocodylus niloticus) eating Great white pelican (Pelecanus onocrotalus). With birds on the shore including pink-backed pelicans (Pelecanus rufescens), marabou storks (Leptoptilos crum...

Jen Guyton / Nile crocodile (Crocodylus niloticus) underwater holding a Great white pelican (Pelecanus onocrotalus) prey. after a group of the birds dove into the river to hunt fish. Here, the crocodile slowly sw...

Jen Guyton / Nile crocodile (Crocodylus niloticus) with Great white pelican (Pelecanus onocrotalus) prey. Other pelicans flying or wings held up in alarm. Msicadzi River, Gorongosa National Park, Mozambique. Duri...

Jen Guyton / Nile crocodile (Crocodylus niloticus) with Great white pelican (Pelecanus onocrotalus) prey. Other pelicans with wings held up in alarm. Msicadzi River, Gorongosa National Park, Mozambique. During th...

Jen Guyton / Great white pelicans (Pelecanus onocrotalus) and pink-backed pelicans (Pelecanus rufescens) diving into the Musicadzi River, Gorongosa National Park, Mozambique. During the dry season many water sour...

Jen Guyton / Yellow-billed stork (Mycteria ibis) fishing in the Msicadzi River, Gorongosa National Park, Mozambique, while a Nile crocodile (Crocodylus niloticus) swims past. During the dry season many water sour...

Jen Guyton / Marabou stork (Leptoptilos crumenifer) drinking at sunset in the Msicadzi River, Gorongosa National Park, Mozambique. During the dry season many water sources dry up trapping fish in smaller areas. M...

Jen Guyton / Marabou storks (Leptoptilos crumenifer) and Yellow-billed storks (Mycteris ibis) sweeping the water for fish in the Msicadzi River, Gorongosa National Park, Mozambique. During the dry season many wa...

Jen Guyton / Great white pelican (Pelecanus onocrotalus) preening itself beside the Msicadzi River, Gorongosa National Park, Mozambique. During the dry season many water sources dry up trapping fish in smaller ar...

Jen Guyton / Great white pelicans (Pelecanus onocrotalus) preening beside the Msicadzi River, Gorongosa National Park, Mozambique. During the dry season many water sources dry up trapping fish in smaller areas....

Jen Guyton / Nile crocodile (Crocodylus niloticus) emerging from the Msicadzi River, to swallow a mouthful of fish as a yellow-billed stork (Mycteria ibis) scans for fish nearby. Msicadzi River, Gorongosa Nation...

Jen Guyton / Marabou stork (Leptoptilos crumenifer) watching Nile crocodile (Crocodylus niloticus) that has come up to swallow a mouthful of fish. Msicadzi River, Gorongosa National Park, Mozambique. The bird is...

Jen Guyton / Nile crocodile (Crocodylus niloticus) surfacing to eat tiny fish whilst a Marabou stork (Leptoptilos crumenifer) looks on, ready to steal a fish if the opportunity arose. Msicadzi River, Gorongosa Nat...

Jen Guyton / Nile crocodile (Crocodylus niloticus) surfacing to eat tiny fish whilst a Marabou stork (Leptoptilos crumenifer) looks on, ready to steal a fish if the opportunity arose. Msicadzi River, Gorongosa Nat...

Jen Guyton / Nile crocodile (Crocodylus niloticus) surfacing to eat tiny fish whilst a Marabou stork (Leptoptilos crumenifer) looks on, ready to steal a fish if the opportunity arose. Msicadzi River, Gorongosa Nat...

Jen Guyton / Yellow-billed stork (Mycteria ibis) hunting for fish near a Nile crocodile (Crocodylus niloticus) that has come up to swallow a mouthful of fish. Msicadzi River, Gorongosa National Park, Mozambique. D...

Jen Guyton / Birds squabbling over fish in the Msicadzi River. Pink-backed pelican (Pelecanus rufescens) biting at the head of another pelican with a pouch full of fish while a marabou stork (Leptoptilos crumenife...

Jen Guyton / Nile crocodile (Crocodylus niloticus) surfacing to eat tiny fish whilst a Marabou stork (Leptoptilos crumenifer) looks on, ready to steal a fish if the opportunity arose. Msicadzi River, Gorongosa Nat...

Jen Guyton / A Nile crocodile (Crocodylus niloticus) feeding on great white pelican (Pelecanus onocrotalus) in the Msicadzi River, Gorongosa National Park, Mozambique. During the dry season many water sources dry...

Doug Wechsler / Spectacled bear (Tremarctos ornatus) among Achupalla bromeliads a major food source; Antisanilla Reserve, Ecuador.

Doug Wechsler / Spectacled bear (Tremarctos ornatus) among Achupalla bromeliads a major food source; Antisanilla Reserve, Ecuador.

Doug Perrine / Phyllosoma larva of Spiny lobster (Palinurus sp.) riding a Purple jellyfish (Pelagia noctiluca), at night in surface waters of the deep ocean off Kailua Kona, Hawaii, USA. August. The larval crustacea...

Doug Perrine / Phyllosoma larva of Spiny lobster (Palinurus sp) riding a Purple jellyfish (Pelagia noctiluca), at night in surface waters of the deep ocean off Kailua Kona, Hawaii, August. The larval crustacean use...