Bence Mate / African buffalo (Syncerus caffer) and Warthog (Phacochoerus africanus) at night with full moon, Mkuze, South Africa Third place in the Nature Portfolio category of the World Press Photo Awards 2017.

Ann & Steve Toon / RF - Warthog male (Phacochoerus africanus) drinking, Zimanga game reserve, KwaZulu-Natal, South Africa, June. (This image may be licensed either as rights managed or royalty free.)

Neil Aldridge / Warthog (Phacochoerus africanus) with a Yellow-billed oxpecker (Buphagus africanus) on its back, nuzzling its mother at a waterhole, Chief's Island, Okavango Delta, Botswana.

Neil Aldridge / Red-billed oxpeckers (Buphagus erythrorhynchus) adult and young on the back of Common warthog (Phacochoerus africanus) through grassland in summer Mapungubwe National Park, South Africa.

Sandesh Kadur / Pygmy Hog (Porcula salvania) foraging. Captive, member of a reintroduction project. Assam, eastern India.

Sandesh Kadur / Pygmy Hog (Porcula salvania) seen through undergrowth. Captive, member of a reintroduction project. Assam, eastern India.

Edwin Giesbers / Red river hog (Potamochoerus porcus) close up of head, captive

Bert Willaert / Hognosed Pit Viper (Porthidium nasutum) coiled. Ecuador, South America.

Bernard Castelein / Hog Deer (Cervus / Axis / Hyelaphus porcinus) crossing a stream. Kaziranga National Park, Assam, India, February.

Anup Shah / Male Hog deer {Axis porcinus} with Oxpecker bird Kaziranga NP, Assam, India

Cyril Ruoso / Eastern Chimpanzee (Pan troglodytes schweinfurthii) , Frodo the dominant male and hunter, eating a Red River Hog (Potamochoerus porcus) piglet with two females begging, Gombe National Park, Tanzania

Cyril Ruoso / Cape Warthog (Phacochoerus aethiopicus) tusks, hunting trophies that get checked in customs in regard to CITES and local law, France

Juergen & Christine Sohns / African Wild Dog (Lycaon pictus) group attacking Cape Warthog (Phacochoerus aethiopicus), Tswalu Game Reserve, South Africa

Suzi Eszterhas / Cape Warthog (Phacochoerus aethiopicus) parent and juvenile drinking at waterhole, Mashatu Game Reserve, Botswana

Gerry Ellis / Cape Warthog (Phacochoerus aethiopicus) portrait, Kenya

Konrad Wothe / Domestic Pig (Sus scrofa domesticus) on grassy lawn, Germany

ZSSD / Red River Hog (Potamochoerus porcus) pair standing face to face, a highly social bush pig, native to Africa

ZSSD / Red River Hog (Potamochoerus porcus) four babies, a highly social bush pig, native to Africa

ZSSD / Red River Hog (Potamochoerus porcus) baby and mother interacting, a highly social bush pig native to West Africa

Eric Baccega / Babirusa (Babyrousa babyrussa) female with baby. Captive, occurs in Sulawesi, Indonesia

Tony Heald / Warthog (Phacochoeros aethiopicus) covered in mud after wallowing, Kruger National Park South Africa.

Ernie Janes / Red river hog (Potamochoerus porcus) portrait, captive, occurs in Congo and Guinea.

Adrian Davies / Hognosed pit viper (Porthidium nasutum) Costa Rica

Adrian Davies / Hognosed pit viper (Porthidium nasutum) Costa Rica

Nick Garbutt / Humboldt's hog-nosed skunk (Conepatus humboldtii). Torres del Paine National Park, Patagonia, Chile. November.

Ann & Steve Toon / Warthog (Phacochoerus africanus) with Redbilled oxpecker (Buphagus erythrorhynchus), Zimanga game reserve, KwaZulu-Natal, South Africa.

Ann & Steve Toon / Warthog (Phacochoerus africanus) drinking, with redbilled oxpeckers (Buphagus erythrorhynchus), Zimanga game reserve, KwaZulu-Natal, South Africa.

Ann & Steve Toon / Warthog (Phacochoerus africanus) drinking, with redbilled oxpecker (Buphagus erythrorhynchus), Zimanga game reserve, KwaZulu-Natal, South Africa.

Ann & Steve Toon / Warthog (Phacochoerus africanus) sounder on the move, Zimanga game reserve, KwaZulu-Natal, South Africa.

Ann & Steve Toon / Redbilled oxpecker (Buphagus erythrorhynchus) searching for insects on Warthog (Phacochoerus africanus), Zimanga game reserve, KwaZulu-Natal, South Africa.

Yashpal Rathore / African elephant (Loxodonta africana) and Warthog (Phacochoerus africanus) waiting near waterhole. Savuti, Chobe National Park, Botswana.

Staffan Widstrand / Common Warthog (Phacochoerus africanus) portrait, Zimanga Private Nature Reserve, KwaZulu Natal, South Africa

Staffan Widstrand / Common Warthog (Phacochoerus africanus), with a Red-billed Oxpecker (Buphagus erythrorhynchus) eating its ticks and other parasites, Zimanga Private Nature Reserve, KwaZulu Natal, South Africa

Staffan Widstrand / Common Warthog (Phacochoerus africanus) close up of eye and 'warts' Zimanga Private Nature Reserve, KwaZulu Natal, South Africa

Staffan Widstrand / Common Warthog (Phacochoerus africanus), with an African / Cape Buffalo in the foreground, Zimanga Private Nature Reserve, KwaZulu Natal, South Africa

Staffan Widstrand / Common Warthog (Phacochoerus africanus) reflected in water hole, Zimanga Private Nature Reserve, KwaZulu Natal, South Africa

Staffan Widstrand / Common Warthog (Phacochoerus africanus), with a Red-billed Oxpecker (Buphagus erythrorhynchus) eating its ticks and other parasites, Zimanga Private Nature Reserve, KwaZulu Natal, South Africa

Staffan Widstrand / Common Warthog (Phacochoerus africanus) silhouetted, Zimanga Private Nature Reserve, KwaZulu Natal, South Africa

Daniel Heuclin / Babiroussa (Babyrousa babyrussa) covered in mud, Sulawesi, captive.

Daniel Heuclin / Babiroussa (Babyrousa babyrussa) standing in water, Sulawesi, captive.

Daniel Heuclin / Babiroussa (Babyrousa babyrussa) covered in mud, Sulawesi, captive.

Will Watson / Water Hog-louse or Water Slater (Asellus aquaticus) on sallow leaf, Herefordshire Plateau, England, December 2018. Captive.

Will Watson / Water Hog-louse or Water Slater (Asellus aquaticus) with exopod regrowing, sallow leaf, captive conditions, garden pond, Herefordshire Plateau, England, December 2018.

Melvin Grey / Hog-nosed pit viper (Porthidium nasutum) Atlantic Lowland Rainforest, Costa Rica.

Paul Hobson / Hognosed pitviper (Porthidium nasutum). Costa Rica.

Suzi Eszterhas / African elephant (Loxodonta africana) herd at waterhole during dry season with Springbok (Antidorcas marsupialis), Plains zebra (Equus quagga) and Warthog (Phacochoerus africanus). Etosha National Par...

Ann & Steve Toon / Warthogs (Phacochoerus africanus) Zimanga Private Game Reserve, KwaZulu-Natal, South Africa.

Ann & Steve Toon / Whitebacked vultures (Gyps africanus) threat display to Warthog (Phacochoerus africanus) Zimanga Private Game Reserve, KwaZulu-Natal, South Africa.