Loic Poidevin / Rough-legged buzzard (Buteo lagopus) in flight. Varanger, Norway. May.

Charlie Summers / Stars draw traces above Naabi Hill acacia trees, Serengeti National Park, Tanzania

Charlie Summers / Maasai Giraffe (Giraffa camelopardalis) feeding on Acacia tree, Serengeti, Tanzania

Nick Garbutt / Acacia sp. at night, with a herd of Plains Zebra (Equus quagga) beneath. Near Ndutu, Nogorongoro Conservation Area, Serengeti National Park, Tanzania.

Rolf Nussbaumer / Green Jay (Cyanocorax yncas) perched on blooming Huisache tree (Acacia farnesiana) Dinero, Lake Corpus Christi, South Texas, USA

Wild Wonders of Europe / Radisics / White mimosa tree (Acacia dealbata) flowers, Madeira, March 2009

Stephen Belcher / Camelthorn Acacia (Acacia erioloba) dead tree with dunes in background, Namib-Naukluft National Park, Namibia

Jouan & Rius / Shadow of a Camelthorn tree (Acacia erioloba) in Tsauchab valley, Namib Naukluft NP, Namib desert, Namibia

Mary McDonald / Two African Elephants {Loxodonta africana} silhouetted beside Acacia tree, Samburu NP, Kenya.

Jack Dykinga / Ray of light falling on a lone Acacia tree in the Masai Mara, Kenya

Jack Dykinga / Rays of light illuminating the sky as the sun sets behind an Acacia tree, Masai Mara, Kenya

Jack Dykinga / Sun setting behind an Acacia tree with vultures roosting in its canopy. Masai Mara, Kenya

Anup Shah / Sun setting over Serengeti NP with Acacia tree, Tanzania

Richard Du Toit / Giraffes (Giraffa camelopardalis) at dawn by Acacia tree, Moremi Wildlife Reserve, Botswana

Anup Shah / Spotted hyaena {Crocuta crocuta} at dusk walking to Acacia tree. Maasai Mara, Kenya.

Anup Shah / Gerenuk standing grazing on Acacia tree {Litocranius walleri} Buffalo Springs, Kenya

Gerry Ellis / Whistling Thorn (Acacia drepanolobium) tree over savannah, Masai Mara National Reserve, Kenya

Mitsuaki Iwago / Masai Giraffe (Giraffa tippelskirchi) feeding on Whistling Thorn (Acacia drepanolobium) acacia tree, Serengeti National Park, Tanzania

Mitsuaki Iwago / African Elephant (Loxodonta africana) herd staying cool in the shade of an Acacia tree, Botswana

Gerry Ellis / Whistling Thorn (Acacia drepanolobium) and moon, Amboseli National Park, Kenya

Mitsuaki Iwago / Whistling Thorn (Acacia drepanolobium) tree on savannah at sunset, Serengeti

Shin Yoshino / Whistling Thorn (Acacia drepanolobium) trees, Masai Mara National Reserve, Kenya

Anup Shah / Patas monkey male sitting under Acacia tree {Erythrocebus patas} Kenya

Mark Moffett / Ant (Pseudomyrmex sp) group drink nectar from Whistling Thorn (Acacia drepanolobium) acacia tree and protect the tree from leaf eating enemies ensuring mutual survival, Costa Rica

Mark Moffett / Ant (Pseudomyrmex sp) gathers carrot-like growths from Whistling Thorn (Acacia drepanolobium) acacia tree for delivery to larva in nest, in return for baby food, ant protects Acacia, Costa Rica

Anup Shah / Female patas monkey {Erythrocebus patas} feeding on acacia ants, Kenya.

TJ Rich / Cheetah cub in acacia tree {Acinonyx jubatus} Masai Mara, Kenya

TJ Rich / Cheetah cub in acacia tree {Acinonyx jubatus} Masai Mara, Kenya

Anup Shah / Masai Mara landscape with giraffes and Acacia trees, Kenya, East Africa

Christophe Courteau / Acacia Rat (Thallomys paedulcus) in an acacia tree, Okvango Delta, Botswana

Charlie Summers / Plains zebra (Equus quagga) dead colt hung in Acacia tree by a Leopard (Panthera pardus). The Leopard was resting at the base of the tree. Serengeti National Park, Tanzania

Charlie Summers / Maasai Giraffe (Giraffa camelopardalis tippelskirchi) feeding on Acacia tree, Serengeti, Tanzania

Sebastian Kennerknecht / Dromedary (Camelus dromedarius) camel browsing on Acacia (Acacia sp) tree, reducing food for native herbivores, Hawf Protected Area, Yemen

Konrad Wothe / Grey-headed Social-Weaver (Pseudonigrita arnaudi) nests in Acacia (Acacia sp) tree, Ruaha National Park, Tanzania

Mary McDonald / Silhouette of Acacia tree at sunrise, Masai Mara Game Reserve, Kenya, East Africa

Sergey Gorshkov / African scops owl (Otus senegalensis) perched on Acacia tree at night, Okavango delta, Botswana, April

Charlie Summers / Cape Golden Cobra (Naja nivea) foraging for potential prey in the cracks and crevices of an Acacia tree, Kgalagadi TB Park of South Africa, May

David Welling / Clay-colored Sparrow (Spizella pallida) perched in flowering Huisache tree (Acacia farnesiana) Rio Grande Valley, Texas, USA

Guy Edwardes / Secretary Bird (Sagittarius serpentarius) perched in acacia tree, Ngorongoro Conservation Area, Tanzania, Africa, February

Nick Garbutt / Acacia tree at dawn. Ngorongoro Conservation Area / Serengeti National Park, Tanzania. March 2010. (digitally stitched image)

Jouan & Rius / Mulga tree (Acacia aneura) on eroded plateau, Kennedy range National Park, Western Australia. August 2009

Jouan & Rius / Wattle tree (Acacia sp) in Kimberley, Western Australia. August 2009

Rolf Nussbaumer / Pyrrhuloxia (Cardinalis sinuatus) female perched on flowering Huisache tree (Acacia farnesiana) Dinero, Lake Corpus Christi, South Texas, USA

Rolf Nussbaumer / Pyrrhuloxia (Cardinalis sinuatus) female perched on flowering Huisache tree (Acacia farnesiana) Dinero, Lake Corpus Christi, South Texas, USA

Rolf Nussbaumer / Pyrrhuloxia (Cardinalis sinuatus) male perched on flowering Huisache tree (Acacia farnesiana) Dinero, Lake Corpus Christi, South Texas, USA

Rolf Nussbaumer / Pyrrhuloxia (Cardinalis sinuatus) male perched on blooming Huisache tree (Acacia farnesiana) Dinero, Lake Corpus Christi, South Texas, USA

Rolf Nussbaumer / Northern Mockingbird (Mimus polyglottos) perched on flowering Huisache tree (Acacia farnesiana) Dinero, Lake Corpus Christi, South Texas, USA

Rolf Nussbaumer / Northern Cardinal (Cardinalis cardinalis) male on flowering Huisache tree (Acacia farnesiana) Dinero, Lake Corpus Christi, South Texas, USA

Rolf Nussbaumer / Northern Cardinal (Cardinalis cardinalis) female on blooming Huisache tree (Acacia farnesiana) Dinero, Lake Corpus Christi, South Texas, USA

Rolf Nussbaumer / Green Jay (Cyanocorax yncas) perched on blooming Huisache tree (Acacia farnesiana) Dinero, Lake Corpus Christi, South Texas, USA

Hermann Brehm / Ashy starling (Cosomopsarsus unicolor) calling, perched in Acacia tree, Africa

Hermann Brehm / Superb starling (Lamprotornis superbus) perched in Acacia tree, Africa.

Hermann Brehm / Superb starling (Lamprotornis superbus) perched in Acacia tree, calling, Africa.

Rolf Nussbaumer / Audubon's Oriole (Icterus graduacauda) perched on flowering Huisache tree (Acacia farnesiana) Dinero, Lake Corpus Christi, South Texas, USA

Rolf Nussbaumer / American Goldfinches (Carduelis tristis) perched on flowering Huisache tree (Acacia farnesiana) Dinero, Lake Corpus Christi, South Texas, USA

Kristel Richard / Four wild Namib horses and a foal grazing in shade of acacia tree, Namib Nakluft National Park, Namib Desert, Namibia, October 2009

Chris Gomersall / Male Southern yellow billed hornbill (Tockus leucomelas) perched in acacia tree, Etosha National Park, Namibia, November

George Sanker / Male Reticulated giraffe (Giraffa camelopardalis reticulata) feeding on an Acacia tree at sunset, Samburu National Park, Kenya, January

Wild Wonders of Europe / della Ferrera / Secondary road on the Livanjsko Polje, with Black locust tree (Robinia pseudoacacia) blowing in the wind, Caprazlije area, Livasnsko Polje, Bosnia and Herzegovina, May 2009

Wild Wonders of Europe / della Ferrera / Black locust tree (Robinia pseudoacacia) blowing in strong Bora wind, Caprazlije area, Livasnsko Polje, Bosnia and Herzegovina, May 2009

Wild Wonders of Europe / Radisics / White mimosa tree (Acacia dealbata) flowers, Madeira, March 2009

Richard Du Toit / Reticulated Giraffe (Giraffa reticulata) female browsing on acacia tree, Ol Pejeta Conservancy, Kenya

Inaki Relanzon / Rothschild giraffe (Giraffa camelopardalis rothschildi) grazing on Acacia tree, Nakuru Lake National Park, Kenya, August, Critically endangered

Richard Du Toit / Acacia (Acacia sp) trees near dirt road, Chobe National Park, Botswana

Richard Du Toit / Acacia (Acacia sp) tree and termite mound with dust storm in background, Moremi Game Reserve, Botswana

Stephen Belcher / Camelthorn Acacia (Acacia erioloba) dead trees with dunes in background, Namib-Naukluft National Park, Namibia

Stephen Belcher / Camelthorn Acacia (Acacia erioloba) dead tree with dunes in background, Dead Vlei, Namib-Naukluft National Park, Namibia

Stephen Belcher / Camelthorn Acacia (Acacia erioloba) dead tree with dunes in background, Namib-Naukluft National Park, Namibia

Stephen Belcher / Camelthorn Acacia (Acacia erioloba) dead tree with dunes in background, Dead Vlei, Namib-Naukluft National Park, Namibia

Stephen Belcher / Camelthorn Acacia (Acacia erioloba) dead tree with dunes in background, Dead Vlei, Namib-Naukluft National Park, Namibia

Stephen Belcher / Camelthorn Acacia (Acacia erioloba) dead trees with dunes in background, Dead Vlei, Namib-Naukluft National Park, Namibia

Stephen Belcher / Camelthorn Acacia (Acacia erioloba) dead trees with dunes in background, Dead Vlei, Namib-Naukluft National Park, Namibia

Stephen Belcher / Camelthorn Acacia (Acacia erioloba) dead tree with dunes in background, Dead Vlei, Namib-Naukluft National Park, Namibia

Stephen Belcher / Camelthorn Acacia (Acacia erioloba) dead trees with dunes in background, Dead Vlei, Namib-Naukluft National Park, Namibia

Edwin Giesbers / Acacia tree (Acacia sp) with Wildebeest (Connochaetes taurinus) herd, Serengeti, Tanzania

Edwin Giesbers / Acacia tree (Acacia sp.) silhouetted, Tanzania

Jouan & Rius / Western Myall tree (Acacia papyrocarpa) growing in salt arid bush, South Australia, Australia

Jouan & Rius / Western Myall tree (Acacia papyrocarpa) growing in salt arid bush, South Australia

Jouan & Rius / Western myall tree (Acacia papyrocarpa) silhouetted at sunset in the salt arid bush, South Australia

Jouan & Rius / Wattle tree, Flinders Ranges National Park, South Australia, Australia

Jouan & Rius / Wattle tree, Flinders Ranges National Park, South Australia, Australia

Michele Westmorland / Acacia tree silhouetted at sunset, Duba Plains, Okavango Delta, Botswana

Michele Westmorland / Acacia tree silhouetted at sunset, Duba Plains, Okavango Delta, Botswana

Mary McDonald / Grey-headed Kingfisher {Halcyon leucocephala} flying from an Acacia tree in Samburu NR, Kenya.

Mary McDonald / African honey bee {Apis mellifera scutellata} nest in a yellow Fever tree {Acacia sp} Samburu NP, Kenya.

Michael & Patricia Fogden / Camelthorn Acacia (Acacia erioloba) trees among sand dunes at Sossus Vlei, Namib-Naukluft National Park, Namibia

Kevin Schafer / Black Rhinoceros (Diceros bicornis) browsing on acacia tree, Lewa Downs Reserve, Kenya

Ingo Arndt / Lappet-faced Vulture (Torgos tracheliotus) group sitting on top of acacia tree in savannah, Masai Mara National Reserve, Kenya

Ingo Arndt / Savannah with dead acacia tree, Masai Mara National Reserve, Kenya

Jack Dykinga / Common zebra (Equus burchellii) in grassland, with a band of sunlight on the horizon, and a lone acacia tree (Egyptica baratites). Masai Mara National Reserve, Kenya

Jack Dykinga / African elephant (Loxodonta africana) walking through long grasses, with a lone Acacia tree in the background, Masai Mara, Kenya

Jack Dykinga / Sun setting behind an Acacia tree with vultures roosting in its canopy. Masai Mara, Kenya

Jack Dykinga / African elephant (Loxodonta africana) walking through long grasses, with a lone Acacia tree in the background, Masai Mara, Kenya

Jack Dykinga / Sun setting behind an Acacia tree, Masai Mara, Kenya

Jack Dykinga / Sun setting behind an Acacia tree with vultures roosting in its canopy. Masai Mara, Kenya

Jack Dykinga / Two Common zebras (Equus quagga) in long grasses, with a lone Acacia tree in the background. Masai Mara, Kenya

Juan Manuel Borrero / Acacia tree in Drâa valley, Morocco December 2007