Yashpal Rathore / Oriental darter (Anhinga melanogaster), roosting at sunset, Keoladeo / Bharatpur National Park UNESCO Natural World Heritage Site, India

Ann & Steve Toon / African darter (Anhinga rufa), Chobe river, Botswana, June

Roger Powell / Oriental darter (Anhinga melanogaster) perched in small eucalyptus tree & drying water-logged plumage. Fogg Dam, Northern Territory, Australia

Roger Powell / Oriental darter (Anhinga melanogaster) perched in small eucalyptus tree. Fogg Dam, Northern Territory, Australia

Wim van den Heever / African darter (Anhinga rufa) drying its wings on a branch after hunting in the Chobe river, Botswana.

David Pattyn / Darters (Anhinga melanogaster) and Little cormorants (Phalacrocorax niger) sitting on a dead tree in a lake, Ranthambore National Park, Rajasthan, India

David Pattyn / Darters (Anhinga melanogaster) and Little cormorants (Phalacrocorax niger) sitting on a dead tree in a lake, Ranthambore National Park, Rajasthan, India

David Pattyn / Darters (Anhinga melanogaster) and Little cormorants (Phalacrocorax niger) sitting on a dead tree in a lake, Ranthambore National Park, Rajasthan, India

Bruno D'Amicis / African Darter (Anhinga rufa) nesting colony, Tana Mtsili Island, Lake Tana Biosphere Reserve, Ethiopia.

Bruno D'Amicis / African Darter (Anhinga rufa) in flight. Lake Tana Biosphere Reserve, Ethiopia.

Andy Rouse / Indian darter (Anhinga melanogaster) warming up wings, silhouetted at sunrise, Ranthambhore, India.

Juergen Freund / Australasian Darter (Anhinga novaehollandiae) with fish, Yellow Water wetlands, Northern Territory, Australia.