Hanne & Jens Eriksen / Nile rat (Arvicanthus niloticus) feeding on vegetation. Oman, March.

Nigel Cattlin / Papyrus sedge (Cyperus papyrus). Koh Kret, Nonthaburi Province, Thailand.

Chris Gomersall / White-throated or Smyrna kingfisher (Halcyon smyrnensis) perched in papyrus sedge (Cyperus papyrus), and photographed against the morning sun. Hula Valley, Israel. January

Michel Roggo / Papyrus (Cyperus papyrus) and other aquatic plants on the river bed of the Okavango river, Okavango Delta, Botswana, June 2014 . Photographed for The Freshwater Project

Michel Roggo / Papyrus (Cyperus papyrus) and other aquatic plants on the river bed of the Okavango river, Okavango Delta, Botswana, June 2014 . Photographed for The Freshwater Project

Michel Roggo / Papyrus (Cyperus papyrus) growing in a channel of the Okavango River, with flower stems, Okavango Delta, Botswana, June 2014. Photographed for The Freshwater Project

Bruno D'Amicis / Harvest of Nile grass (Cyperus papyrus) Fogera Plains, Lake Tana Biosphere Reserve, Ethiopia. December 2013.

Bruno D'Amicis / Nile grass (Cyperus papyrus) harvest for sale in Bahir Dar harbour. Lake Tana Biosphere Reserve, Ethiopia. December 2013.

Bruno D'Amicis / Traditional Nile grass boat with catch of fish. Bahir Dar, Lake Tana Biosphere Reserve, Ethiopia. December 2013.

Bruno D'Amicis / Traditional Nile grass boat with catch of fish. Bahir Dar, Lake Tana Biosphere Reserve, Ethiopia. December 2013.

Bruno D'Amicis / Nile grass (Cyperus papyrus) collectors carrying harvest at sunset, Jimba Wetlands, Lake Tana Biosphere Reserve, Ethiopia. December 2013.

Bruno D'Amicis / Man with fish caught in Blue Nile River, Lake Tana Biosphere Reserve, Ethiopia. December 2013.

Bruno D'Amicis / Man fishing on bank of Blue Nile river. Bahir Dar, Lake Tana Biosphere Reserve. Ethiopia. December 2013.

Bruno D'Amicis / Man fishing on bank of Blue Nile river. Bahir Dar, Lake Tana Biosphere Reserve. Ethiopia. December 2013.

Bruno D'Amicis / Fisherman on traditional Nile grass boat, Lake Tana Biosphere Reserve, Ethiopia. December 2013.

Bruno D'Amicis / Shoreline wetland of Tana Qirqos Island with Nile grass (Cyperus papyrus) Lake Tana Biosphere Reserve, Ethiopia.

Bruno D'Amicis / Weaver birds (Ploceus sp.) flock flying through Nile grass (Cyperus papyrus). Jimba wetland, Lake Tana Biosphere Reserve, Ethiopia

Bruno D'Amicis / Nile grass boats, carrying other boats and supplies. Lake Tana Biosphere Reserve, Ethiopia. December 2013.

Bruno D'Amicis / Family moving on Nile grass boats on Lake Tana Biosphere Reserve, Ethiopia. December 2013.

Suzi Eszterhas / Nile Crocodile {Crocodylus niloticus} mother watches over hatchlings in Mara River, Maasai Mara Reserve, Kenya *Digitally removed grass from foreground

David Tipling / Southern carmine bee-eater (Merops nubicoides) perched on Papyrus (Cyperus papyrus) stem, along edge of grassland fire, Okavango Delta, Botswana.

David Tipling / Two Southern carmine bee-eaters (Merops nubicoides) perched among Papyrus (Cyperus papyrus) with flames from grassland fire behind, Okavango Delta, Botswana.

Wim van den Heever / Nile crocodile (Crocodylus niloticus) lying on riverbank with mouth open, Chobe River, Botswana.

Loic Poidevin / Long-tailed cormorant (Phalacrocorax africanus) perched on Papyrus (Cyperus papyrus). Uganda. July.

Kristel Richard / Two female African elephants (Loxodonta africana) and calf feeding on papyrus (Cyperus papyrus) in delta. Okavango Delta, Botswana.

Roland Seitre / Four Nile rats / Kusu rats (Arvicanthis niloticus) huddling together, Sharjah Desert Park, UAE. Captive.

Roland Seitre / Nile rat / Kusu rat (Arvicanthis niloticus) portrait, Plzen Zoo. Captive.

Joel Sartore / Photo Ark / African grass rat (Arvicanthis niloticus niloticus) portrait, Plzen Zoo. Captive.

Joel Sartore / Photo Ark / African grass rat (Arvicanthis niloticus niloticus) portrait, Plzen Zoo. Captive.

Charlie Summers / African grass rat (Arvicanthis niloticus) foraging at the base of some aloe plants. Serengeti, Tanzania