Changing Planet

Wildlife on Islands of the Rio Negro

Touring through the Amazon I had the unique opportunity to spend a day visiting the small seasonally flooded islands of the Rio Negro. This dynamic landscape plays a huge role regulating local biodiversity. Our tour guide first lands us for a short walk on one of the small islands in the Parque Nacional de Anavilhanas. Unlike the dry land Amazon forest, in the river basin the constant seasonal flooding creates a disturbed forest landscape.

A seasonally flooded island of the Rio Negro, Brazil
A seasonally flooded island of the Rio Negro, Brazil (Photo by James Russell)

The low water levels at the end of the current dry season show the islands at their most exposed, but soon many of the islands, including the one I am on, will be flooded, and all the animals, including ant eaters and jaguars, will become arboreal for the four wettest months of the year. As we round one of the corners on the track, we see an iguana already practicing for this, basking on a large tree fall.

An iguana basks on a log perhaps in anticipation of Rio Negro flooding
An iguana basks on a log perhaps in anticipation of Rio Negro flooding (Photo by James Russell)

Whereas the seasonal flooding presents challenges to the land fauna, the river fauna will surely be looking forward to it. Amazon river dolphins (Inia geoffrensis) and manatee (Trichechus inunguis) found throughout the basin will be able to forage on the land resources made available to them.

An Amazon river dolphin pops its head above the surface (Photo by James Russell)

One group of species won’t be disturbed too much by the change in river levels whatsoever. The birds of the Amazon are heard and seen all around us. As we visit a local community of indigenous people further up the river, where our tour guide was born in fact, we see many of the birds attracted to the disturbed landscape with introduced fruit and other trees around the village.

Some birds of the Amazon forest: blue and yellow macaw, Amazon parrots, yellow rumped cacique, hummingbird
Some birds of the Amazon forest: blue and yellow macaw, Amazon parrots, yellow rumped cacique, hummingbird (Photos by James Russell)

Read All Posts by James Russell

Conservation biologist Dr. James Russell works throughout the world on remote islands and other sites to provide conservation solutions by applying a combination of scientific methods. Follow James on National Geographic voices for regular updates on his own work or other exciting developments in island conservation.

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