Photo Slideshow

The Fight for Yasuni

Deep in the far reaches of the western Amazon basin, on the northern edge of Yasuni National Park, field biologists at the Tiputini Biodiversity Station are documenting record-setting species coexistence in a tropical forest environment that is just beginning to divulge its secrets. It is an ecosystem with little human presence, except for a growing band of researchers whose data have served as the scientific basis for policy recommendations aimed at stopping new oil activities and road construction in Yasuni.

  • Dense treetops under a blue sky.

    Treetops: Situated in close proximity to both the equator and the Andes Mountains, Yasuni National Park's unique geographical location marks the intersection of high plant diversity converging with the highest recorded diversity of three animal communities. The park is home to some 4000 plant species (including almost as many tree species in 1 hectare as found in all of North America), 200 species of mammals, and 600 bird species. Yasuni also contains more than 100,000 insect species per hectare—the highest level of insect diversity in the world for any taxonomic group. Ecuador's Yasuni National Park may be the most biodiverse forest on Earth. Credit: Bejat McCraken

  • Jaguar: The frequency of jaguar appearances in the Tiputini camera traps implies a greater density of the cat than has been reported for any other natural setting. A typical jaguar density might be one individual per 20 square kilometers, but in Tiputini, 16 were documented in 4 square kilometers over the 5-year-study period. This extreme local density is related to the elevated abundance of prey, a result of no recognizable hunting pressure. With further development slated for eastern Ecuador, jaguar movements are threatened by increasing habitat fragmentation. Credit: Tiputini Biodiversity Station (TBS)

  • Red Brocket Deer: High red brocket deer numbers, along with abundant herds of wild peccaries, are a ready source of prey for larger predatory cats such as jaguars and pumas. Credit: Tiputini Biodiversity Station (TBS)

  • Nocturnal Curassow: Never captured before on film, fruit-eating Nocturnal Curassows are an important seed-dispersal agent; their presence is an indicator of an intact ecosystem. Credit: Tiputini Biodiversity Station (TBS)

  • Spiny Rat: Although for many, a rat is a rat, this rodent is a typical unknown actor whose presence in the world's museums is represented by only a handful of specimens. This is the first time it has been photographed alive in the wild. Credit: Tiputini Biodiversity Station (TBS)

  • Common Potoo: Engineered for survival, the Common Potoo (with chick) is one of the most camouflaged birds in the world. This is but one of 600 species of birds found in Yasuni; many others are more secretive and difficult to document. Credit: Kelly Swing, TBS co-director

  • Salvin's Curassow: Elsewhere in the park near indigenous communities, terrestrial birds such as Salvin's Curassow are easily captured by hunters. They are usually eliminated with even moderate hunting pressure. Credit: Tiputini Biodiversity Station (TBS)

  • Tiger Tarantula: Between insects and other small invertebrates, such as spiders, this is where the real diversity lies—at least 100,000 species per hectare and minimally 1 million on the regional scale. Credit: Kelly Swing, TBS co-director

  • Giant Anteater: Although giant anteaters may be seen somewhat regularly in neotropical grasslands, they are a rare sight in rainforests. Credit: Tiputini Biodiversity Station (TBS)

  • Scientists say Yasuni's hill-studded landscape environment supports varying microclimate activities and a resulting diversity of species. Here an erosion gulley collects rainfall supporting aquatic life and other species, a distinct ecosystem from that found on the more humid ridge tops just a few meters upland. Credit: Bejat McCraken

  • Since 1980, oil exploration in the region has proliferated, with Yasuni presently under threat from new oil and gas projects whose access roads allow in a flood of indigenous settlers. Shacks like these now dot the landscape, leading to intensive agriculture, unsustainable hunting, and illegal logging. Credit: Bejat McCraken

  • As dusk settles in, the park's animals find sanctuary in the forest's protective darkness—a nighttime world captured in some 30,000 digital images taken by the station's camera traps. Scientists say that they want to better understand wildlife characteristics for clues on how a changing climate might affect plant and animal populations. Credit: Bejat McCraken

To most visitors, this piece of rainforest superficially resembles rainforest from anywhere in the world. Even the scientists studying the region say it is difficult to appreciate the extreme levels of biodiversity found in Yasuni because so many species remain hidden from view or undescribed by science. But so-called camera traps have begun to yield a treasure trove of images of large predator species cloaked in the darkness of night. Triggered by infrared beams planted around mineral deposits known as salt licks, the cameras have already captured five species of cats, with jaguars and ocelots most well represented, and two species of wild dogs, as well as abundant prey species such as tapir, two species of peccaries, and two species of deer. Other emblematic Amazonian fauna such as harpy eagles, anacondas, and black caimans are observed regularly, as are 10 species of primates. No hunting occurs in the area surrounding the camera trap program, which is sponsored by the Universidad San Francisco de Quito and a grant from the National Geographic Society, so these images show a forest that is likely similar to the one that existed as much as 10,000 years ago—before the ancestors of today's indigenous people migrated in the area.

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Read the accompanying News Focus in the 26 November issue of Science.
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