Global Bird Species in Serious Decline

Sidamo larkResearchers have known about the speckled brown Sidamo lark for only 40 years. Always a rare sight, the elusive bird may soon vanish from the prairie grasses of Ethiopia forever.

Its habitat already restricted to less than 100 square kilometers, the lark is rapidly losing territory as local residents, the Borana ethnic group, convert grassland into heavily grazed pasture. Unless the Borana are allowed to resume their nomadic ways, within the next few years the Sidamo lark will likely become the first known bird species to vanish from mainland Africa, researchers say.

"We estimate there are fewer than 250 adult individuals left," said Claire Spottiswoode, a research fellow at the University of Cambridge. "In the absence of urgent conservation action on the ground, it is only a matter of time before it goes extinct; no other species on the continent seems to face quite such an imminent fate."

The Sidamo lark is among the most endangered birds included on the Red List of Threatened Species, which the International Union for the Conservation of Nature (IUCN) updated last month for global bird species and for European amphibians and reptiles.

The IUCN Red List, considered the authority on the status of the world's plant and animal species, now includes 1,227 bird species (12 percent of known birds) as threatened with extinction - 192 of them critically endangered.

Habitat loss, climate change, and the spread of invasive species are the main threats to avian biodiversity, the conservation organization said.

"In global terms, things continue to get worse," said Leon Bennun, director of science and policy for BirdLife International, which conducted the updated research. "But there are some real conservation success stories this year to give us hope and point the way forward."

IUCN upgraded three bird species from "critically endangered" to "endangered" due to successful habitat protection strategies. Among the advances, a 2007 survey found that the bright blue Lear's macaw of Brazil had expanded to a population size of 750, after being reduced to only 70 wild individuals in the late 1980s.

The Red List was also updated with a continent-wide assessment of Europe's amphibians and reptiles.

Amphibians are in particular danger. Habitat loss is threatening nearly all of the continent's species, with nearly 60 percent in decline and 23 percent classified as threatened. Pollution, including climate change, and invasive species are leading causes of biodiversity loss as well. 

The Karpathos frog, for example, is found only on the Greek island that shares its name. The amphibian occupies less than 10 square kilometers near the island's northern mountains. Despite its remote habitat, the frog's breeding waters are at risk of being significantly altered by excessive water loss and climate change.

Europe's reptiles likewise suffer from habitat loss and fragmentation. Pollution, overharvesting, and intentional killings are additional threats. About 21 percent of the continent's reptiles are considered threatened, and 42 percent are in decline.

"Natural habitats across Europe are being squeezed by growing human populations, agricultural intensification, urban sprawl, and pollution," said Helen Temple, co-author of the IUCN study, in a statement. "That is not good news for either amphibians or reptiles."

The downward trend has become prevalent across all plant and animal classes. Of the 44,838 species that IUCN included in its 2008 Red List, about 38 percent were designated as "threatened" and 7 percent as "critically endangered." Biologists generally agree that unless a global effort to conserve the world's imperiled species gets under way - by addressing climate change, containing the spread of invasive species, and reversing damaging land use changes - mass extinctions may wipe out as many as half the planet's species by the end of this century.

Ben Block is a staff writer with the Worldwatch Institute. He can be reached at bblock@worldwatch.org.

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