It's been a rough year for Western Australia's iconic but endangered Carnaby's black cockatoos (Calyptorhynchus latirostris), which are endemic to the state and live nowhere else in the world. Their population has dropped 37 percent in the past year, from 12,954 roosting birds in 2010 to just 8,365 in 2011, according to the third Great Cocky Count, organized by BirdLife Australia and the Western Australia Department of Environment and Conservation (DEC), which mobilized more than 260 volunteers to survey 185 sites to help map the birds' habitats and monitor their population trends.

Although the birds have been protected for more than a decade under Australia's Environment Protection and Biodiversity Conservation Act of 1999, their numbers have declined because of habitat loss and competition from other species.

Carnaby's cockatoos (also known as short-billed black cockatoos or large black cockatoos) nest in the hollows of large trees. Many of these trees, typically 100 years old or more according to Australia's DEC, have been lost to logging or development, or to people trying to neaten up their properties. Meanwhile, loss of wild habitat means that other cockatoo species—galahs (Eolophus roseicapilla) and western long-billed corellas (Cacatua pastinator)—and feral European honey bees (Apis mellifera) are all crowded into the same region and are now competing with the endangered cockatoos for tree hollows. Meanwhile, loss of habitat—enhanced by drought and wildfires—have created what has been called a "food crisis for cockatoos," pushing starving birds into the suburbs around Perth in a quest for food. As if all of that weren't bad enough, the birds are also prized in the pet trade and illegal poaching remains a threat despite their protected status.

"Carnaby's cockatoo populations have halved in the past 45 years and…their range has retracted by about a third," Birdlife Australia program manager Cheryl Gole told Australian Geographic.

While Gole called the recent loss a "red flag," she cautioned that it is too early to start considering this drop to be a trend. The Great Cocky Count has produced reliable numbers only for 2010 and 2011. The first count, in 2006, relied on a different statistical model and is not held up as a comparison with the newer counts.

Nevertheless, the results have some conservation groups up in arms. "To lose more than a third of an endangered species in just one year is a devastating result and shows that current conservation measures are failing," said John McCarten, spokesperson for the Conservation Council of Western Australia, in a prepared statement.

Meanwhile, some people are angry that it took nearly a year for the government to release the 2011 count results and blame Western Australia Minister of the Environment Bill Marmion. "This is not the Great Cocky Count, this is the Great Cocky cover-up that Bill Marmion's been engaged in," shadow environment minister Sally Talbot, representing the opposition party, told PerthNow. "Eleven months after the 2011 Great Cocky Count he still didn't have the numbers, and now we can see why the minister was so anxious to not make them public. This is such a dramatic decline in the species that the government must be absolutely ashamed of its inaction."

For his part, Marmion told the media that "more research needs to be done to verify species numbers," and he defended the government's handling of the birds' plight, noting that it has invested more than $9.7 million in conservation funding and habitat preservation since 2008 to protect the Carnaby's cockatoo and two other threatened cockatoo species.

But the conservationists, it seems, have some reason to mistrust the government's commitment. According to the Sydney Morning Herald, it recently approved construction of new housing for the University of Western Australia that would be built over existing Carnaby's cockatoo habitat and is considering a highway expansion project that would further impact the cockatoo and more than 100 other bird species.

The DEC says people in Western Australia can help Carnaby's cockatoos by planting food plants or future nesting trees or erecting artificial habitats on their properties.

The 2012 Great Cocky Count will be held on April 15. BirdLife Australia is currently signing up volunteers, who may contact them at greatcockycount@birdlife.org.au

Photo by Ralph Green via Flickr. Used under Creative Commons license