The status of Great Slaty Woodpecker (Mulleripicus pulverulentus), a species of bird which can be found in the Philippines, has been raised from "least concern" to "vulnerable," following the rapid decline in its population in the last 20 years, largely on the account of the forest denudation, the United Kingdom-based Birdlife International said Wednesday.

In raising the alarm, Birdlife cited the 2010 International Union for Conservation of Nature (IUCN) Red List of Threatened Species for birds, noting the significant drop in the number of Great Slaty Woodpecker arising from the loss of primary forest cover throughout much of its range.

“The number of Great Slaty Woodpecker may have declined 90 percent on historical levels, and a significant decline within the past couple of decades,” BirdLife said.

This species thrives in subtropical or tropical moist lowland forests and tropical mangrove forests.

A species is considered “least concern” when there is no immediate threat to its survival while “vulnerable” refers to the high risk of extinction in the medium-term.

The UK-based non-government organization that focuses on the conservation of biodiversity hinted that that the true rate of decline may even be greater than currently estimated, and "evidence of such declines may result in the species being uplisted in the future."

The vulnerability of Great Slaty Woodpecker is a bit worrisome as it has been recognized to be the largest species of woodpecker in the world on the back of the probable extinction of the Imperial Woodpecker and the possible extinction of Ivory-billed Woodpecker.

The bird is a member of the Picidae Family with a current population estimated at 26,000 to 550,000.