Spotted Imperial-Pigeon

The spotted imperial pigeon, also known as the grey-necked imperial pigeon, is a species of bird in the family Columbidae. This species is endemic to the Philippines. Its natural habitat is tropical moist lowland forests and tropical moist montane forest but seasonally migrates to limestone shorelines in large flocks of up to 50 individuals, for still unknown and not-well studied reasons but the prevailing theories is that it feeds on the calcium deposits.. Among the imperial pigeons of the Philippines, this species is the most threatened - assessed as a Vulnerable species with population estimates of 1,200 to 3,200 mature individuals and still believed to be on the decline due to habitat loss, hunting and capture for the illegal wildlife trade.

Source: Wikipedia