The Philippines has created a protected area to save a species of endangered wild duck, with just 5,000 of the birds remaining, government documents released on Monday said.The 27 hectare (67 acre) \"wetland critical habitat\" was set up for the Philippine duck, a species found only in the Philippines whose numbers have been falling due to hunting and habitat destruction, the documents said.The environment department order created the protected area in the largely-agricultural Cabusao district in the east of the country. \"Ensure that existing ecosystems in the critical habitat are preserved and are kept in a condition that will support the perpetual existence of the Philippine duck,\" the department order instructed local authorities.The Philippine duck, whose scientific name is \"Anas luzonica\", is rated as \"vulnerable\" by the conservation group BirdLife International, which estimated in 2005 that as few as 5,000 of them may be left.On its website, BirdLife said the main threats to the species were excessive hunting and the use of its habitats for drainage and aquaculture -- the farming of aquatic organisms -- and excessive use of pesticides in rice farms. The duck is described as having a blue-grey bill, a \"rusty cinnamon\" head and neck, and brown and grey feathers. It feeds on fish, shrimps, insects, rice and other plants.