CHENNAI, April 12: A 50-hectare area of Government-owned land in the Adyar Creek region is to be declared a bird sanctuary. The Creek is in the heart of Chennai, and offers a unique bio-diversity system of distinct habitats and micro-habitats, which attracts large flocks of birds in winter. The Madras Nature Society says over 8,500 birds have been sighted here each year, but over the last two years, there has been a decline in both numbers and species.