Read the following extract and answer the question given below
With the onset of winter the picturesque nalaban bird sancturary inside the chilika lake is agog with the presence of thousands of migratroy birds from faraway siberia itraq and central europe
The birds arrice at their iwngter abode inside the bord sancturary which is spreasd over 15.5 sq km to stay fr five months till monosoon sets in this year the migration of winter bords has begun tow weeks ahead due to disturbances nad sacricty of food in their navtive places
The bords have taken sheltr in artifical mounds inside the sancturary lake the second largest in the workd has increased over the year due to the conductive atomospher prevaling there
A survey conducted by the chilika wildlife division has revealed that the number of migratory birds arriving at the lake has increased to over two million
Many rare birds like the smew duck mallard nakta marbled tela and goliath heron have also been spotted last year
application of pesticides and chemical in the fields and loss of natural habitat affect bird mirgration birds and animals have a relation ship and their harmonius presence is benefical for the continuity of a santuary
According to you why are santuaries essential for birds and animals ?
