Thanjavur: Taking census of birds is no easy task. “You have to be an early bird to take census of birds which start their activities at the crack of dawn,” says Dr K. Arivoli, district forest officer (DFO) of Tiruvarur district.
Census of birds are taken every year in February at the Vaduvur birds sanctuary. Volunteers and members from Salim Ali Centre for Ornithology and Natiural History (Sacon) do the census every year. As they are well versed with birds and their activities, they rise early in the morning and catch them without making any noise and stand by lake side by counting which involves various methods like individual counting, which is used when birds are less in number and could be counted individually, grouping when counting is done in a single species flock, selective counting when the flock is with mixed species, proportions when the flock is with too many species, timing when a group of birds pass a point when flying and digital photograph which can be used for counting birds. “But then this has to be done from 6 am to 9 am; birds don't like noise or human interference and prefer loneliness,” Arivoli said.
Birds migrate for prey and nesting. Increase in temperature and decrease in resources make them to move to places where they can nest, prey and breed also. “We release fishlings into the lake so that birds may prey upon them. Fruit trees have also been planted so that they may prey upon fruits.” said the DFO.
Bird count helps in finding out a particular sanctuary continue to remain the sought after sanctuary for the avi fauna. Change in their population indicates shifts in pollution levels, climate change, habitat loss, migration timing and more. “Arrival of birds to Vaduvur birds sanctuary is increasing year after year and we have now recorded 138 species of birds that frequent this sanctuary. They include migratory birds from Siberia, Sri Lanka, Bangladesh among others; pintai duck and common teals are some of the migratory birds,” added Arivoli.
