18, Jul 2018
Prelims level : Environment Mains level :
Why in News?
Harrier birds, a migratory raptor species that regularly visits India are declining.
About the Species:
- Harrier is one of the several species of diurnal hawks sometimes placed in the Circinae sub-family.
- Harriers characteristically hunt by flying low over open ground, feeding on small mammals, reptiles, or birds.
- Every winter, several species of harrier birds travel thousands of kilometres to escape Central Asia for the grasslands of the subcontinent.
- At least five species of harriers were recorded in India over the years and India has one of the largest roosting sites in the world for Pallid Harriers and Montagu’s Harriers.
- Hen Harrier Day (6th August) aims to show those who continue to persecute hen harriers, and other raptor species, that it will not be tolerated.
IUCN Red list Category:
- Montagu’s Harrier – Least concern
- Pallid Harrier – Near Threatened
- Western marsh Harrier – Least concern
- Malagasy marsh Harrier – Endangered
- Pied Harrier – Least concern.
Reason for the Decline:
- The grave concern is the loss of grasslands, either to urbanisation or to agriculture.
- Excessive use of pesticides in farms around the roosting sites kills the grasshoppers, the primary prey of the harriers. This leads to decline in the count of the birds themselves as they are on the top of the food chain.
- Extensive agriculture due to Drip irrigation and solar farms are also the reason for declining of its habitat.
- General declining trend was observed in all the monitored sites, researchers noted the most dramatic changes at the Rollapadu Bustard Sanctuary in Andhra Pradesh. Another roost site near Bengaluru was lost as the habitat around it changed. Hessarghatta on the outskirts of Bengaluru, western marsh harriers declined leaving the area nearly deserted.