Journalism of Courage
The offloading of Punes garbage at Urali Devachi might be a cause for much angst among the villagers,but the dump has turned a surprisingly welcome sight for ornithologists. A variety of migratory birds have,in recent years,been using it as a resting site owing to garbage dumps thermal heat that helps in conserving their energy for the next soaring flight.
A scientific study done by Punes ornithologists titled Metropolitan garbage dumps: possible winter migratory raptor monitoring stations in peninsular India was published in September in the Journal of Threatened Taxa. Interestingly,the peer-reviewed magazine,for the first time,also published the abstract in Marathi.
They decided to survey an open and large garbage dump at the outskirts of the city as an alternative visual winter raptor monitoring station. Pande says the survey was done in 2005-06 and it was found that a total of 355 raptors (steppe eagle,black eared kite and tawny eagle) migrated over a period of six observation days,with 250 adults and 105 juveniles. Ground temperatures at the garbage dump site and surrounding area,and the wing beat rate of migratory raptors before and after arrival in the early morning were measured.
The temperature of the garbage dump was significantly higher than the surrounding area,while the wing flapping rate was significantly lower over the garbage dump area. Mahabal,a former additional director with Zoological Survey of India,says it is possible that migrating raptors use garbage dump thermals in the early morning to save energy with soaring and gliding flight (versus flapping flight).
The researchers described the migration pattern of three species of raptors,their adult to juvenile ratios and wing beat count at the survey site and highlighted for the first time the importance of city garbage dumps as possible monitoring stations for the study of the dispersal of winter migrating raptors in peninsular India.
We have proposed visual autumn migratory raptor monitoring surveys at garbage dumps of cities to assess early morning winter migration as a tool for estimating their wintering populations in peninsular India. Such surveys will give us a larger picture of the magnitude of raptor dispersal and migration and their flyways in India, Sant says.
