London, March 16 (IANS) The influence of junk food on behaviour is not limited to humans. Researchers have found that white storks have become so addicted to burgers and sandwiches from landfill sites that since the mid-1980s the number of these birds migrating from Europe to their traditional winter homes in Africa has declined.
The study revealed that white storks are now increasingly preferring to stay in Spain or Portugal all year round to feed on the readily available abundant and reliable junk food supply from the mass landfill sites.
The bird is among a growing number of migratory species that have changed their behaviour due to human influences and global environmental change, the researchers rued.
The study, published in the journal Movement Ecology, revealed that the continuous availability of junk food from the waste sites influenced the bird's nest use, daily travel distances, and foraging ranges.
"Portugal's stork population has grown 10 fold over the last 20 years. The country is now home to around 14,000 wintering birds, and numbers continue to grow, said lead researcher Aldina Franco from University of East Anglia in Britain.
The team tracked 48 birds using GPS tracking devices, which transmit their positions five times a day. Each tracker also collected accelerometer information with detailed data about the birds' behaviour.
The data allowed the team to track the storks' movement between nesting and feeding areas, detect long and short distance flights, and study their behaviour -- to see whether they were standing and preening, foraging for food, or tending their eggs.
