European storks ditch migration during the winter to feed on landfill sites. A study of white storks in Spain and Portugal has found that many remain there all year round.
And some are so addicted to junk food that they will make a 60-mile return trip to their nearest rubbish dump just to fill their bellies with the easy meals, according to The Christian Science Monitor.
But while the practice may stop the birds, which have black wings and red legs and beaks, from helping new parents, it seems to be to their benefit.
“The landfill sites enable year-round nest use, which is an entirely new behavior that has developed very recently. This strategy enables the resident birds to select the best nest sites and start breeding earlier,” University of East Anglia researcher Aldina Franco said in a statement.
Franco studied 48 white storks for up for a year. Each bird was caught on a landfill site and fitted with lightweight backpack containing a tracking device, before being released.
Information about each bird’s location was transmitted five times a day and used to build up a picture of its movements. The results showed the storks to be making frequent trips to dumps, and the closer they lived to a site, the more they visited it.
The landfill sites were particularly popular over the winter, when the worms, frogs, and voles normally eaten by the birds were in shorter supply, and when migration to the warmer climes of Africa would be the norm.
However, the strategy to ditch the annual migration may backfire in the long-term. Writing in the journal Movement Ecology, Franco said that under European Union rules, Portugal will be replacing its open-air rubbish dumps with covered sites.
“This will cause a problem for the storks, as they will have to find an alternative winter food supply. It may well impact their distribution, breeding location, chick fledgling success and migratory decisions,” she said.
White storks are occasionally spotted in Britain but the birds have not bred here for 600 years.
Earlier this year, European researchers in Germany using similar methods to track the birds found that storks which fed at landfill sites were more likely to survive the winter after ditching their migration. The birds are one of a number of species which have adapted their behavior to take advantage of humans’ lifestyle of environmental excess.
It is believed that while the trash may provide higher calorie food sources for the birds, it could have knock on ecological impacts, including the increased numbers of fish and insects they feed on - such as locusts. Without the birds picking off the insect’s numbers, it could potentially lead to more crop damage.