“Climate Change Causes Storks in Spain to Rely on Garbage Diet”
This article discusses how climate change is causing European white storks to migrate less and instead find food at landfills in Madrid, Spain. These birds have become a symbol of luck and fertility in the city, but the garbage they feed on has caused the spread of pollutants into reservoirs and drinking water sources, as well as tension among humans due to their large nests. A European Union directive aims to reduce organic waste in landfills, which would reduce food available to the storks.
COLMENAR VIEJO, Spain (AP) — The storks soar and swoop in formation, circling over a garbage dump in the foothills of the Sierra de Guadarrama north of Madrid. Then a garbage truck pulls up and pours out its contents. One after the other they dive to the ground: Breakfast is here.
Storks of Europe used to fly south to Africa’s Sahel to spend the winter, stopping in Spain en route. But with higher temperatures brought on by human-caused climate change and plentiful food available in open landfills, most adult storks no longer make the long and arduous journey.
At the Colmenar Viejo landfill in Madrid, about 100 trucks a day dump household waste into a crater, which is then covered with sand by excavators. Hundreds of white storks have built nests up to two meters long on the roofs and in the bell tower of the nearby church. There are even nests on street lamps.
“This is a stork paradise because they have grass, pastures and then the landfill, so they have everything here,” said Alejandro López García, who studies the stork population in Madrid for his PhD at the Complutense University of Madrid.
According to a census in autumn 2020, researchers found 36,217 of the approximately 450,000 white storks in Europe in Spain. This makes it the most popular host country for this breed on the continent, alongside Poland. In the Madrid area alone, López García said his team recently counted 2,300 breeding pairs of birds, compared to just 200 recorded in 1984.
Higher temperatures are likely to continue, meaning more birds will be attracted to Madrid during the winter. Other species such as swallows no longer migrate further south to Africa. Researchers at Zurich Technical University have predicted that the average temperature in the Spanish capital’s coldest month will rise by 3.1 degrees Celsius by 2050.
The storks feed on insects, rodents and worms that they pull out of the garbage, thus supplementing their diet. But for this traditional symbol of luck and fertility, danger lurks among the growing piles of garbage.
“With better weather and higher temperatures, storks have more free insects and worms to feed on,” said Blas Molina, an ornithologist working for Spanish bird conservation organization SEO/Birdlife. “But every year, chicks and adults die from ingesting plastic or rubber, which they mistake for worms,” Molina added. “In many cases, their legs become tangled in plastic cords that cut off their blood supply, and they eventually die from it.”
The negative effects of the storks’ garbage feeding also reach the human population. Storks from across Europe will still make a short hop south in winter, but feeding at rubbish dumps can spill potentially toxic chemicals into reservoirs and drinking water sources they stop at along the way. “Any pollutants that you have here, or potentially toxic compounds, end up in these waters,” explained López García.
According to López García, there is also a clear trend for storks to build their nests away from traditional wetlands and into adjacent urban areas. These large birds are very loyal to their nesting sites and return to them year after year, concentrating their populations in landfill sites across Spain.
Humans and storks are increasingly living side by side in a sometimes awkward compromise. White storks can have a wingspan of up to 7 feet and weigh up to 10 pounds, so they need plenty of space to nest. In Rivas-Vaciamadrid, a commuter town southeast of Madrid, the birds have taken up residence at the metro station and the local church.
Councilor Carmen Rebollo called the storks “our neighbors” and said the birds were universally popular. However, managing their living space has been a challenge. “The only difficulty we can have with them is that at some point they can build overly heavy nests or damage a roof, but at this moment we’re trying to reduce, adjust or move the nests,” she said .
López García acknowledged that the rapid spread of storks has created tensions around Madrid in recent decades. “Areas with two nests in the village church, parish or town hall are fine, but if the concentration is 30 nests then that can disturb people,” he said.
Now that the storks have changed their migratory and breeding patterns to adapt to the plentiful garbage heaps on offer, a new threat looms. In 2020, Spain transposed into national law a European Union directive aimed at preventing all organic waste from ending up in landfill. This is precisely the waste that fills up with mice, insects and worms, which the storks eat in droves.
“That means the food they’re eating right now would no longer exist,” López García said, proposing keeping a stork-eating area at the dumps. “What we’re proposing is that there is a smooth transition that doesn’t happen overnight, or a closure of landfills.”
However, according to López García, the ultimate benefit of reducing global warming methane from cutting organic matter in landfills outweighs the benefits of the food source the storks can find here. “In the medium to long term, feeding from landfills is negative for them,” he said.
___
Follow AP’s climate and environmental reporting at https://apnews.com/hub/climate-and-environment
___
The Associated Press’s climate and environmental reporting is supported by several private foundations. Learn more about AP’s climate initiative here. The AP is solely responsible for all content.
Jennifer O’mahony and David Montero Sierra, The Associated Press
Don’t miss interesting posts on Famousbio
