Covid-19 face masks, a chocolate wrapper from 1994 and a 30-year-old polystyrene burger box – the nests of Amsterdam’s Eurasian coots chart changes to consumer society through plastic waste.
Usually, Eurasian coots (Fulica atra) build their waterside nests from scratch each year using natural, biodegradable materials like rushes, reeds and leaves. But in Amsterdam’s busy city centre, such materials are in short supply along the riverbanks. Instead, these coots rely on plastic litter to build their nests, says at the Naturalis Biodiversity Center in Leiden, the Netherlands.
“More and more birds worldwide are using artificial materials for their nests,” he says. “It’s a very big trend. Some birds just include one or two pieces of trash in their nests, but coots [use] hundreds. That makes them very interesting for us to study.” These plastic nests don’t break down, so they are being reused and built on each year, says Hiemstra. In this way, the nests preserve layers of historical litter.
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Hiemstra and his colleagues collected 15 coot nests across Amsterdam after the 2021 breeding season and separated out the plastic components from natural materials. They then used information from the litter, such as “best before” labels on perishable foods, to date the plastic.
All the nests contained plastic litter, but two featured a wide array of this waste. In one of them, the team found the wrapper of a plastic chocolate bar featuring an advert for the 1994 FIFA World Cup, as well as a McDonald’s McChicken burger box from around 1996 and a thick layer of face masks, presumably from the height of the covid-19 pandemic.
Re-using these plastic-rich nests rather than building afresh each year could save the birds time and energy during breeding season, but there are risks to using plastic materials in this way. Chicks could easily become tangled in the elastic straps of face masks, for example.
However, the coots’ willingness to nest with plastic may help explain their ability to survive in the city centre, says Hiemstra. “They are one of the only birds that truly adopted plastic as a nesting material,” he says. “While some say it is a very sad development, I also think it is a very creative development.”
Some of the nesting material collected for the study will be on display at the Museon-Omniversum in The Hague, the Netherlands, as part of its collection on the Anthropocene, a term used to describe humanity’s enduring impact on the natural world. Hiemstra calls his team’s findings “a documentation of the Anthropocene through the eyes of a bird”.
Ecology
