Food wrappers, surgical masks, earbuds, and even windshield wipers... It is atop a true collection of debris that the coots in central Amsterdam lay their eggs. "Anything that falls into the water [of the canals] is likely to be used for the nests," explained Auke-Florian Hiemstra, a biologist at the Naturalis Biodiversity Center in Leiden, the Netherlands. "In this highly urbanized area where nature is almost absent, the only material the coots have at their disposal is waste."

Curious to know the contents of these "modern" nests - symptomatic of the "age of plastic" - the researcher and his colleagues dissected about 15 of them right after the 2021 breeding season. Inside, they found several hundred pieces of artificial debris, many of which were food wrappers, and a few twigs here and there – "but you really had to look for them," noted Hiemstra.

It was upon discovering a Mars candy wrapper nestled at the bottom of a nest that the biologists realized their work had taken on a whole new dimension, becoming a veritable archaeological dig through the remnants of several decades of waste. On the plastic wrapper of the chocolate bar were several elements proving it was about 30 years old: a 1991 copyright, a 1993 logo of the Fédération Internationale de Football Association (FIFA) and an advertisement for the 1994 FIFA World Cup, of which Mars was one of the official sponsors.

You have 74.55% of this article left to read. The rest is for subscribers only.