‘I hope people will open their eyes to urban nature’

According to biologist Auke-Florian Hiemstra, bird nests tell the story of a rapidly changing world while also holding up a mirror to us humans. During the European Researchers’ Night, an annual science festival that brings science closer to the public, he will share his remarkable stories as a guest speaker. Here’s a preview of the festival on 26 September.

Text: Jelle Posthuma

Biologist Hiemstra, PhD at Naturalis and affiliated with Leiden University, will talk about urban nature. ‘When people say: ‘I’m going into nature’, they often mean leaving the city. Yet cities are teeming with nature – sometimes even more so than the surrounding countryside.’ Hiemstra specialises in nest research. ‘Nests are incredibly exciting,’ he says enthusiastically. ‘They are built by animals, but they also tell the story of us humans and of a changing world.'

New nests

He cites the coot as an example, a bird he has studied extensively. ‘The first Dutch bird books from the 18th century show beautiful illustrations of coot nests. The bird itself hasn't changed over the centuries, but the nests are completely different. A modern-day urban coot would not even recognise an 18th-century nest as a nest.’

That’s because the coot’s habitat has changed drastically. Whereas water birds used to mainly use organic materials such as reeds, they now build their nests with things left behind by humans, from McDonald's bags to plastic sweet wrappers. ‘The nest tells the story of a changing world and of human influence. We now speak of the Anthropocene, the era in which humans shape and irreversibly alter the environment.’

Throw-away society

One of Hiemstra’s best-known discoveries is the so-called Rokin nest, named after the spot in Amsterdam where it was found. According to him, this coot’s nest can be read as a history book. It was built almost entirely from plastic materials, with each sweet wrapper precisely datable, simply because plastic does not decay. ‘The deeper we looked into the nest, the further back in time we went. The bottom layers turned out to be from the early 1990s, only a few years after the coot was first seen in Amsterdam. The entire story of the coot in the city was stored inside this nest.’

The nest also reveals how humans deal with plastic. ‘In the 1960s we thought plastic was fantastic – a material that lasts forever! But by now it has become a disaster. We have started to use it as a throwaway product. I’m not at all against plastic, but why use a material that lasts forever for something you throw away after a single use? Something has gone terribly wrong there.’

A mirror to humanity

There is much we can learn from the coot, Hiemstra argues. On a plastic nest, a coot can breed for decades: recycling at its best. ‘Building such a nest costs the coot much less energy. Each year only a few new materials need to be added – as if you were making your bed again.' People tend to find the sight of such a plastic nest rather sad. However, Hiemstra cites a swan's nest, also built in our capital city, which was filled with plastic. 'All the eggs hatched, and all the young grew up. It was a hugely successful nest for the birds.’

At the same time, plastic poses a threat to nature, the biologist continues. ‘What about microplastics for the birds, or the risk of entanglement in plastic material? These are major questions we still need to investigate.’ Above all, plastic nests hold up a mirror to humans. ‘It’s actually quite embarrassing that we have to learn from birds how to reuse plastic. For the coot, it isn’t waste but a valuable resource. If only humans were more like coots, I sometimes say.’

Creative animals

Although we need to think carefully about how we handle materials, Hiemstra mainly wants to share remarkable, positive stories in his lecture. For example, he tells of the magpie, which builds its nest from anti-bird spikes – the very metal prongs designed to keep birds away. ‘That says so much about the creativity of the magpie. It’s the perfect revenge: the birds reclaiming their own space.’

People often make a strict distinction between ‘human things’ and ‘animal things’, says Hiemstra. ‘But nests show that this separation doesn’t really exist. Birds do ‘animal things’ with human materials. With my lecture, I also want to open people’s eyes to urban nature: to the things you encounter on your way to work.’

The evening’s programme

European Researchers’ Night at the Forum features more than 55 activities spread across four floors, including over 35 different science shows, talks, and science battles, combined with dance and music. The programme includes interactive experiments, science quizzes, and lectures by a wide range of scientists.

In the afternoon, Auke-Florian Hiemstra will also give a special lecture for school pupils, as part of the schools’ programme. In the evening, he will deliver his public lecture in the Rabo Studio at 20:00. Visitors are advised to book a ticket in advance via the Forum Groningen website.

The programme was created by: RUG Schools for Science and Society, Studium Generale, University Museum, Young Academy Groningen, Science LinX, Forum Groningen and BKB | Het Campagnebureau.