In 2023, a global study found litter in the nests of 176 different bird species, with common culprits including cigarette butts, plastic bags and fishing nets. Melbourne, It’s spring, and Australian birds are building their nests. But with what? Alongside grass and twigs, birds are collecting our rubbish.
In designing their nests, birds respond to the natural environment in ingenious ways. As their local environments have changed over time, birds have adapted, incorporating human-made materials. Most of these additional materials were plastics. The damage from human-made materials can also be less visible. In Mexico, house finches line their nests with cigarette-butt fibres, which repel nest parasites – themselves a significant threat to birds and particularly chicks. A study found that while nests with cigarette-butt fibres resulted in better hatching and fledgling success, the chicks showed increased signs of genetic damage. Birds are already struggling. One in six Australian bird species are nationally threatened, with land clearing, cat and fox predation and changes in climate the most serious threats. Peckable Architecture asks what the built environment might look like if we designed it with bird welfare in mind. Our bricks use materials that local birds in Melbourne, such as superb fairy wrens and grey fantails, typically use. At the installation sites at Fed Square and Royal Botanic Gardens, we’ve installed motion-activated cameras to record which bird species visit and which materials are taken away.
A study of more than 700 nests held in museum collections found that those from rainy places had thinner walls to dry out faster, and open cup nests from windy places were often deeper, to keep eggs from blowing away. A study of 893 nests from Australian museum collections, representing 224 species, found the occurrence of human-made materials in bird nests rose from 4 per cent in 1832 to 30 per cent in 2018. In Portugal, a study on white storks found 91 per cent of nests included human-made materials. Over a period of weekly monitoring, 12 per cent of the nestlings became entangled, most commonly in baling twine.
