Carrion crows and Eurasian magpies use anti-bird spikes as nest-building materials, according to a study published in the Online Journal of the Natural History Museum Rotterdam. These metal pins, typically intended to deter birds, are sometimes a primary component in their nests.
Historically, birds have demonstrated their flexibility by using man-made materials, such as nails, screws, knitting needles, barbed wire, and even discarded syringes, for nest construction.
The study found that these birds not only incorporate anti-bird spikes in their nests, but also position them strategically, possibly as a defense against predatory birds known for targeting magpie eggs and offspring.
From the article:
Ironically, the rows of upward pointing anti-bird spikes may be an appropriate substrate for a nest, as the pins help to secure the twigs and support the structure, especially on sloping surfaces (Vrielink 2021). Another classic example of such 'bird rebellion' is the Australian 'Parkdale Pigeon,' which fought against anti-bird spikes by building a nest on top of them, as documented by Twitter user Michael Bell. This pigeon's nest was repeatedly removed, but the more bird spikes were installed, the better the foundation of the new nest became. Some birds go even a step further, and tear bird spikes off buildings themselves.
The article includes photos of the nests made from anti-bird spikes.
