Summary: European corvids have been observed incorporating anti-bird spikes into their nests, taken from buildings in urban areas. Researchers documented this behavior in a study published by the Dutch journal Deinsea, noting that the spikes were used in both structural and potentially defensive ways. The unusual nests raised questions about the birds’ adaptation to human-made environments. While fascinating, the researchers caution that anti-bird spikes can harm wildlife, such as impaling birds and causing injuries. The surprising discovery highlights the unsettling prevalence of these spikes in urban settings and calls for a reconsideration of human interventions that disrupt natural habitats.
https://www.audubon.org/magazine/apparently-magpies-and-crows-are-using-anti-bird-spikes-make-their-nests