The parents, who were caring for the chicks, were not exposed to the traffic noise or calls. The results showed that average-sized eggs exposed to traffic noise were 19% less likely to hatch than those exposed to bird calls. Additionally, although larger eggs are usually easier to hatch, exposure to traffic noise also made them less likely to hatch than smaller eggs. Moreover, the adverse effects of exposure to traffic noise from just before hatching until a few days after hatching persisted even after the chicks were no longer exposed to the noise. By the time the chicks reached breeding age four years later, the birds exposed to traffic noise early in their lives had produced less than half the offspring of the other birds.

Source: The Guardian May 25, 2024 13:00 UTC