It's not surprising that birds react to loud sounds, but a 2023 study quantified the number of birds impacted by New Year's Eve fireworks, the energy these startled birds expend, and the changes to their feeding in the aftermath.
They used weather radar to track birds in the air and found that around their study site in the Netherlands, 384,000 birds took off at the start of the fireworks and were still flying hours later. They suggest that larger birds such as geese, ducks and gulls flew very high and continued to fly hours later.