An often overlooked threat to birds is the constant, and ever increasing noise pollution that is affecting bird species where they live in proximity to humans. Studies have shown that both adults and nestlings show multiple signs of chronic stress in areas of high noise pollution, including skewed stress hormone levels, possibly due to increased anxiety, distraction and hyper-vigilance. Constant noise can muffle the audio cues birds rely on to detect predators, competitors and even their own species (important during the breeding season). Unable to discern whether their environment is safe, mother birds in noisy areas often must choose between staying on guard at the nest and finding food for their young, which can lead to decreased growth and fitness of their offspring. During migration seasons (spring and fall) it is recommended we minimize outdoor noise as much as possible.