In early to midsummer of 2021 there were cases of a mysterious illness affecting songbirds in some Middle Atlantic States. As a measure of precaution, a number of states including New Hampshire recommended that people take in their feeders and wash them with a solution of 90% water and 10% household bleach. In the middle of August, the mysterious illness began to subside in the Mid-Atlantic States. These states gave the green light to put out feeders as the number of cases declined substantially. States up the east coast followed along.
Although NH Fish and Game has not reversed its recommendation regarding bird feeding, any risk New Hampshire might have faced from this illness appears to have passed. Bears remain a significant threat however, especially given the mild fall, and NH Fish and Game still recommends not putting feeders out until after December 1. People should wait to resume feeding until danger of bears in their area is past. This is likely to be dependent on local conditions that will vary significantly between the northern and southern parts of the state.
No cause has been identified for the illness. Sick or dead birds may still be reported to NH Fish and Game.