What constitutes a bird rare enough to require special documentation? The New Hampshire Rare Birds Committee (NHRBC) reviews reports of rare birds and has established a list of species requiring documentation and review. In addition, any species not previously seen in New Hampshire would automatically be added to this list. Other birds need to be documented only under unusual circumstances. These include:
- birds seen at times of the year they are not supposed to be here (e.g., a Snowy Owl in the middle of the summer or a Yellow Warbler in the middle of the winter)
- migratory birds seen unusually early or late in the migration season (e.g., a Barn Swallow lingering into December or a Red-eyed Vireo arriving in early April)
- birds seen in locations where they are not supposed to be (e.g., a Red-throated Loon in the snow in the White Mountains or a Boreal Chickadee in Salem)
- and birds seen in very large numbers compared to their normal abundance (e.g., 35 Bald Eagles circling together overhead)
Two very useful guides about the commonality of birds at various times of the year that will help determine a bird’s rarity are The Atlas of Breeding Birds in New Hampshire (C. Foss ed.) and A Checklist of the Birds of New Hampshire (Hunt et al. ed.), both available from New Hampshire Audubon, in the Concord Nature Store.