Breeding Bird Survey

The Breeding Bird Survey monitors the status and trends of bird populations. Data from the survey are an important source for the range maps found in field guides. The North American Breeding Bird Survey is a joint project of the United States Geological Survey (USGS) and the Canadian Wildlife Service. The UK Breeding Bird Survey is administered by the British Trust for Ornithology, the Joint Nature Conservation Committee, and the Royal Society for the Protection of Birds.
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