North American Breeding Bird Survey Dataset 1966 - 2017, version 2017.0

The 1966-2017 North American Breeding Bird Survey dataset contains avian point count data for more than 700 North American bird taxa (primarily species, but also some races and unidentified species groupings). These data are collected annually during the breeding season, primarily June and May, along thousands of randomly established roadside survey routes in the United States and Canada. Routes are about 24.5 miles (39.2 km) long with counting locations placed at regular intervals, for a total of 50 stops. At each stop, a person highly skilled in avian identification conducts a 3-minute point count, recording every bird seen within a quarter-mile (400-m) radius and every bird heard. Surveys begin 30 minutes before local sunrise and take approximately 5 hours to complete. A route is sampled once per year, with the total number of routes sampled per year growing over time; about 600 routes were sampled in 1966, while in recent decades approximately 3000 routes have been sampled annually. In addition to avian count data, this dataset also contains date route sampled, survey start and end times, start and end weather conditions, a unique observer identification number, route identification information, route location information including geographic coordinates of route start point, and an indicator of sample quality.