The records include avian point count data for all reported taxa (species, races, and unidentified species groupings). In addition to avian count data, this dataset also contains survey date, survey start and end times, start and end weather conditions, a unique observer identification number, route identification information, and route location information including country, state, and BCR, as well as geographic coordinates of each route's start location.
These data were collected annually during the breeding season, primarily in May, June and July, along randomly established roadside survey routes in seven states in northern Mexico (Baja California Sur, Baja California, Sonora, Chihuahua, Coahuila, Nuevo León and Tamaulipas). Routes are roughly 24.5 miles (39.2 km) long with counting locations placed at approximately half-mile (800-m) intervals, for a total of 50 stops. A brief summary of the methodology is as follows: 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, or heard at any distance (excluding birds believed to have been recorded at a previous stop). Surveys begin 30 minutes before local sunrise and take approximately 5 hours to complete. Routes are sampled once per year.
NOTE: The data in this release include all records reported. They have not been subjected to the rigorous quality control screening that BBS data from the U.S. and Canada receive. Therefore, these data are NOT intended to be lumped with U.S. and Canada data for pooled population analyses.
