General Protocol: Cowbirds and Nest Predators

We are interested in the effects of cowbird parasitism and nest predation on forest-bird breeding success. Listen for displaying male cowbirds (males advertising to attract a female) and be alert for the drab females; they can be inconspicuous. For more information on the Brown-headed and Bronzed cowbirds, see the References: Species Accounts section of the manual.

Only record information on cowbirds and predators if you detect these species during the 10-minute Observation Period. Participants across the country will spend varying amounts of time in the field depending on the number of species they study. Consequently, the amount of observation time must be controlled because it affects the probability of detecting birds. Recording only the observations made during the 10-minute Observation Period standardizes the amount of effort (time) spent by each BFL participant. If you encounter cowbirds or predators (see list of potential predators on the front side of the Field Form), please record this information on your Field Form and later when entering your data on the BFL website. If you wish, you can report cowbirds or predators that were observed outside the 10-minute Observation Period in the “Comments” section of the data form. Also, if you keep track of other avian species that are not listed in the “Nest Predator” column, please list these species in the comments section of the Field Form.