A COMPARISON OF TECHNIQUES FOR MARKING PASSERINE NESTLINGS

Abstract We examined eight marking techniques designed specifically for use on newly hatched Red-winged Blackbird (Agelaius phoeniceus) nestlings (colored polishes applied to either the culmen or the hallux; colored elastic, plastic, or band-aid bands applied to the tarsus; stains applied to either the superciliary down or the tarsus; and superciliary down clipping) to determine which technique had the shortest application time and longest retention. Application times and retention rates varied between marking techniques, but this did not affect nestling growth or survival. Clipping of superciliary down feathers had the shortest application time and the highest retention rate of all techniques studied. This technique, however, is only applicable to species whose newly hatched young have superciliary down. Other techniques examined had comparably short application times, but were not retained for the entire nestling period.