Sedge Warbler (Acrocephalus schoenobaenus) Science Article 3
Tape-luring often is used in studies of bird migration, and the technique can strongly augment the total number of birds captured. Additional captures from tape-luring could result from increasing the capture probability of birds already at the stopover site, or from attracting birds that normally would have overflown the stopover site. We conducted an experiment in which we captured night-migrating Eurasian Reed-Warblers (Acrocephalus scirpaceus) during 32 consecutive days, using tape-luring every fourth night, on average. Based on recruitment analysis (a class of Cormack-Jolly-Seber models), average capture probability was one to four times higher on days with tape-luring. The probability that a bird was a new arrival at the stopover site varied between 50% and 85% on days with tape-luring and was almost zero on control days without luring. Because tape-luring can influence where and when migrants choose to land, answers to biological questions about migration could be compromised by data from tape-lured birds.
Mich l Schaub, Regine Schwilch and Lukas Jenni, Auk: Vol. 116, No. 4