1. Response of reed warbler and sedge warbler to acoustic playback in relation to age, sex, and body condition
- Author
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Dariusz Jakubas, Katarzyna Wojczulanis-Jakubas, and Jakub Wietrzykowski
- Subjects
0106 biological sciences ,biology ,Ecology ,Zoology ,biology.organism_classification ,010603 evolutionary biology ,01 natural sciences ,Sedge warbler ,010605 ornithology ,Warbler ,Sex bias ,Acrocephalus ,Sex ratio ,Body condition - Abstract
Acoustic playback has been shown to substantially increase the number of birds trapped. However, other effects of playback have rarely been investigated; the few studies that have been published strongly suggest that when playback is applied some groups of birds may be captured more easily than others, leading to biased results. In this study, we evaluated the experimental effect of acoustic playback (by comparing days when playback was used and was not used) at a stop-over site in central Europe during the post breeding period and the autumn migration. We examined the influence of playback on numbers of birds captured, i.e., two reedbed passerines—the reed warbler Acrocephalus scirpaceus (RW) and the sedge warbler A. schoenobaenus (SW)—with respect to their age, sex and body condition. We found that playback increased the number of birds captured 2.5 times in RW and 3.6 in SW. We did not find evidence for a differentiated response to the acoustic stimuli between adults and immatures. The sex ratio in RW was not affected by acoustic playback, but we did record significant male-bias in SW. The body condition of lured and non-lured birds was similar in both species. The sex bias revealed in one species but not in the other, clearly shows that great caution should be exercised when using playback to attract various species.
- Published
- 2015