Mobbing responses of passerines from playback of predator and nuclear species alarm call
The mobbing response is an effective and aggressive antipredator strategy for many bird species. Most studies have used visual or auditory signals of certain species to attract passerines and to elicit mobbing responses. However, few studies discuss signal types and species' differences in responses. In this study, we used the specimen and call of the Collared Owlet (Glaucidium brodiei) as a predator signal, and we used the alarm call of Morrison's Fulvetta (Alcippe morrisonia) as a nuclear species' signal to investigate differences in mobbing responses from small passerines. We combined (1) visual and auditory signals and (2) predator and nuclear species to create six experimental treatments. We conducted playback experiments at 24 sites in low-altitude forests of Taiwan using a Latin Square design from March to May 2020 (breeding season) and December 2020 to February 2021 (non-breeding season). We used probability of response, response level, latency of response, and duration of response to compare differences in mobbing responses between signals. We conducted 263 experiments and recorded 408 individuals of 29 species that attended the mobbing events. In both seasons, "Visual only" had a lower attendance probability (i.e., probability of attending the mobbing event) than "auditory only", which indicated that auditory signals attracted more individuals. "Combination of visual and auditory signals" had the same responses as "auditory only" in both seasons, which implied that visual signals were a weak attraction. "Collared Owlet's call only" received a higher attendance probability than "Morrison's Fulvetta's alarm only" in the non-breeding season, but not in the breeding season, which suggested that predator threats were season-dependent. Our results also provided evidence regarding the role of Morrison's Fulvetta as a nuclear species. Further studies are needed to understand how mobbing responses and mixed-species flocks can be influenced by the environment, species composition, and species traits.
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Data were collected using playback experiment on 6 different treatments. In addition to the date, time, and location, we recorded treatment, species, number of individual, closest distance, attending mobbing or not, mobbing level, latency time, and his is a freeform section for you to describe how the data are structured and how a potential consumer might use them. Be as descriptive as necessary. Keep in mind that users of your data might be new to the field and unfamiliar with common terminology, metrics, etc.