Behaviour 2019
Social facilitation through acoustic signals in mixed-species wintering flocks
Faiza Hafeez, Laura Vander Meiden, Allison Elaine Johnson, Stella Uiterwaal. University of Nebraska-Lincoln, Lincoln, NE, United States

Several woodland resident species in North America form mixed-species flocks in winter. Social associations in mixed-species flocks can facilitate foraging by providing information about novel food resources. We tested the hypothesis that different species’ calls are used to facilitate foraging through expedited food finding, and that individuals differ in their use of heterospecific information. We paired novel feeder sites with playbacks of ‘chicka’ calls of black-capped chickadee, ‘quank’ calls of white-breasted nuthatch, or white noise controls. We then tracked the arrival of birds at feeders using video and RFID dataloggers over 1.5 hours. We observed the arrival of black-capped chickadee (Poecile atricapillus), white-breasted nuthatch (Sitta carolinensis), downy woodpecker (Picoides pubescens), red-bellied woodpecker (Melanerpes carolinus), and American goldfinche (Spinus tristis). The preliminary results show that latency to arrival at a novel feeder site was shortest for the ‘chicka’ call treatment, suggesting that this call functions in social facilitation. Further experiments can reveal more about the role of acoustic signals in social facilitation for foraging.