Demographics and song repertoire sizes of cirl bunting populations

We recorded cirl buntings in 2011 and 2019 at eight locations in Devon (Source) and one in Cornwall (Reintroduced), all within the UK. We recorded songs as WAV files with a sampling rate of 44.1 KHz using a Sennheiser ME66 directional microphone and Marantz Solid State Recorder PMD661 between 0730-1700h throughout May - August in 2011, and June - July in 2019. We identified songs using spectrograms (FlatTop window; FFT 512, frequency resolution 86 Hz, 93.75% overlap – time resolution 0.72 s) in Avisoft SasLab Pro (Specht, 2002). A library of 54 unique syllable types was created, representing the song types of all individuals recorded. Each individual song spectrogram was visually compared with the reference library of the 54 syllable spectrograms for classification (Fig.4 in the results shows a range of the different syllable types). For each population we calculated the number of different song types (PopRep). We then calculated the Dice sharing index (Dice, 1945) between all possible pairs of populations using the following formula.