 The songs of the four subspecies of common firecrest ( nominate R. i. ignicapillus , Mediterranean R. i. balearicus , southeastern R. i. caucasicus and North African R. i. <unk> ) show a number of different song forms , but in general are very similar to each other , whereas the Madeiran firecrest has only one song type , which is divided into three phrases , two of them consisting of modified display and anger calls . Its display calls use a larger frequency range and more harmonics than the continental subspecies . Male common firecrests do not show a territorial response to recordings of the songs or calls of the Madeiran taxon , although Madeiran firecrests do react strongly to playback of the calls of the mainland birds . The island form was recognized as a separate species on the basis of differences from the mainland form in morphology , vocalisations , and genetics . 
