The principal territorial song of the Fernwren is a series of long, punctuated clear shrill whistles, seemingly repeated ad infinitum. Each of these samples is limited by the website design to a max. of 1 mb of MP3 which equals just over a half a minute of recording, so I have tried to convey a better idea of the song by making samples 200-020, 200-040 and 200-055 follow on from one another. Even so, this is just a part of the song sequence - the bird actually continued uninterrupted for more than two and a half minutes, gradually getting lower and lower in pitch, like his battery was running out, or his spring needed winding! Sample 200-070 contains two quite different calls which followed on from one another, the first a harsh grating call (very like one of the Northern Scrub-robin) and the next, a single clear note. The function of these is not known, but there were two birds present, presumably the pair. They were aware of our presence so the harsh call may be one of mild alarm. Sample 200-100 is a call which is rarely heard, rather un-Fernwren like, but I have recorded it in two different places. There is a more distant whistling song in the background which I suspect is a bird from a neighbouring territory. According to HANZAB Fernwrens have quite a wide variety of calls - these examples are just a few.