Black-headed Tailorbird

Black-headed tailorbirds are dark tailorbirds with a characteristic head pattern. The body mass ranges from 8–14 g (0.28–0.49 oz), with an average of 10.3 g (0.36 oz), and is roughly equal in both males and females. Older sources erroneously state the mean body mass as being 7 g (0.25 oz). Birds from Mindanao have a lower average body mass, 10.1 g (0.36 oz), than birds from Dinagat and Siargao, who have an average body mass of 10.6 g (0.37 oz). The average adult length is 12 cm (4.7 in). In O. n. nigriceps, the average wing length is 48.3 mm (1.90 in), the mean bill length is 10.8 mm (0. Voice: The tailorbird's call is a series of lengthy, stuttering trills that slows as it flattens out. It is like the song of the yellow-breasted tailorbird, but has a more "metallic ringing quality". Other calls include an anxious, falling ssiirrrrpppppp and a ringing key-e ei, the second of which is similar to the long-tailed bush warbler's song.