Warbling Masked Flowerpiercer

The masked flowerpiercer grows to a length of about 15 cm (6 in). The adult male is deep ultramarine blue with a dark mask. The beak is large, black, and upturned, with a characteristic hook on the tip of the upper mandible. The iris is bright red. The female is similar in appearance but altogether duller. The juvenile has a reddish-brown iris. At the northern end of its range, the song is a series of reedlike notes terminating in a twitter, while at the southern end, it is a jangling series of high-pitched notes ending with several lengthy "tseee" notes. These differing songs suggest that the northerly and southerly populations may be different species.

The masked flowerpiercer is endemic to the Andes in South America where its range extends from Venezuela and Colombia, through Ecuador and Peru to Bolivia. It inhabits montane forest, cloud forest, secondary forest, scrubby woodland and forest edges, at altitudes between about 2,000 and 3,500 m (6,600 and 11,500 ft).

This bird is often seen in small groups or mixed flocks, foraging through the foliage for insects and fruit, and probing into flowers with its beak. The flowers of the small tree Axinaea sclerophylla are pollinated by birds, the pollen being liberated in a puff when the stamens are manipulated. During a research study, the only bird seen visiting the flowers was the masked flowerpiercer, which proceeded to pull off and consume the stamens, one at a time. Breeding takes place between June and September in Colombia, but in other parts of the range, juveniles have been seen at various times of year. The nest is a cup-shaped construction, built in a bush, and composed of mosses and dry grasses and lined with feathers. The eggs are pale bluish-green blotched and speckled with reddish-brown.