Chestnut-bellied Flowerpiercer

Chestnut-bellied flowerpiercers, like the other birds in the genus Diglossa, are small montane tanagers. Their slender upturned bills are used to pierce flowers at the base to obtain nectar. Size: 14-15cm in length. Wingspan is 75mm (male), 70mm (female). Adult Male: The head, upper breast, nape, back, wings and tail are deep glossy black. The lesser wing-coverts are bluish-grey and there is a wash of this colour on the rump. The lower breast, belly and vent are deep rufous-chestnut with black markings on the flanks. The undertail coverts are black. The bill is black and the feet and tarsi are grey. Adult Female: Similar to the male, but the rump shows more bluish-grey colour. Juvenile: Similar to the adults but the black areas are duller, the lesser wing-coverts and rump are black, the chestnut areas are marked with black streaks, and the lower mandible is yellow with a dark tip. Subspecies variation: Subspecies D. g. boylei differs from the nominate subspecies by showing uniformly chestnut flanks, sides, and undertail coverts.

This species is known from only a few small and discontiguous locations in the highlands of the Western Andes of Colombia. Populations have been observed in recent years in the departments of Antioquia (Paramillo Massif, Páramo de Frontino, Jardín area, Páramo del Sol, and Farallones del Citará); Cauca (Serranía del Pinche and southwest of Popayán); Chocó (Gorrión Andivia Bird Reserve); and Risaralda (Cerro Montezuma in the Parque Nacional Natural Tatamá). Given that much of the potential range of this species is in high and remote areas, it is possible that additional populations remain to be found. Chestnut-bellied flowerpiercers are found at elevations between 3000 and 3800m, except for at the Cerro Montezuma where they regularly occur down to 2400m. The typical habitats are open páramo, shrubby sub-páramo and the edges of elfin forest. The species is known to favour shrubby forests of Polylepis species including Polylepis quadrijuga, and other small trees such as Escallonia or Baccharis.

Due to the remoteness of and, until recently, high levels of guerilla activity within the area, the birds of higher altitudes in the northern portion of the Western Cordillera have not been sufficiently studied. The chestnut-bellied flowerpiercer is no exception – there were no records of the species between 1965 and 2003. Thus there is relatively little known about its ecology. Breeding. Evidence of reproduction, including females in breeding condition and the construction of nests suggests that breeding periods occur in February and August. Feeding. At one páramo site the species was observed feeding on the flowers of some Melastomataceae and Ericaceae species, mainly of the genera Cavendishia, Psammisia andThibaudia, as well as Loranthaceae and epiphytic bromeliads. Like the other flowerpiercers it probably also forages for small insects. At the Cerro Montezuma location they have been observed visiting hummingbird feeders. Behaviour. This is a territorial species that only forms pairs when it nests. It has been observed moving in family groups of up to five individuals and also associating with mixed flocks. At Páramo Frontino chestnut-bellied and black-throated (Diglossa brunneiventris) flowerpiercers hold mutually exclusive territories.