The Papuan black myzomela is a diminutive bird, measuring a mere 12–13 cm in length. The males of the species are distinguished by their lacquer-black plumage and contrasting white underwing-coverts. Females, on the other hand, are adorned in more subdued tones of drab brown, with a distinctive reddish hue gracing their forehead and throat. However, this red is conspicuously absent from the tail. Intriguingly, some females exhibit a sooty black visage devoid of any red, and in the southeast regions of their range, it is not uncommon to encounter females that are entirely black. Juveniles bear a resemblance to the darker or grey-brown females.
When attempting to identify the Papuan black myzomela, look for the stark sexual dimorphism between males and females. Males are unmistakably black with white underwing-coverts, while females are generally brown with a reddish forehead and throat. The size of the bird and the habitat it frequents can also aid in identification.
The natural abode of the Papuan black myzomela is the subtropical or tropical moist lowland forests and savannah woodlands. These birds have a particular affinity for flowering trees, such as albizias and eucalypts, where they are often spotted.
This species is endemic to New Guinea and its adjacent islands, where it flits through the forest canopy and savannah woodlands.
Observations of the Papuan black myzomela's behaviour are limited, but like many of its congeners, it is likely to be active and nimble in its movements, particularly when foraging among the blossoms of trees.
The vocalizations of the Papuan black myzomela are not well-documented, but as a member of the Meliphagidae family, it may have a repertoire of melodic calls and songs used for communication and territorial defense.
Specific details on the breeding habits of the Papuan black myzomela are scarce, but they are likely to follow patterns similar to other myzomelas, involving the construction of small, cup-shaped nests where they lay their eggs.
In regions where the Papuan black myzomela's range overlaps with other myzomelas, careful observation is required to distinguish between species, particularly among the females which may share similar brownish plumage.
The Papuan black myzomela is presumed to feed on nectar, given its association with flowering trees, and may also consume small insects as part of its diet.
The IUCN Red List has classified the Papuan black myzomela as Least Concern, indicating that, at present, there are no immediate threats to its population numbers that would warrant a more dire conservation status.