Melampitta

The melampittas are a family, Melampittidae, of New Guinean passerine birds containing two enigmatic species. The two species are found in two genera, the greater melampitta in the genus Megalampitta and the lesser melampitta in the genus Melampitta. They are little studied and before being established as a family in 2014 their taxonomic relationships with other birds were uncertain, being considered at one time related variously to the pittas, Old World babblers and birds-of-paradise.

These are small to medium-sized birds with black plumage, strong legs and short, rounded wings. Mostly terrestrial, they live in montane forest. The greater melampitta has more specific habitat needs, roosting and nesting in limestone sinkholes. Insects and small vertebrates are taken from the forest leaf litter. Little is known about their breeding behaviour, with only the nests of the lesser melampitta having been seen by scientists. Both species are considered to be safe from extinction.

The taxonomic placement of the melampittas was the source of long-standing confusion. Based on its superficial resemblance to the suboscine pittas (plump bodies, short tails and long legs), Hermann Schlegel placed the lesser melampitta within that family when he described that species in 1871. The name melampitta is derived from the Ancient Greek melas- for "black" with the genus name "Pitta". As Ernst Mayr demonstrated that the structure of the syrinx was that of an oscine bird, the genus was later moved to the Old World babblers (an infamous "taxonomic dustbin"), then with the jewel-babblers and whipbirds, which have been placed in both the Orthonychidae or the Eupetidae (but are now in their own family, Cinclosomatidae).

Based on the analysis of DNA–DNA hybridization data the genus was placed with the Paradisaeidae birds of paradise by Charles Sibley and Jon E. Ahlquist. Frith and Frith felt these conclusions were not supported by aspects of the behaviour and biology (although they argued it may have been related to the recently split Cnemophilidae birds of paradise). More recent studies have refuted the relationship with the whipbirds and jewel-babblers, and instead consistently shown a relationship as the sister taxa to a group of families including the drongos, fantails, monarch flycatchers, Corcoracidae (the white-winged chough and apostlebird of Australia) and the birds of paradise again. The fact that the melampittas do not closely resemble these families (except the Corcoracidae and to a lesser extent the birds of paradise) may be due to adaptations to terrestrial living, compared to the other families which are mostly arboreal. Given the distinctiveness of the two melampittas it was suggested that the genus be placed its own family, and a new family, Melampittidae, was formally erected in 2014 by Richard Schodde and Leslie Christidis.

While most researchers also accepted that the two species are congeneric (are both in the same genus), the two species do have a number of differences, particularly size, tail length and calls. In 2014, in the same paper that established the family, Schodde and Christidis moved the greater melampitta into its own genus Megalampitta. Although the name was created to invoke the Greek mega for large and Melampitta for the genus, the authors of the paper stated that, per the Code for Nomenclature, it should be treated a random collection of letters. The authors also noted that it is possible that the two species may be separated into two families in the future.

The greater melampitta is monotypic, meaning it has no subspecies. The lesser melampitta has had three subspecies described, distinguished by slight differences in measurements, so more recent treatments have also treated it as monotypic. A study published in 2024 confirmed that the greater melampitta is indeed monotypic, with all birds forming a single population, even though they have a highly dispersed population. The lesser melampitta showed deep divisions between the three populations, leading the researchers to suggest that it may represent three different species.

The melampittas are birds of the New Guinean rainforest and are generally montane species as well, with the range of the lesser melampitta reaching as high as 3,500 m (11,500 ft), with a usual range of around 2,000 to 2,800 m (6,600–9,200 ft), where it is found in around watercourses and other damp areas. The greater melampitta is restricted to areas of rugged limestone karst with sinkholes that it apparently roosts and even nests in. In the Kumawa Mountains Jared Diamond found that that species inhabited a range of 650 to 1,400 m (2,130–4,590 ft). Both species have a discontinuous distribution across New Guinea, with the valleys between the highland ranges creating sky islands. The greater melampitta in particular is seldom encountered by scientists because its karst habitat is rarely visited due to the difficult terrain.

The distribution of the lesser melampitta is consistent with the usual pattern of evolution in birds in New Guinea, with older species of birds inhabiting the highlands which act as refugia, a phenomenon known as taxon cycles. The distribution of the greater melampitta is harder to explain, as it is also an ancient species, but is found at lower altitudes. The greater melampitta also has much more isolated populations, but lacks the genetic differentiation between these populations that their isolation and poor dispersal ability would imply.