Red-headed Myzomela

While the social organisation of the red-headed myzomela is relatively unknown, it is reported as being usually solitary or found in pairs, though it has been described as forming loose associations with brown honeyeaters, and other mangrove-feeding birds such as the northern fantail and yellow white-eye. It is an inquisitive bird and readily responds to pishing, coming close to the caller to investigate the source of the sound and to warn off the intruder. It calls throughout the day when feeding, and males sing from exposed branches in the upper canopy of the food trees. The red-headed myzomela actively defends food trees, engaging in aggressive bill-wiping both in response to a threat and after chasing intruders from a tree. It is very antagonistic even towards its own species; the males fight by grappling in mid-air and falling close to the ground before disengaging. It constantly chases brown honeyeaters through the canopy, though it has not been observed in grappling fights with other species.

The nominate subspecies of the red-headed myzomela is distributed across the tropical coastlines of Western Australia, the Northern Territory and Queensland. It inhabits coastal areas of the Kimberley and various offshore islands in Western Australia, and is similarly distributed in the Northern Territory, including Melville Island and the Sir Edward Pellew Group of Islands. It is widespread around the coast of the Gulf of Carpentaria and the Cape York Peninsula. M. e. infuscata occurs at scattered sites in West Papua and in south Papua New Guinea, from the Mimika Regency in the west to the Fly River in the east, and the Aru Islands. Some birds of Cape York have features intermediate between the two subspecies. Although the red-headed myzomela is widely distributed, it is not abundant within its range. The largest recorded population was 5.5 birds per hectare or 2.2 per acre at Palmerston in the Northern Territory. The peak abundance of the species in the mangroves around Darwin Harbour during the mid-dry and early wet season coincided with the production of young and the flowering of the yellow mangrove (Ceriops australis). The species' movements are poorly understood, variously described as resident, nomadic or migratory. Population numbers have been reported as fluctuating in some areas with local movements possibly related to the flowering of preferred mangrove and Melaleuca food trees, and there is some indication that the birds can travel more widely. A single bird was recaptured after being banded nearly five years earlier, 27 kilometres (17 mi) from the original banding site, and the species' occupation of a large number of offshore islands suggests that the red-headed myzomela is effective at crossing distances over water. The maximum age recorded from banding has been 7 years 1.5 months. The red-headed myzomela mostly inhabits mangroves in monsoonal coastal areas, especially thickets of spotted mangrove (Rhizophora stylosa), smallflower bruguiera (Bruguiera parviflora) and grey mangrove (Avicennia marina) bordering islands or in river deltas, but it often also occurs in paperbark thickets fringing the mangroves such as those of cajeput (Melaleuca leucadendra). It is a mangrove specialist, an adaptation that probably occurred as northern Australia became more arid and the bird populations became dependent on mangroves as other types of forest disappeared. The mangroves provide nectar and insects as well as shelter and nesting sites, and they supply the majority of the species' needs for most of the year. In Australia, mangrove vegetation forms a narrow discontinuous strip along thousands of kilometres of coastline, accommodating birds specialized for the habitat. Eighty Mile Beach in Western Australia has no mangroves and no fringing Melaleuca forests, reducing its potential for successful colonization by nectarivores, and it marks the southern limit of the red-headed myzomela in Western Australia. The red-headed myzomela is occasionally found in swampy woodlands, casuarina woodlands and open forest, particularly those with Pandanus and paperbarks, as well as on coconut farms.

M. e. erythrocephala is listed as being of least concern by the IUCN, because the population is widespread. However, the Australian population of M. e. infuscata is listed as near threatened, since it is confined to three small islands with a combined area of about 100 square kilometres (39 sq mi). There is no immediate threat to the red-headed myzomela, except the risk posed to low islands by rising sea levels; however, it has been recommended that community-based ecotourism on the tropical coast be promoted, as it could lead to monitoring of sub-populations and habitat by visiting birdwatchers and local rangers.