Tahiti monarch  (Pomarea nigra)

Less than 50 of this small, monochrome songbird remain, but an intensive recovery programme may be able to pull the species back from the verge of extinction (3). Both males and females have a plumage that is metallic black, with bluish-grey legs and a pale blue bill. Immature Tahiti monarchs, or flycatchers, differ by having reddish-cinnamon plumage and grey legs and bill. Its song is a strong and complex flute-like melody, whilst its alarm call is a sharp tick-tick-tick sound (2).

Found only in four valleys on the west coast of Tahiti, the largest of the Society Islands, in the southern Pacific Ocean (2).

The Tahiti monarch occurs in subtropical and tropical forest, between altitudes of 80 m and 400 m, where giant ferns, a flowering Hibiscus plant and native figs dominate (2).

Like other flycatchers, the Tahiti monarch has a diet of insects, which get plucked from the leaves and branches of the forest canopy and undergrowth (2). They defend areas of a few hectares, identifying themselves and their whereabouts with their melodic singing, and will move from tree to tree within the territory, occasionally emitting an alarm call (4). Between October and February one egg is laid in a cup-shaped nest made of moss and decorated with cobwebs. The egg is incubated for 15 – 17 days, and three weeks after hatching the young will fledge (2).

The Tahiti monarch used to be common throughout the island, but during the last century populations underwent a dramatic decrease, and now number less than 50, restricted to a few valleys. These perilous declines have largely been the result of the accidental introduction of the black rat (Rattus rattus) to the island, which prey on the eggs and chicks. However, two introduced birds, the Indian mynah and red-vented bulbul, also pose a significant threat to the monarch's survival. It is thought that the Indian mynah, which was introduced to control wasps, preys on eggs and chicks, whereas the red-vented bulbul competes with the monarch for nest sites and territories (5).

Introduced plants, as well as animals, are also having a negative impact on the Tahiti monarch in some areas. A dense, invasive shrub, Miconia calvescens, was introduced in 1937, and is changing the composition of the forests (2), and presumably altering the areas where the Tahiti monarch likes to nest and feed, such as in Mont Marau, where a population was found in 1980 and is now extinct (6). Four other Pomarea flycatcher species have already become extinct, which highlights the susceptibility of monarch birds to such threats (1). Additionally, as this species is restricted to a very small area, it is very vulnerable to any chance events, such as hurricanes, which could rapidly affect all the individuals in a population.

In 1997, the total population was only 27 individuals. Since then, a conservation programme was implemented, and intensive surveys revealed the population had increased to 40 to 45 birds in 2004 (2) (3). The recovery plan is largely focused on the control of the black rat. During each breeding season, a rat-baiting programme takes place on accessible Tahiti monarch territories (12 territories in 2006); the remainder live in remote areas that are extremely difficult to access. Trees which hold Tahiti monarch nests are fitted with metal rings to protect the nests from climbing rats, and since 2001 the population has been stable or very slowly increasing, and old territories are being reoccupied (6).

Further conservation measures that are planned include improving the forest habitat, by removing invasive plants and trees, and encouraging the growth of native species in which the monarch likes to nest (2). It is likely that control of the introduced mynah and bulbul would also be beneficial to the Tahiti monarch. It is possible that the some of the surviving birds may be taken into captivity, to hopefully breed, and then released back into the wild once a suitable site has been identified, and the habitat has been restored (2).

For further information on this species see Birdlife International:
http://www.birdlife.org/datazone/ebas/index.html?action=SpcHTMDetails.asp&sid=6077&m=0

Authenticated (30/07/07) by Dr Philippe Raust, Société d'Ornithologie de la Polynésie. 
http://www.manu.pf/E_index.html