Henderson fruit-dove  (Ptilinopus insularis)

This colourful little pigeon is found only on a remote, uninhabited island in the South Pacific Ocean. Its forehead and crown are a bright crimson, narrowly bordered by golden-yellow. The head, neck, upper back and chest are a silvery-grey tinged with green, whilst the rest of the body is dark olive-green with a yellowish-green belly. The wing feathers are edged in yellow, and it has a yellow-green bill and red feet (2) (3). Juveniles can be identified by the lack of a crimson crown (2). Like other pigeons, the Henderson fruit-dove has a coarse cooing call (3).

The Henderson fruit-dove is found only on Henderson Island, one of the four Pitcairn Islands (1). Henderson Island is a small uninhabited, raised-reef island in the south-central Pacific Ocean, with no major landmass within a 5,000 kilometres radius (4).

Inhabits forests with dense understorey, generally in the interior of the island (2).

As suggested by its name, the Henderson fruit-dove is a frugivore and feeds on 19 species of fruit, which is nearly all the suitable fruit growing on Henderson island. It eats the fruit of Procis pedunculata, a member of the nettle family, most frequently (5). By eating the fruits of Henderson Island, this dove plays an important role in seed dispersal on the island (6).

The Henderson fruit-dove appears to be a territorial bird, defending an area containing fruit plants that they can eat when the fruit becomes seasonally available. There is almost no freshwater on Henderson Island, making life very difficult for the animals which live there, but the fruit-dove overcomes this problem by eating fruit with a very high water content (1).

There is not much information on the breeding behaviour of the Henderson fruit-dove, but it is thought that the breeding season is at the beginning of the year and that the female lays a single egg (1).

As Henderson Island is uninhabited, the Henderson fruit-dove is not threatened by the habitat degradation that frequently threatens other island species. However, because the Henderson fruit-dove is restricted to only one small island, it is very vulnerable to the accidental introduction of a pest species or disease, via unauthorized boats landing on the island. The Polynesian rat Rattus exulans has been introduced to the island without a negative affect on the Henderson fruit-dove, but there is concern that the introduction of other Rattus species, such as the black rat, could have devastating consequences.

Henderson Island was designated a World Heritage Site in 1988. Whilst the island is currently relatively undisturbed, a management plan has been drawn up with objectives such as preventing the introduction of exotic species, ensuring visitors do not damage the island in any way, and the introduction of a significant fee for stopping at Henderson (4). These measures will help ensure that the future of the Henderson fruit-dove is secure.

For further information on the Henderson fruit-dove see:

• Birdlife International:
  www.birdlife.org/datazone/ebas/index.html?action=SpcHTMDetails.asp&sid=2688&m=0

Authenticated (08/05/08) by Dr Michael Brooke. Department of Zoology, University of Cambridge.