Pemba green-pigeon  (Treron pembaensis)

The Pemba green-pigeon is a small, stocky pigeon found only on a single island in the Indian Ocean. The head, neck, breast and underparts are slate-grey, tinged with green, and prominent dark mauve patches sit on each shoulder. The rest of the upperparts are dull olive-green, which contrasts with its bright orangey-yellow feet and red bill tipped with greyish-white. The eyes are bluish-grey, with an outer ring of bare red skin (2) (3). The fluty whistles and trills of the green-pigeon's call are broken by throaty grunts and growls. It can also be heard clucking quietly or rapidly snapping and clicking its bill (2).

Occurs on Pemba Island, off the north coast of Tanzania (2)

The Pemba green-pigeon inhabits forests, as well as modified environments such as cultivated areas, parks and well-wooded gardens (2) (3). It can also be found on coral islets adjacent to wooded coasts (2).

The Pemba green-pigeon spends most of its time high in the trees, where it feeds in the canopy on a wide variety of fruit and only descends to the ground to take fallen fruit. It is known to consume figs and mangoes and is particularly fond of the young fruits of the betal palm Areca Catechu (2) (4). Pemba green-pigeons are found in pairs or small flocks, and despite a history of hunting reportedly making this pigeon shy, it visits fruiting trees in urban areas and villages (2).

Pemba green-pigeons may also nest close to human habitation, in gardens and plantations. Breeding is believed to occur primarily from October to February, when a pair of pernickety pigeons will build two or three flimsy, twig nests before finally selecting one in which to lay their eggs. The chosen nest, situated in a thick tangle of branches and vines, will house the one or two glossy white eggs (2). Unfortunately, these fragile nests are often destroyed by gusts of wind (3).

The restricted range of the Pemba green-pigeon makes it particularly susceptible to the impacts of the numerous human activities that are reducing the amount of suitable habitat for the pigeon. Pemba green-pigeons can inhabit clove plantations, but a drop in world clove prices has led to their conversion to the unsuitable habitat of rice and cassava farms. Natural forests of Pemba Island are also being converted to rubber plantations, or exploited for building materials and fuelwood (5).

Pemba green-pigeons are found in two forest reserves, Ngezi and Msitu Mkuu, which hopefully offers some protection although, undoubtedly, illegal and damaging activities still occur in these areas. The increased enforcement of laws regarding the forest reserves, and further research into the requirements of this species, are both measures that have been proposed to ensure that the Pemba green-pigeon climbs no higher in the Red List of threatened species (5).

For further information on the Pemba green-pigeon see:

• BirdLife International:
  www.birdlife.org/datazone/ebas/index.html?action=SpcHTMDetails.asp&sid=2646&m=0

Authenticated (04/06/08) by Jonathan S. Walker, Ph.D., Director, Columbidae Conservation.
http://www.columbidae.org.uk