Talaud black birdwing  (Troides dohertyi)

As its common name suggests, the male of this large tropical butterfly is almost entirely black on its upperside, and as such, is the darkest of all Troides birdwings (3). The underside of the hindwing does, however, bear the golden markings typical of Troides species, and a very few males have faint suggestions of gold colouration on the upper surface of their hindwing, but this is rare. Females have a restricted area of yellow markings on their hindwings, and obscure whitish to tan stripes on their forewings (4). The Talaud black birdwing is regarded by some as a subspecies of Troides rhadamanthus, but is separated by others on the basis of adult colour difference (5).

Confined to the islands of Talaud and the nearby island of Sangihe, Indonesia, between Sulawesi and the Philippines (6).

Inhabits lowland forest and coastal areas (3) (7).

Little has been documented on the biology of this species, but there are certain biological characteristics known to be common to most, if not all, birdwing butterflies. The adults of all Troides species feed on the nectar of flowers, and the larvae on the leaves of Aristolochia and Pararistolochia plants (both in the family Aristolochiaceae) (8). The eggs are normally laid on these plants, and once the caterpillars hatch, they voraciously munch through the leaves around them. Feeding upon these plants also serves as a defensive mechanism, as they contain certain chemicals that make the caterpillars toxic and therefore unpalatable to most predators (9). The caterpillars eventually pupate and undergo metamorphosis into adult butterflies, and may even manage to maintain this toxic acid in their tissues into adulthood (9). Troides birdwings typically pupate on the twigs or stems of plants close to the larval food plant or on the food plant itself (4).

The principal threats to Troides butterflies are increasing human populations and deforestation. Over-collection from the wild for the international market may also have some impact (8). Although still relatively common (6), the Talaud black birdwing is threatened by the large human population in its coastal range (3). The islands are still volcanically active and most of the human ‘development' therefore takes place in the coastal regions where this butterfly lives (3).

Its listing on Appendix II of the Convention on International Trade in Endangered Species (CITES) helps protect this butterfly from excessive trade to international collectors (2), and therefore over-collection from the wild. There are a couple of reserves within the Talaud black birdwing's range, but these are actually hunting reserves rather than true nature or wildlife reserves. Nevertheless, they may provide some protection to this butterfly by preserving crucial areas of habitat that are protected from logging or other land development (3).

Authenticated (05/08/08) by John Tennent, Scientific Associate, Department of Entomology, The Natural History Museum, London.