The paradise kingfishers (genus Tanysiptera) are a group of tree kingfishers endemic to New Guinea — with the exception of two species also present in the Moluccas and Queensland.
The genus was erected by the Irish zoologist Nicholas Aylward Vigors in 1825. The type species is the common paradise kingfisher. The name Tanysiptera is from classical Greek tanusipteros meaning "long-feathered". The birds in the genus have distinctive long tail streamers.
Habitat and distribution
The centre of paradise kingfishers is New Guinea: Several species occur on this 786,000 km2 large island. In addition, there are several island endemisms that occur on islands of the Moluccas and the Louisiade Archipelago. Most paradise kingfishers are resident birds. The buff-breasted paradise kingfisher, which also occurs in the extreme northeast of Australia, moves to New Guinea in the winter half-year. The common paradise kingfisher has the biggest spread among the paradisiacis birds. It occurs in 15 subspecies on New Guinea and islands of the Moluccas and the Louisiade Archipelago. On New Guinea itself, several subspecies of the common paradise kingfisher live there. The remaining subspecies are limited in their spread to individual islands or island groups. The red-breasted paradise kingfisher and the brown-headed paradise kingfisher only occur on New Guinea. The little paradise kingfisher has its residence on the Aru Islands Regency and in the outermost south of New Guinea. It is assumed that the little paradise kingfisher comes from the common paradise kingfisher and developed on the Aru Islands Regency to an independent species. From this place it settled in New Guinea, where today the distribution area of the two species overlaps. These two species do not produce any natural hybrids. The Kofiau paradise kingfisher is also closely related to the common paradise kingfisher, which only occurs on Kofiau.
Description
Most species of paradise kingfishers are commonly observed in their natural habitat within the interior forests of New Guinea. However, the species itself has been known to be attracted to rivers and coasts and they demonstrate an ability to fly over large bodies of water, which is observed in the Buff-Breasted paradise kingfisher that migrates to Queensland, Australia during breeding season. An aspect found within the species is the syndactyly in the feet, where the third and fourth toe of the bird is fused together. There are several arguments to what benefits syndactyly proposes, one is that syndactyl feet may be likened to more strength for perching on branches. This may aid the bird when having to hunt for prey within the rainforest environment in which they are located. Others claim that because paradise-kingfishers nest in termite mounds, this aids the birds in digging out hole-nests for their young. Finally, there are some arguments that syndactyly has no benefit to the bird at all. The plumage of juvenile paradise kingfishers differs from that of an adult bird until they undergo a partial moulting phase where only the flight feathers are retained and then it looks similar to that of a full-grown adult. In buff-breasted paradise-kingfishers, adults demonstrate colourful plumage, bright beaks and sport long tails, half the size of the birds. Immature birds on the other hand, have duller plumage, black coloured bills and missing the long tail found in adult birds.
Most paradise-kingfishers are extremely territorial, with most birds living in territorial pairs but choosing to forage alone. Some studies also claim that this territoriality is attributed to the defence of resources within the area. Upon observation of the breeding habits of the buff-breasted paradise-kingfisher, it found that they to actively defend their territory at the vocalisation of other intruder birds and chases involving two to four males were common, to the extent of males causing damage on each other such as broken wings. Paradise kingfishers are classified as hole-nesters and use their webbed feet to excavate nest holes in termite mounds. Most species chose arboreal termite mounds located on the sides of trees about 3–4.5m from the ground and those that are still actively inhabited by termites. This is because studies show that live termitariums are stronger when inhabited and become fragile after the insects leave, making them more susceptible to predators.