The Hooded pitohui (Pitohui dichrous ) is a species of bird in the genus Pitohui found in New Guinea. This is one of the few known poisonous birds, containing a range of batrachotoxin compounds in its skin, feathers, and other tissues. The toxic nature of this bird is well known to local hunters, who avoid it. It is one of the most poisonous species of pitohui, but the toxicity of individual birds can vary geographically.
The Hooded pitohui is 22 to 23 cm (8.7–9.1 in) long and weighs 65–76 g (2.3–2.7 oz). The adult has a black upperwing, head, chin, throat, and upper breast and a black tail. The rest of the plumage is a rufous chestnut. The bill and legs are black, and the irises are either reddish brown, dark brown, or black. Both sexes look alike. Juvenile birds look like adults, except that the rectrices of the tail and remiges of the wing are tinged with brown.
Hooded pitohuis can be found only in the islands of New Guinea. They occur across the main island, and also on the nearby island of Yapen. These birds live in rainforests, forest edge habitats and secondary growth, and sometimes mangrove forests. They are most commonly found in hills and low mountains.
Hooded pitohuis are social birds that live in family groups. They feed at all levels of the forest, from the forest floor to the canopy, and frequently join and even lead mixed-species foraging flocks. The toxins contained in the feathers of these exotic birds are thought to be derived from their diet, in a process known as Kleptotoxicism, and may function both to deter predators and to protect the bird from parasites. Hooded pitohuis are quite vocal and make a variety of calls, mostly forms of whistles. Their song is a variable collection of three to seven whistles, which can slur up or down with hesitant pauses in between. Usually, the song begins with two similar notes followed by an upslur. They also make a ‘tuk tuk w’oh tuw’uow’ call, two whistled ‘woiy, woiy’ notes, two downslurred whistled ‘tiuw tow’ notes, and three whistles ‘hui-whui-whooee’, which increase in volume.
In 1990 scientists preparing the skins of the Hooded pitohui for museum collections experienced numbness and burning when handling them. It was reported in 1992 that this species and some other pitohuis contained a neurotoxin called homobatrachotoxin, a derivative of batrachotoxin, in their tissues. This made them the first documented poisonous birds, other than some reports of coturnism caused by consuming quail (although toxicity in quails is unusual), and the first bird discovered with toxins in the skin. The same toxin had previously been found only in Colombian poison dart frogs from the genus Phyllobates (family Dendrobatidae)..
Bioassays of their tissue found that the skins and feathers were the most toxic, the heart and liver less toxic, and the skeletal muscles the least toxic parts of the birds. Of the feathers, the toxin is most prevalent in those covering the breast and belly.
The poisonous pitohuis, including the Hooded pitohui sequester toxic compounds from their diet.
Hooded pitohuis are omnivorous birds. Their diet is dominated by fruit, particularly figs, grass seeds, some insects and other invertebrates, and possibly small vertebrates. Among favored invertebrates are beetles, spiders, earwigs, bugs, flies, caterpillars, and ants.
Little is known about the breeding habits of Hooded pitohuis due to the difficulties of studying the species high in the canopy of New Guinea. Nests with eggs of these birds have been found from October through to February. The nest that has been described was 2 m (7 ft) off the ground; it is a cup of vine tendrils, lined with finer vines and suspended on thin branches. The clutch is 1-2 eggs, which are creamy or pinkish with brown to black spots and blotches and faint grey patches. The incubation period is not known, but Hooded pitohuis are thought to be cooperative breeders, as more than two birds in a group have been observed defending the nest from intruders and feeding the young. Young birds, which are covered in white down as nestlings before developing their adult plumage, have been observed being fed acorn-shaped red berries and insects. Young birds will make a threat display when approached in the nest, rising up and erecting their head feathers. As chicks develop directly into adult plumage, it has been suggested that this display may be signaling its identity as a toxic species, even though young birds have not developed toxicity at that age.
Hooded pitohuis don’t face any major threats at present.
According to IUCN Red List, the Hooded pitohui is locally common and widespread throughout its range but no overall population estimate is available. Currently, this species is classified as Least Concern (LC) on the IUCN Red List and its numbers today remain stable.
