This large, unique species is one of the most threatened bird species of Southeast Asia. It is heavily targeted by hunters and illegally traded, especially out of Indonesia. Its solid casque is highly prized (3 - 5 times as much as ivory!) and illegally traded in the region and online, China being the biggest buyer, with Thailand and Laos also involved. The casques are carved for decorations.
The trade network is largely managed by organised crime which also trades other high-value wildlife such as Sumatran Tiger and Sunda Pangolin. The hunting pressure is enormous: in West Kalimantan alone, around 500 Helmeted hornbills were killed per month in 2013, resulting in an annual loss of 6,000 individuals.
This insane carnage is made even more devastating because Helmeted hornbills have a very low reproduction rate. The monogamous pairs produce a single chick every other year, as fledged chicks stay with the parents for at least six months.
The pairs nest in natural cavities (mostly large, old trees of the Dipterocarpaceae family). The female is sealed inside the nest chamber until the chick is fully fledged, which may take over 160 days. During this time, she is moulting and dependent on the male feeding herself and the chick. Killing the male will thus also kill the female and the chick.
On top of the poaching comes forest loss, which has reached around 29% within the species' range across just three generations (31.2 years). Forest loss in the regional lowlands has been extremely rapid, and all remaining stands of valuable timber (including those inside protected areas) are being deliberately targeted. Moreover, logging creates access to ever more primary lowland forest, exposing virtually the entire population of this critically endangered species to poachers. Its lowland range is particularly prone to conversion to oil palm and logging, presenting a huge threat to the limited number of trees with suitable nest sites.