In the verdant rainforests of the Philippines' islands of Negros and Panay, one may encounter the striking Walden's hornbill, known locally as dulungan. This critically endangered bird is a large, mostly black avian with a cream-colored tail featuring a black terminal band. The male is adorned with a rufous head, a vibrant yellow pouch, and yellow ocular skin, while the female boasts a black neck and head with blue and yellow around the eye and on the chin. Both sexes have an orange casque and a distinctively wrinkled lower bill.
To identify the Walden's hornbill, look for its large size and the pale coloration of its bill, which sets it apart from the Visayan hornbill, the only other hornbill within its range. The male's rufous head and yellow facial skin, along with the female's black head and blue facial skin, are key distinguishing features. Observers should also note the bird's throaty chuckle, a three-noted call that resonates through the forest.
Walden's hornbill makes its home in closed-canopy forests, sometimes venturing into logged areas or perching on isolated trees in clearings. It thrives at altitudes ranging from 400 to 1,200 meters on Panay and 350 to 950 meters on Negros, favoring regions rich in fruit-bearing trees for sustenance and large trees for nesting.
These hornbills are known to form small, noisy flocks and are primarily frugivorous, feasting on figs and other fruits found in the canopy. They may engage in local nomadic movements in search of food. Walden's hornbills are cavity nesters, utilizing natural or carved-out hollows in tree trunks for their nests. They reproduce slowly, and the scarcity of suitable nesting sites is a significant challenge for their survival.
The Walden's hornbill's vocal repertoire includes a distinctive three-noted throaty chuckle, a sound that is emblematic of its presence in the forest.
These hornbills are cavity nesters, and due to their slow reproductive rate, they are particularly vulnerable to habitat loss and poaching. Nest boxes have been installed in some reserves to mitigate the loss of natural nesting sites.
An omnivorous bird, the Walden's hornbill primarily consumes fruits, particularly figs, but also takes some animal matter to its nests.
The Walden's hornbill is classified as Critically Endangered, with a population estimated at less than 160 individuals on Negros, where it may be functionally extinct, and 600-700 pairs on Panay. The species faces threats from habitat destruction due to logging and land conversion, as well as hunting and capture for the illegal wildlife trade. Conservation efforts include nest guarding programs, installation of nest boxes, and captive breeding initiatives, which have shown some success in bolstering the population.