Mindanao broadbill  (Eurylaimus steerii)

The Mindanao broadbill is classified as Vulnerable (VU) on the IUCN Red List (1).

The Mindanao broadbill (Eurylaimus steerii) is a brightly coloured forest bird, known for the large, elaborate nests it constructs. The most noticeable feature of the Mindanao broadbill is the sky-blue, fleshy, wrinkled fold of skin, known as wattle, which surrounds each eye (2) (4).

The male Mindanao broadbill has a dark grey upper back, while the lower back and tail are reddish-brown. The rump and uppertail coverts have a purple wash. The wings are black, with a conspicuous white and yellow band. The underparts are lilac, becoming yellowish-white on the lower belly (2). 

The forehead and crown of the Mindanao broadbill are maroon-purple, the face and throat are black, and a white collar encircles the neck. The eye colour ranges from green to blue, and the bill, legs and feet are light blue (2).

Female Mindanao broadbills are similar in appearance to males, except they have a bright white breast and belly (2) (3) (4). The juvenile Mindanao broadbill has a duller appearance (4), with a dark grey crown, a white throat that blends into black, and an olive-washed back (2) (3). It also has a yellow eye wattle (2), brown eyes and a black bill (3).

The call of the Mindanao broadbill is a melancholic whistle (3). It also produces a loud whirring noise with its wings during short flights, and a loud snapping noise with its bill while perched (3).

The Mindanao broadbill is endemic to the southern Philippines. It is present on the islands of Mindanao, Siargao, Dinagat and Basilan, and the islets of Malamaui and Poneas (2) (4).

The Mindanao broadbill inhabits primary and secondary forest. It is occasionally also found in shrublands and mangroves. The Mindanao broadbill is usually found well below 1,000 metres, but occasionally occurs up to 1,200 metres (2) (4).

Although the Mindanao broadbill has been observed in flocks with other bird species, the Mindanao broadbill is often solitary, and can be seen sitting still on an exposed perch (3).

Like most other broadbills, the Mindanao broadbill is insectivorous, but there are no details on the species it preys upon. It forages singly, in pairs, or in small flocks of up to six birds, in the lower and middle levels of the forest. It primarily plucks its insect prey from vegetation, but it is also extremely good at catching prey while in flight. It usually makes a short flight to catch prey, and then returns to the same or a nearby perch, but has also been observed jumping from one branch to another in pursuit of prey. The insect prey is sometimes beaten against a branch before being swallowed (2) (5). 

Like those of other broadbills, the nest of the Mindanao broadbill is a large, elaborate and pear-shaped structure. The bulk of the nest hangs from a thin rope of plant fibres and grasses, with a large entrance near the top, and an untidy tail of plant material trailing below. Made of any available material, such as twigs, leaves, roots, lichen and moss, the nest usually hangs from low branches or plants close to water (5) (6) (7). The breeding season of the Mindanao broadbill is thought to take place between April and June (2), during which time the female will lay two to four eggs (5).

Deforestation is the greatest threat to the Mindanao broadbill, which is sensitive to habitat disturbance. In 1988, only an estimated 29 percent of the forest cover remained on Mindanao, most of which was above elevations of 1,000 metres. The extensive lowland deforestation continues at a fast pace, largely due to logging and mining. Illegal logging, substitution of the forests’ trees with exotic trees for paper production, and fires also contribute to the loss of the Mindanao broadbill’s habitat (2) (4).

The Mindanao broadbill occurs in Mount Apo Natural Park and on Siargao Island, which is a protected area. It has also been recorded in Mount Hilong-hilong Watershed Reserve, the Basilan Natural Biotic Area and Mount Matutum Forest Reserve, but as these records are from before 1980, it is not clear whether the Mindanao broadbill still occurs there (4).

Ensuring that these protected areas are adequately protected and managed is vital for the survival of the Mindanao broadbill, and other conservation measures have also been suggested. One such measure is the identification and surveillance of the lowland forest that remains, to establish the Mindanao broadbill’s present distribution and status. Sites that support key populations should then be proposed for protection (4).

Learn more about conservation in the Philippines:

• Conservation International:
  http://www.conservation.org/explore/asia-pacific/philippines
• Philippine Endemic Species Conservation Project:
  http://www.pescp.org/
• Haribon Foundation:
  http://www.haribon.org/

Discover more about the Mindanao broadbill and other birds:

• BirdLife International - Mindanao broadbilll:
  http://www.birdlife.org/datazone/speciesfactsheet.php?id=4033