Animalia > Chordata > Aves > Bucerotiformes > Bucerotidae > Aceros > Aceros waldeni

Aceros waldeni (Walden's Hornbill; Rufous-headed Hornbill)

Wikipedia Abstract

The Walden's hornbill (Aceros waldeni) locally called dulungan, also known as the Visayan wrinkled hornbill, rufous-headed hornbill or writhed-billed hornbill, is a critically endangered species of hornbill living in the rainforests on the islands of Negros and Panay in the Philippines. It is closely related to the writhed hornbill, but can be recognized by the yellow throat and ocular skin in the male, and the blue throat and ocular skin in the female (both throat and ocular skin are deep orange or red in both sexes of the writhed hornbill). Its binomial name commemorates the Scottish ornithologist Viscount Walden.
View Wikipedia Record: Aceros waldeni

Endangered Species

Status: Critically Endangered
View IUCN Record: Aceros waldeni

EDGE Analysis

This colourful and distinctive bird is the World’s second most endangered hornbill. Like most hornbills it possesses a bony ‘casque’, which protrudes from the top of its bill. In the Rufous-headed Hornbill this structure is red-orange and has a wrinkled appearance. Originally found on the three islands of Negros, Panay and Guimaras, it is now locally extinct from the latter due to severe deforestation. Hunting and nest poaching confound this.
Uniqueness Scale: Similiar (0) 
 Unique (100)
Uniqueness & Vulnerability Scale: Similiar & Secure (0) 
 Unique & Vulnerable (100)
ED Score: 11.1527
EDGE Score: 5.27014
View EDGE Record: Aceros waldeni


Adult Weight [1]  2.09 lbs (950 g)
Female Weight [1]  1.65 lbs (750 g)
Male Weight [1]  2.54 lbs (1.15 kg)
Weight Dimorphism [1]  53.3 %
Diet [2]  Frugivore
Diet - Fruit [2]  100 %
Forages - Canopy [2]  90 %
Forages - Ground [2]  10 %
Clutch Size [3]  2


Name Countries Ecozone Biome Species Report Climate Land
Greater Negros-Panay rain forests Philippines Indo-Malayan Tropical and Subtropical Moist Broadleaf Forests

Important Bird Areas

BirdLife Species Factsheet: View Factsheet
Name Location  IBA Criteria   Website   Climate   Land Use 
Central Panay mountains Philippines A1, A2
Cuernos de Negros Philippines A1
Mount Kanla-on Natural Park Philippines A1, A2
Northwest Panay Peninsula Natural Park Philippines A1, A2
Southwestern Negros Philippines A1, A2

Biodiversity Hotspots

Name Location Endemic Species Website
Philippines Philippines Yes

Prey / Diet

Ficus acamptophylla[4]
Ficus benjamina (weeping fig)[4]
Ficus caulocarpa[4]
Ficus consociata[4]
Ficus crassiramea[4]
Ficus crassiramea subsp. crassiramea[4]
Ficus crassiramea subsp. stupenda[4]
Ficus gasparriniana[4]
Ficus grewiifolia[5]
Ficus pellucidopunctata[4]
Ficus ruginervia[4]
Ficus subcordata[4]
Ficus sundaica[4]
Ficus trichocarpa[4]
Ficus xylophylla[4]
Myristica ceylanica[5]
Platea excelsa[5]
Pometia pinnata (taun tree)[5]
Ternstroemia philippinensis var. megacarpa[5]

Prey / Diet Overlap

Competing SpeciesCommon Prey Count
Acerodon jubatus (golden-capped fruit bat)3
Aceros cassidix (Knobbed Hornbill)2
Aceros corrugatus (Wrinkled Hornbill)7
Aegithina tiphia (Common Iora)1
Alophoixus bres (Grey-cheeked Bulbul)7
Anorrhinus galeritus (Bushy-crested Hornbill)11
Anorrhinus tickelli (Brown Hornbill)2
Anthracoceros albirostris (Oriental Pied Hornbill)2
Anthracoceros malayanus (Black Hornbill)13
Arborophila chloropus (Green-legged Partridge)1
Arctictis binturong (Binturong)4
Arctogalidia trivirgata (Small-toothed Palm Civet)1
Balionycteris maculata (spotted-winged fruit bat)1
Berenicornis comatus (White-crowned Hornbill)4
Buceros bicornis (Great Hornbill)2
Buceros rhinoceros (Rhinoceros Hornbill)10
Callosciurus adamsi (ear-spot squirrel)2
Callosciurus finlaysonii (Finlayson's squirrel)2
Callosciurus nigrovittatus (black-striped squirrel)4
Callosciurus notatus (plantain squirrel)9
Callosciurus prevostii (Prevost's squirrel)11
Chalcophaps indica (Common Emerald Dove)3
Corvus enca (Slender-billed Crow)3
Cynopterus brachyotis (lesser short-nosed fruit bat)3
Cynopterus sphinx (greater short-nosed fruit bat)1
Dicaeum trigonostigma (Orange-bellied Flowerpecker)7
Ducula aenea (Green Imperial Pigeon)2
Ducula bicolor (Pied Imperial Pigeon)3
Ducula poliocephala (Pink-bellied Imperial Pigeon)2
Elephas maximus (Asiatic Elephant)1
Eudynamys scolopaceus (Asian Koel)2
Geokichla interpres (Chestnut-capped Thrush)2
Gracula religiosa (Hill Myna)6
Harpactes diardii (Diard's Trogon)1
Helarctos malayanus (Sun bear)2
Hoolock hoolock hoolock (hoolock gibbon)1
Hylobates agilis (agile gibbon)3
Hylobates lar (white-handed gibbon)5
Hylobates moloch (silvery gibbon)1
Hypsipetes philippinus (Philippine Bulbul)1
Irena puella (Asian Fairy-bluebird)11
Lophura ignita (Crested Fireback)1
Lophura nycthemera (Silver Pheasant)1
Macaca fascicularis (long-tailed macaque)10
Macaca nemestrina (pigtail macaque)3
Macaca nigra (Celebes crested macaque)2
Macaca silenus (liontail macaque)1
Macroglossus minimus (lesser long-tongued fruit bat)1
Martes flavigula (Yellow-throated Marten)1
Megalaima haemacephala (Coppersmith Barbet)2
Muntiacus muntjak (Indian muntjac)1
Nasalis larvatus (proboscis monkey)1
Oriolus chinensis (Black-naped Oriole)2
Oriolus xanthonotus (Dark-throated Oriole)6
Penelopides panini (Tarictic Hornbill)5
Penthetor lucasi (Lucas's short-nosed fruit bat)1
Petaurista petaurista (red giant flying squirrel)1
Phapitreron amethystinus (Amethyst Brown Dove)1
Phapitreron leucotis (White-eared Brown Dove)3
Pongo pygmaeus (orangutan)12
Presbytis potenziani (Mentawai leaf monkey)2
Presbytis rubicunda (red leaf monkey)2
Ptenochirus jagori (greater musky fruit bat)2
Pteropus giganteus (Indian flying fox)1
Pteropus vampyrus (large flying fox)2
Ptilinopus occipitalis (Yellow-breasted Fruit Dove)2
Pycnonotus atriceps (Black-headed Bulbul)2
Pycnonotus goiavier (Yellow-vented Bulbul)4
Pycnonotus plumosus (Olive-winged Bulbul)4
Ratufa affinis (pale giant squirrel)4
Ratufa bicolor (black giant squirrel)5
Rhabdornis mystacalis (Stripe-headed Creeper)1
Rhinoplax vigil (Helmeted Hornbill)9
Rhyticeros undulatus (Wreathed Hornbill)8
Rusa unicolor (sambar)1
Sarcops calvus (Coleto)1
Sundasciurus tenuis (slender squirrel)3
Sus barbatus (bearded pig)1
Sus cebifrons (Visayan warty pig)1
Sus scrofa (wild boar)1
Symphalangus syndactylus (siamang)5
Tamiops rodolphii (Cambodian striped squirrel)1
Trachypithecus obscurus (dusky leaf monkey)1
Treron curvirostra (Thick-billed Green Pigeon)10
Treron vernans (Pink-necked Green Pigeon)2
Turdus obscurus (Eyebrowed Thrush)1
Varanus olivaceus (Gray’s Monitor Lizard)1
Zosterops montanus (Mountain White-eye)1
Zosterops nigrorum (Yellowish White-eye)1
Zosterops palpebrosus (Oriental White-eye)1


Southern Asia;



Attributes / relations provided by
1Wildlife As Canon Sees It
2Hamish Wilman, Jonathan Belmaker, Jennifer Simpson, Carolina de la Rosa, Marcelo M. Rivadeneira, and Walter Jetz. 2014. EltonTraits 1.0: Species-level foraging attributes of the world's birds and mammals. Ecology 95:2027
3Jetz W, Sekercioglu CH, Böhning-Gaese K (2008) The Worldwide Variation in Avian Clutch Size across Species and Space PLoS Biol 6(12): e303. doi:10.1371/journal.pbio.0060303
4"Fig-eating by vertebrate frugivores: a global review", MIKE SHANAHAN, SAMSON SO, STEPHEN G. COMPTON and RICHARD CORLETT, Biol. Rev. (2001), 76, pp. 529–572
5Interactions among Frugivores and Fleshy Fruit Trees in a Philippine Submontane Rainforest, Andreas Hamann and Eberhard Curio, Conservation Biology Volume 13, No. 4, August 1999, Pages 766–773
Ecoregions provided by World Wide Fund For Nature (WWF). WildFinder: Online database of species distributions, ver. 01.06 WWF WildFINDER
Biodiversity Hotspots provided by Critical Ecosystem Partnership Fund
Abstract provided by DBpedia licensed under a Creative Commons License
Weather provided by NOAA METAR Data Access