Philippine Eagle and other Avian Species Survey at Mt Apo, Davao City

SYNOPSIS

The remaining Forest in the areas of Alikoson-Macabol Mountains has been known to accommodate a pair of Philippine Eagle since 1986. A total of 4 known nesting trees has been monitored within the area. Since its discovery, the pair has been regularly producing offspring every breeding season, up until last 2014 -2015 breeding season. We suspect that the eagle pair has been nesting on a new nest tree since 2015. The objective of this year’s monitoring is to find that new nesting tree.
In this 1-day activity, a team was sent to conduct preliminary survey and reconnaissance of possible observation posts for future Philippine Eagle monitoring.

METHODOLOGY

Philippine Eagle Post Monitoring Survey

Last June 8, the team visited an observation post (OP) just adjacent from Sitio Falcata (see figure 1, Map). This area was occupied before during 2013-2015 Philippine eagle monitoring. As compared to rigorous hikes on the other day, going to the post observation site was relaxing, where the team only spend 30 minutes in walking. Equip with monitoring equipment the team scans the wide and overlooking area of the OP for any passing raptors seen during the activity. The team also discussed as to which sites should be visited on the next 10-day expedition.
For post monitoring and observations, the team used “look-and-see” method (Bibby, et al., 1998) accompanied with the following devices; three pieces of binoculars (2 Nikon Monarch 8x42, and 1 Swarovski 8x30 magnifications), one fieldscope (Swarovski optik) and a zoom-lensed camera (Canon EOS 800D head and Tamron 150-600mm lens) in recording observations for flying raptors and other birds. For other raptors and birds, the team listed each species they encountered during the fieldwork. All documented birds were identified using “A guide to the birds of the Philippines” book (Kennedy, et al., 2000) and were updated down to their species level using the “Checklist of Birds of the Philippines 2019” (Jensen, et al., 2019).

RESULTS

From our observation post, the team overlooked the forested areas of Masawang (previous nesting site in Alikoson forest) going to Sitio Kiandong, and Sitio Lais forested areas. During the whole day activity last June 8, the team did not detect any sightings of Philippine Eagle. Though based on our random interviews, the locals from Sitio Taupan and Sitio Tribal has reportedly seen sightings of Philippine Eagle recently.
A total of 8 hours was spent for observations during the activity, last June 8, 2022. Though there were no sightings of Philippine Eagle during the one-day survey, the team manage to detect four forest raptors. Namely the Philippine Serpent Eagle (Spilornis holospilus), Philippine Honey buzzard (Pernis steerei), Brahminy Kite (Haliastur indus), and Pinsker's Hawk-eagle (Nisaetus pinskeri), and 75 % of these detected raptors were endemic.
All and all the team documented 42 bird species belonging to 26 families were recorded namely Phasianidae, Rallidae, Accipitridae, Columbidae. Cuculidae, Apodidae, Trogonidae, Meropidae, Bucerotidae, Megalaimidae, Picidae, Psittaculidae, Artamidae, Campephagidae, Pachycephalidae, Corvidae, Paridae. Pycnonotidae, Cettiidae, Locustellidae, Zosteropidae, Sittidae, Sturnidae, Muscicapidae, Dicaeidae, and Nectariniidae (Annex).
Out of 42 species, 38% (16 species) were resident, and 61% (26 species) were endemic species (Annex). Part from the species listed during the activity includes the IUCN “Endangered” species Pinsker's Hawk-Eagle (Nisaetus pinskeri), the “Vulnerable” species Mindanao Rufous Hornbill (Buceros hydrocorax mindanensis), and the “Near Threatened” species namely the Writhed Hornbill (Rhabdotorrhinus leucocephalus) and the Lina's Sunbird (Aethopyga linaraborae) (IUCN, 2019). In such short opportunistic avifaunal survey, the team infers that the site holds plenty species of birds that where unrecorded, and highly recommends a further elaborative study. In addition, with rare and threatened species recorded, the site isan important habitat serving as important haven for this avifaunal species.

Table 1. List of Birds during the activity

Family Common Name Uvo Manuvu Name Scientific Name

Phasianidae Red Junglefowl Manok Gallus gallus
Rallidae Plain Bush-hen Tung-giyok Amaurornis olivacea
Accipitridae Brahminy Kite Monou' Haliastur indus
Accipitridae Pinsker's Hawk-Eagle Baog ta lutang' Nisaetus pinskeri
Accipitridae Philippine Serpent Eagle Kulihi Spilornins holospilus
Accipitridae Philippine Honey Buzzard Maninigbas Pernis steerei
Columbidae White-eared brown dove Alimokon Phapitreron leucotis
Cuculidae Philippine Coucal Kokok Centropus viridis
Cuculidae Black-faced coucal Lambugan Centropus melanops
Cuculidae Rusty-breasted Cuckoo Tiduding Cacomantis sepulcralis
Apodidae Ridgetop Swiftlet Sayaw Collocalia isonota
Trogonidae Philippine Trogon Ak-ak Harpactes ardens
Meropidae Blue-tailed Bee-eater Puloy-puloy Merops amercanus
Bucerotidae Rufous Hornbill Kalyawa Buceros hydrocorax mindanensis
Bucerotidae Mindanao Tarictic Hornbill Tugkos Penelopides affinis
Bucerotidae Writhed Hornbill Kayamutan Rhabdotorrhinus leucocephalus
Megalaimidae Coppersmith Barbet Pokpok Psilopogon haemacephalus
Picidae Philippine Pygmy Woodpecker Yungipicus maculatus
Psittaculidae Blue-crowned Racket-tail Kullet Prioniturus discurus
Artamidae White-breasted Woodswallow It-it Artamus leucorynchus
Campephagidae Scarlet Minivet Kuryot Pericrocotus speciosus
Campephagidae Pied Triller Sagksak Lalage nigra
Pachycephalidae Yellow-bellied Whistler Broing Pachycephala philippinensis
Corvidae Large-billed Crow Uwak Corvus macrorhynchos
Paridae Elegant Tit Kalimot-limot Pardaliparus elegans
Pycnonotidae Philippine Bulbul Bayako Hypsipetes philippinus
Pycnonotidae Yellow-vented Bulbul Ullou Pycnonotus goiavier
Cettiidae Mountain Tailorbird Kalinsawi Phyllergates cucullatus
Locustellidae Striated Grassbird Chakokok Megalurus palustris
Zosteropidae Warbling White-eye Katiyo Zosterops japonicus
Sittidae Sulphur-billed Nuthatch Padidit Sitta oenochlamys
Sturnidae Coleto Sal-ing Sarcops calvus
Muscicapidae Little Pied Flycatcher Tamsi Ficedula westermanni
Alcedinidae White-throated Kingfisher Tingkarol Halcyon smyrnensis
Dicaeidae Red-keeled Flowerpecker Tamsi Dicaeum australe
Dicaeidae Orange-bellied Flowerpecker Tamsi Dicaeum trigonostigma
Dicaeidae Buzzing Flowerpecker Tamsi Dicaeum hypoleucum
Dicaeidae Pygmy Flowerpecker Tamsi Dicaeum pygmaeum
Dicaeidae Fire-breasted Flowerpecker Dicaeum ignipectus
Nectariniidae Lina's Sunbird Tamsi Aethopyga linaraborae