White collared kingfisher
Long tailed shrike
Black naped oriole
Scaley breasted munia
Olive backed sunbird
White breasted wood swallow
Yellow vented bulbul
I also took a few landscape shots.
When I reached the Angono Petroglyphs site, I tried to look for some objects of interest after a short rest. On the ground, I saw something that looks like the tail of either a skink or a snake. It seems to be the former, but I'm not really sure. It's probably bitten off by the owl.
Then, together with the officer-in-charge of the site, we saw the owl.
A few minutes later, thinking that I've seen enough that day, I decided to leave.
I managed to compile this list of birds during the hike.
Eurasian tree sparrow - a lot
Yellow vented bulbul - at least 4
Olive backed sunbird - at least 5
Pied thriller - 1
Philippine eagle-owl - 1
Black naped oriole - 4
White breasted wood swallow - at least 6
White collared kingfisher - 2 seen, at least 2 heard only
Philippine bush warbler - 1
Long tailed shrike - 2
Swiftlet - 2
Striated grassbird - at least 3
Scaley breasted munia - 2
Gray backed tailorbird - 1 seen, 1 heard
Philippine coucal - at least 2 heard only
Golden bellied gerygone - at least 3 heard only