Rufous Hornbill or Philippine Hornbill (Buceros hydrocorax) or Kalaw
The Rufous Hornbill (Buceros hydrocorax), also known as Philippine Hornbill and, locally, as Kalaw (pronounced kah-lau) is a large species of hornbill endemic to the Philippines, where it occurs in primary, mature secondary and disturbed forests on 11 islands: Luzon and Marinduque (race hydrocorax), Samar, Leyte, Bohol, Panaon, Biliran, Calicoan and Buad (race semigaleatus), Dinagat, Siargao, Mindanao (plus Balut, Bucas, and Talicud) and Basilan (race mindanensis).

It is still common locally, notably in the Sierra Madre of Luzon, but continues to suffer from substantial hunting pressure and widespread loss of habitat.
The bill of the nominate subspecies is all-red, while the bills of the subspecies semigaleatus and mindanensis are pale yellow on the distal half.
Breeding / Nesting
As with other hornbills, females seal themselves within the nest cavity, where they lay the clutch and remain with the growing young for most or all of the nesting period.
In some species, the male helps with the sealing process from outside the nest cavity.
The nestlings and female are fed by the male through a narrow vertical slit in the sealed nest opening.

References
- BirdLife International (2008).. In: IUCN 2010.1. IUCN Red List of Threatened Species.. .
- Witmer, Mark (1993). Cooperative Breeding by Rufous Hornbills on Mindanao Island, Philippines”. The Auk 110 (4): 933–936.