which were considered absolutely certain (Collar 1998).
The species is classified as Endangered (under criterion
C1) because it has a small population, estimated to
number 1,000–2,499 individuals, which is believed
to be declining at a rate exceeding 20% in five years/two
generations (BirdLife International 2000, 2001). Little
is known of the ecology and of the behaviour of the
species (Collar et al. 1999). Its call was hitherto
unknown (Kennedy et al. 2000). Independently of each
other, we observed a pair of Isabela Orioles in Ambabok,
Disulap, municipality of San Mariano, Isabela province
on 27 and 29 March 2003 (RH) and 25 and 26 May 2003
(MvW). In April 2004, one Isabela Oriole was captured
here using a mist-net and released after documentation.
the morning of 27 March, RH was birding close to the
former settlement of Ambabok when he heard