Observations
of Isabela Oriole Oriolus Isabellae in
the Sierra Madre, Luzon, Philippines, with
Descriptions of the Call

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MERLIJN VAN WEERD
and ROB HUTCHINSON
However,
all observations in which the habitat has been recorded
are from secondary forest, suggesting that this is the species’s
preferred habitat or that it may be rather adaptable to
habitat change. The Isabela Oriole is apparently not now
hunted or collected, so the only plausible causes of its
apparent decline are habitat loss and/or competition with
the closely related White-lored Oriole. Competition and
replacement by related species following habitat disturbance
is occurring with the Green Racquet-tail Prioniturus luconensis,
a Luzon endemic which is being replaced by Blue-crowned
Racquet-tail P. discurus in southern Luzon (Collar et al.
1999). Effective habitat conservation is necessary and could
become a reality in the near future if conservation initiatives
in the NSMNP yield success. The observation of the Isabela
Oriole at Mansarong in 1994 (Van der Linde 1995) was not
in the NSMNP (contra Collar et al. 1999) and the Mansarong
area is not officially protected. The species has not been
observed in Bataan since 1947 (Collar et al. 1999) and in
fact only two pairs and one individual have been observed
since 1961: the pair described here, a pair in Mansarong
in 1994 (Van der Linde 1995) and an individual in Quirino
province in 1993 (Gamauf and Tebbich 1995), with the last
two observations not considered absolutely certain (Collar
1998). It seems to be defensible and suitably precautionary
to assume that not more than 250 mature Isabela Orioles
survive in the wild. Given the continued destruction and
fragmentation of Luzon’s lowland forest, the population
is likely to be declining, and each subpopulation may number
less than 50 individuals. Thus it would seem appropriate
to elevate this species to the rank of Critically Endangered,
under criterion C2a(i) of the IUCN Red List (i.e. fewer
than 250 mature individuals, all subpopulations numbering
fewer than 50 individuals and a continuing population decline).
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ACKNOWLEDGEMENTS
MvW would like to thank Dominic Rodriguez and Jessie Guerrero
who participated in fieldwork in Ambabok in 2003 and Wouter
Thijs, Marijn Prins, Edmund Jose and Rio Vinoya who were
part of the team that captured the Isabela Oriole in 2004.
RH was accompanied by Roldan Dugay during his visit in March
2003. Nigel Collar made substantial comments to an earlier
version of the paper.
REFERENCES

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Merlijn
van Weerd, Centre of Environmental Science (CML), Leiden
University, PO Box 9518, 2300Leiden, the Netherlands. E-mail:
vanweerd@cml.leidenuniv.nl Rob Hutchinson, 26 Sutton Avenue,
Chellaston, Derby DE73 1RJ, U.K. E-mail: rob_Hutchinson@btopenworld.com
Notes on Elliot’s Pheasant Syrmaticus ellioti,
Streak-breasted Scimitar Babbler Pomatorhinus ruficollis
and Mountain Scops Owl Otus spilocephalus from
Hunan, China
OLIVER KOMAR, BRETT W. BENZ and GUOJUN CHEN
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We conducted
baseline avian inventories at two reserves in Hunan, People’s
Republic of China, which were previously poorly known ornithologically.
The avifauna at both sites included a broad range of generalist
species typical of secondary vegetation and disturbed habitats.
Complete inventory results are
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available
from the University of Kansas Natural History Museum and
Biodiversity Research Center or from the authors. Here we
describe three noteworthy records: an unusual plumage of
Elliot’s Pheasant Syrmaticus ellioti, an immature
plumage of Mountain Scops Owl Otus spilocephalus, and geographic
differen-
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