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

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).

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

References

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

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

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-