Biologia

Biological Conservation 107 (2002) 111–122 www.elsevier.com/locate/biocon

The raptor community of Central Sulawesi: habitat selection and conservation status
Jean-Marc Thiollaya,*, Zaini Rahmanb
b a Laboratoire d’Ecologie, E.N.S., 46, rue d’Ulm, 75230 Paris Cedex 05, France YPAL, Yayasan Pribumi Alam Lestari, Jl. Paledang no 21 Cibeureum, Bandung 40184, West Java, Indonesia

Received 12July 2001; received in revised form 17 December 2001; accepted 19 December 2001

Abstract Diurnal raptors were surveyed in Central Sulawesi on foot in 16 sample areas, and by car along 2700 km road transects in August–September 2000. All 23 resident species were recorded and their frequency of occurrence assessed in broad habitat categories. Farmlands were unusually poor in raptors. Of their sixassociated species, the formerly common black kite (Milvus migrans) may be almost extirpated. Indiscriminate pesticide use is suspected to be a major factor. Wetlands and sea-coasts are limited in area and are also the most heavily disturbed natural habitats. All four piscivorous eagles were found to be rare or very local. Among them, only the grey-headed fishing-eagle (Ichthyophaga ichthyaetus) wasfound to be more frequent than was previously known. Excessive human fishing pressure may be the main threat, together with extensive wetland conversion into ricefields or fishponds. Forest raptors (13 species), including all Sulawesi endemic Falconiformes, were the most numerous and widespread birds of prey. Although they exhibited a fairly high tolerance to forest degradation and fragmentation(insular syndrome), their main threat is the high deforestation rate, especially the loss of the presumably more productive lowland forests. # 2002 Elsevier Science Ltd. All rights reserved.
Keywords: Falconiformes; Abundance; Habitat; Conservation; Sulawesi; Indonesia

1. Introduction Sulawesi, formerly called Celebes, is one of the ornithologically less well known regions of Indonesia. Togetherwith the Moluccas and the Lesser Sunda Islands, it forms Wallacea, a biogeographic region whose fauna has a mainly Australasian origin and composition that contrasts with the exclusively Oriental one of the Greater Sundas (Borneo, Sumatra, Java) to the West (White and Bruce, 1986; Whitten et al., 1987). Because of its high degree of endemism, Sulawesi has been identified as an Endemic Bird Area(EBA 166, Stattersfield et al., 1998) with a high priority ranking. The latest information on the avifauna of Sulawesi was summarized in White and Bruce (1986) and Coates and Bishop (1997). Six of the 23 resident diurnal raptors species are endemic to Sulawesi and two more taxa are endemic subspecies (Table 1). The remaining 15 raptor species are more widespread in south east Asia, and
*Corresponding author. E-mail address: thiollay@biologie.ens.fr (J.-M. Thiollay).

even up to India, New Guinea and/or Australia, if not further away. Due to the island situation, only three additional (uncommon) raptor species are northern wintering migrants, and none of them was recorded here. Specific surveys of raptors are few (Heinrich, in Stresemann, 1940; Coomans de Ruiter, 1947; Watling, 1983; Meyburgand Van Balen, 1994). The last survey was the most extensive and quantitatively best documented, but it covered mainly roadside (open) habitats, and only 15 of 23 resident species were recorded. The present study was part of the YPAL project (Yayasan Pribumi Alam Lestari) which focused on the distribution and conservation of the endemic Sulawesi hawk-eagle (Spizaetus lanceolatus) throughoutSulawesi. We concentrated here on the Central Sulawesi province alone, from sea level to 1700 m, where all diurnal raptors were searched for, equally, in every habitat. Central Sulawesi is less accessible than the southwestern or northeastern parts of the island, and therefore it is still the least known area of the region. It is also less populated and less deforested than the outer parts of the...