Ibis (2007), 149, 328–337 © 2007 The Authors Journal compilation © 2007 British Ornithologists’ Union Blackwell Publishing Ltd Use of remote sensing to measure change in the extent of habitat for the critically endangered Jerdon’s Courser Rhinoptilus bitorquatus in India DEEPA SENAPATHI, 1 * IOANNIS N. VOGIATZAKIS, 2 PANCHAPAKESAN JEGANATHAN, 3 JENNIFER A. GILL, 1 RHYS E. GREEN, 4,5 CHRISTOPHER G. R. BOWDEN, 5 ASAD R. RAHMANI, 3 DEBBIE PAIN 5 & KEN NORRIS 2 1 Centre for Ecology, Evolution & Conservation, School of Biological Sciences, University of East Anglia, Norwich NR4 7TJ, UK 2 Centre for Agri-Environmental Research, School of Agriculture, Policy & Development, University of Reading, Reading RG6 6AR, UK 3 Bombay Natural History Society, Hornbill House, Dr Salim Ali Chowk, Shaheed Bhagat Singh Road, Mumbai 400 023, India 4 Conservation Science Group, Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK 5 Royal Society for the Protection of Birds, The Lodge, Sandy, Bedfordshire SG19 2DL, UK Jerdon’s Courser Rhinoptilus bitorquatus is one of the most endangered and least understood birds in the world. It is endemic to scrub habitats in southeast India which have been lost and degraded because of human land use. We used satellite images from 1991 and 2000 and two methods for classifying land cover to quantify loss of Jerdon’s Courser habitat. The scrub habitats on which this species depends decreased in area by 11–15% during this short period (9.6 years), predominantly as a result of scrub clearance and conversion to agriculture. The remaining scrub patches were smaller and further from human settlements in 2000 than in 1991, implying that much of the scrub loss had occurred close to human population centres. We discuss the implications of our results for the conservation of Jerdon’s Courser and the use of remote sensing methods in conservation. Globally, habitat loss and fragmentation are major threats to the continued survival of many species (Fahrig 1997, Huxel & Hastings 1999, World Resources Institute 2001). Quantifying rates of habitat loss is a vital step in understanding and prioritizing the threats facing species in different ecosystems. This is particu- larly important for endemic species, which often depend upon special habitats and are thus at greater risk of extinction through habitat degradation (Brooks et al. 2000, Norris & Harper 2004). Jerdon’s Courser Rhinoptilus bitorquatus occurs only in India and is listed as Critically Endangered by the IUCN (IUCN 2006). This nocturnal species was first described in 1848 and subsequently recorded sporadically until 1900. It was then not seen again until 1986 (Bhushan 1986). The species is known to inhabit open patches within scrub jungle bordering dry deciduous forests (Bhushan 1986) and, since its rediscovery, it has only been seen in a few restricted areas in the Cuddapah district of Andhra Pradesh, India (Jeganathan et al. 2004). Its known range is very small and it is believed to have a small and possibly declining population (BirdLife International 2001). Jerdon’s Courser can be detected using playback surveys to elicit calls (Jeganathan & Wotton 2004) and tracking strips to record footprints (Jeganathan et al. 2002). These methods have provided firm evidence of the presence of the species in a few small areas. However, there is virtually no information available about the behaviour or population ecology of the species. Nevertheless, a study of habitat use using tracking strips has identified the preferred habitat as scrub jungle with open areas where the density of large bushes (> 2 m tall) is in the range 300–700 ha -1 and the density of small bushes is < 1000 ha -1 (Jeganathan et al. 2004). Although further studies are in progress, compre- hensive population size and distribution data do not exist, individuals are rarely seen and no nest has ever *Corresponding author. Present address: Centre for Agri-Environmental Research, School of Agriculture, Policy & Development, University of Reading, Reading RG6 6AR, UK. Email: G.D.Senapathi@reading.ac.uk