Seasonal landscape use and conservation of a critically endangered bustard: Bengal florican in Cambodia Charlotte E. Packman Thesis submitted for the degree of Doctor of Philosophy at the University of East Anglia September 2011 © This copy of the thesis has been supplied on condition that anyone who consults it is understood to recognise that its copyright rests with the author and that use of any information derived there from must be in accordance with current UK Copyright Law. In addition, any quotation or extract must include full attribution. Contents Page Abstract ii Acknowledgements iii Chapter 1: 1 General introduction Chapter 2: 15 Accelerating conversion of the last of Southeast Asia’s flooded grassland biome Chapter 3: 33 Wet season migration and distribution of Bengal floricans in Cambodia: patterns, timing and implications for conservation Chapter 4: 66 Non-breeding habitat use of Bengal floricans in Cambodia and implications for conservation Chapter 5: 90 Spatial and temporal patterns of home range occupancy and habitat use of breeding Bengal floricans in Cambodia Chapter 6: 119 Conclusions Appendix: 138 Catching Bengal floricans to deploy transmitters i Abstract The world’s rarest bustard, the Critically Endangered Bengal florican Houbaropsis bengalensis, is found in two disjunct regions: the Indian subcontinent and South-East Asia. Two-thirds of the remaining population occupy the floodplain grasslands of the Tonle Sap lake, Cambodia. Producing an up-to-date landcover map of this area enabled recent habitat changes to be assessed. Nearly a fifth of the grassland in the key remaining area was lost in just four years (2005–2009) to intensive commercial rice cultivation. To date, research and conservation efforts have focused on the distribution and habitat of male floricans during the core breeding period (mid-February–early June). However, at the onset of the wet season, the floricans’ grassland habitat floods, and their movements, distribution, habitats and threats are poorly understood. Using satellite-telemetry, movements of both sexes (from five breeding sites) were tracked throughout the year. When breeding, home ranges were an order of magnitude larger than previously determined from radio- tracking. Females had larger home range core areas than males, and pre- and post-breeding movements were wider than during the core breeding period. Current protected areas may therefore be insufficient. Grassland was the only habitat type selected and smaller home ranges contained a higher proportion of grassland cover. Wet season migration is facultative: some birds remain if the breeding grasslands are sufficiently dry. Floricans were strongly site faithful in both breeding and non-breeding ranges. Migratory floricans were tracked to non-breeding areas, up to 42 km from breeding sites. Birds from three northern and two southern breeding sites did not overlap in non-breeding areas. Floricans favour open savanna habitat and avoid agriculture and closed-canopy forest. Different conservation approaches are required for the northern and southern areas. In the north suitable habitat remains but is threatened by plantations. The location of protected areas needs reconsideration as they were little used by tagged birds and contained much unsuitable habitat. In the south, land is dominated by agriculture: habitat restoration and protection are required. ii Acknowledgements The work presented in this thesis would not have been possible without the help and support of a number of people. First and foremost, I have been extremely fortunate to have been supervised by Paul Dolman and Nigel Collar. I can not thank them enough for their tremendous support, encouragement, help and fantastic advice, every step of the way. They have been unfalteringly positive throughout, and despite both being incredibly busy people, have always made time to help me whenever I have needed it. Thanks to everyone who has supported me during fieldwork in Cambodia. Especially Son Virak, my long-suffering field assistant, who has shown absolute dedication and commitment and worked exceptionally hard, throughout many months of intense fieldwork, to help me with data collection (with never a word of complaint!). He has been incredibly patient and guided me through the many challenges of fieldwork in Cambodia. I am also extremely grateful for assistance during the long days of florican catching from Markus Handschuh, who has been inspirational, and helped make the impossible, possible. Thanks to the Wildlife Conservation Society in Cambodia for giving guidance and support, especially Tom Evans, Robert van Zalinge and Hong Chamnan. My sincere thanks also to all those who have helped with fieldwork at one time or another: Richard Hillard, Chim Sochenda, Ro Borey, Robert Thomson, Sebastien Caron, Jonathan Eames, Dave Dowson, Mr Mao, Mr Mon and Craig Symes. My thanks to Tom Gray for useful discussions about floricans and to Andrew Lovett, for all his advice on GIS aspects. The Emirates Centre for Wildlife Propagation (Morocco) trained me in techniques for handling bustards and fitting harness transmitters as well as radio-tracking skills, for which I am particularly grateful to Yves Hingrat and Eric Le Nuz. Jacky Judas and Olivier Combreau have also offered helpful advice about satellite tracking. I am grateful to all those in the Cabbage Lab, and adjacent corridors in BIO and ENV, for their entertainment, support, excellent advice and helpful discussions: Christina Ieronymidou, Hugh Wright, Kabelo Senyatso, Katrina Evans, Catriona Morrison, Freydis Vigfusdottir, Daniel Hayhow, Jose Alves, Kelly Edmunds, Sian Diamond, Danielle Peruffo, Dave White, Sue Palminteri, Veronica iii Mendez, Richard Davies, Jenny Gill, Iain Barr, Anna Millard, James Kitson, Lucy Friend, Phil Leftwich and Amy Romans. Finally thanks to my parents, Lyn and Martin, for their unfaltering support and encouragement throughout this (mad) endeavour. This PhD studentship was funded by the Natural Environment Research Council, with BirdLife International as the CASE partner. Funding for fieldwork, transmitters and equipment was provided by: Critical Ecosystem Partnership Fund, Mohammed bin Zayed Species Conservation Fund, National Avian Research Centre - International Fund for Houbara Conservation, Chester Zoo/North of England Zoological Society, North Star Science & Technology, Ford Motor Company, BirdLife International in Indochina and the Wildlife Conservation Society. iv Chapter 1: General introduction 1 Chapter 1: General introduction Knowledge constraints on effective conservation Effective conservation of a threatened species requires a thorough understanding of its ecology. However, for many rare species, particularly in the tropics, this knowledge has never been generated and is difficult to obtain owing to behavioural, environmental, logistical and/or socio-political factors. Increasingly, however, technological advances are helping to overcome these constraining factors, providing a means of investigating aspects of species’ biology that were not previously accessible to scientific study. A major example of this are the developments made in remote sensing, with satellites providing a means to track the movements of individuals fitted with transmitters, as well as to produce high resolution images of large areas of land. Both of these applications of remote sensing are rapidly becoming indispensable tools in conservation biology. Satellite-tracking systems have hugely improved our understanding of animal movement patterns. As technology has advanced, transmitter size has decreased, opening up the application of satellite-tracking to a growing number of species. This has facilitated substantial progress in the understanding of migratory patterns, routes and destinations of little known and difficulty-to-study species, and proved an important tool in gaining information necessary for the effective conservation of threatened species (Hebblewhite and Haydon, 2010). Similarly, as the resolution of satellite imagery has improved, its usefulness for conservation biology has increased (Turner et al., 2003). Detailed and up-to-date landcover maps often do not exist where they are most needed, in areas with the richest biodiversity facing the greatest threats. It is highly unlikely that the necessary information required to meet these threats can be obtained by field-based methods alone (Heywood, 1995), although clearly it is important to support remotely sensed data with field-based measures (Kerr and Ostrovsky, 2003). Mapping habitat across large landscapes on foot is hugely time-consuming, expensive and difficult to keep updated, and is particularly problematic (and important) in landscapes undergoing rapid change (Bock, 2003). The use of satellite imagery to map habitats is far more efficient, can be regularly updated and is increasingly affordable. Progressively finer resolution satellite images are available; and although higher-resolution images are still prohibitively expensive, Landsat 7 ETM+ images are now free, and with a resolution of 30 x 30 m they have many useful applications. These include: mapping habitat covers and landuse change, determining habitat correlates of species distributions, and identifying potential areas of suitable/important habitat to guide subsequent field-based surveys (improving efficiency). 2 Chapter 1: General introduction Threatened migratory species arguably present the greatest challenge, both to obtaining adequate knowledge of the threats they face