Distribution, status and conservation of the Bengal Florican Houbaropsis bengalensis in Cambodia

Abstract

The Bengal Florican is a 'Critically Endangered' bustard (Otididae) restricted to India, Nepal and southern Indochina. Fewer than 500 birds are estimated to remain in the Indian subcontinent, whilst the Indochinese breeding population is primarily restricted to grasslands surrounding the Tonle Sap lake, Cambodia. We conducted the first comprehensive breeding season survey of Bengal Florican within the Tonle Sap region (19,500 km2). During 2005/06 and 2006/07 we systematically sampled 1-km squares for territorial males. Bengal Florican were detected within 90 1-km squares at a mean density of 0.34 males km-2 which, accounting for unequal survey effort across grassland blocks, provides a mean estimate of 0.2 males km-2. Based on 2005 habitat extent, the estimated Tonle Sap population is 416 adult males (333 - 502 ± 95% CI), more than half of them in Kompong Thom province. Tonle Sap grasslands are rapidly being lost due to intensification of rice cultivation and, based on satellite images, we document declines of 28% grassland cover within 10 grassland blocks between January 2005 and March 2007. Based on mean 2005 population densities the remaining grassland may support as few as 294 adult male florican, a decline of 30% since 2005. In response to these habitat declines almost 350 km2 of grassland have been designated as protected areas, set aside for biodiversity and local livelihoods. Conservation activities in these areas include participatory land-use zoning, patrols reporting new developments to government officials, awareness-raising and incentive-led nest protection schemes

Rapid decline of the largest remaining population of Bengal Florican Houbaropsis bengalensis and recommendations for its conservation

“…The remaining 290 squares were each surveyed twice and subsequent analysis of density considers the higher of the two counts. This contrasts with the methodology of Gray et al (2009a), who visited each of 268 survey squares just once (but with two observers, for one hour).…”

“…The substantial decline in florican numbers at Veal Srangai after 2002–2003 reflects this successional loss of grassland to scrub. Since it emerged in 2004–2005 (Gray et al 2009a), rapid, large-scale conversion of the Tonle Sap grasslands to intensive dry-season rice cultivation has become the most severe threat to the Bengal Florican remaining in Cambodia (Packman et al 2013). Dry-season rice cultivation and associated irrigation structures were responsible for 95% of grassland losses in the south-eastern region of the Tonle Sap floodplain between 2005 and 2009 (Packman et al 2013).…”

“…In calculating the overall population estimate, to account for unequal survey effort among sites, density estimates from each site were weighted both by survey effort (i.e. proportion of site surveyed) and by the relative contribution of each site to the total study area, following Greenwood and Robinson (2006) and Gray et al (2009a). We estimated detectability in 2012, comparing the numbers of floricans located during just the first or just the second round of visits to the maximum count recorded across both visits.…”

“…Grassland conversion was so rapid that in just 27 months between 2005 and 2007 the species may have lost 28% of its 2005 breeding habitat. In response, in 2007 some 349 km 2 of floodplain grassland were set aside for biodiversity and livelihood conservation, in the form of six ‘Integrated Farming and Biodiversity Areas’ (IFBAs) under declarations from the respective governors of the provinces of Siem Reap, Kompong Thom and Kompong Chhnang (Gray et al 2009a). In 2010 these were changed to ‘Bengal Florican Conservation Areas’ (BFCAs) under a declaration from the Ministry of Agriculture, Forestry and Fisheries.…”

Québec's Large‐Scale Plan Nord

“…This floodplain, which consists of inner wet grassland (flooding is longer and deeper) and outer dry grassland (flooding is shorter and shallower), is of major importance for biodiversity and livelihoods. When the grassland is exposed, it is used by 11 globally threatened bird species, including two-thirds of the world's critically endangered Bengal Floricans (Houbaropsis bengalensis) (Gray et al 2009), and it supports pastoralism, traditional low-intensity rice cultivation, and fisheries in seasonal pools. When flooded, it is vital to fisheries and contains a high diversity of watersnakes (including threatened endemic Enhydris longicauda) and many waterbirds.…”