SummaryIn 2013 a prediction was made that the South-East Asian subspecies of Bengal Florican Houbaropsis bengalensis blandini would be extinct within 10 years. In 2018 we conducted a survey in the Tonle Sap floodplain, Cambodia, of the last population of Bengal Florican in South-East Asia. We found that the rate of decline in displaying males was 55% over five years, a decline comparable to that recorded between 2005–2007 and 2012. The estimated number of displaying males in 2018 was 104 (95% CI: 89–117), down from 216 (156–275) in 2012. We also conducted surveys by flushing birds in the non-breeding season, which indicated that the sex ratio of males to females is 3:1. We therefore estimate that the total population of adult Bengal Floricans in Cambodia in 2018 was 138 (119–156), making H. b. blandini the most threatened bustard taxon. The number of sites that support displaying male Bengal Floricans was reduced from 10 to four between 2012 and 2018. Between 2012 and 2018 we monitored numbers of displaying males in most years at the sites that support 80% of the total population. The only site where numbers of birds are stable is Stoung-Chikraeng Bengal Florican Conservation Area, where there were 44 (25–63) displaying males in 2018. This is the only site that has an ongoing NGO-government conservation programme. Our data indicate that Bengal Floricans are lost from sites when the area of grassland falls below 25 km2. We found evidence that displaying male Bengal Floricans abandon display territories when grassland is lost, this also creates hope that they may disperse and could colonise newly created habitat. All remaining sites that support Bengal Floricans in Cambodia are imperilled and we outline what must be done to reduce the possibility that H. b. blandini will be extinct by 2023.

中文翻译：

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柬埔寨的孟加拉佛罗里达猴面包树种群灾难性地持续下降

摘要在 2013 年，有人预测孟加拉佛罗里坎的东南亚亚种孟加拉猴面包树将在10年内灭绝。2018 年，我们在柬埔寨洞里萨河漫滩对东南亚最后一批孟加拉弗洛里坎人进行了调查。我们发现，五年内展示男性的下降率为 55%，与 2005-2007 年至 2012 年记录的下降幅度相当。2018 年展示男性的估计数量为 104（95% CI：89-117），从 2012 年的 216 只（156-275 只）下降。我们还在非繁殖季节通过冲洗鸟类进行了调查，结果表明雄性与雌性的性别比为 3：1。因此，我们估计 2018 年柬埔寨成年孟加拉佛罗里达人的总人口为 138（119-156），使得H. b. 布兰迪尼最受威胁的鸨类群。2012 年至 2018 年间，支持展示男性孟加拉佛罗里达人的站点数量从 10 个减少到 4 个。在 2012 年至 2018 年期间，我们监测了大多数年份在支持总人口 80% 的站点上展示男性的数量。鸟类数量稳定的唯一地点是 Stoung-Chikraeng Bengal Florican 保护区，2018 年有 44 只（25-63 只）展示雄性鸟类。这是唯一一个正在进行非政府组织政府保护计划的地点。我们的数据表明，当草地面积低于 25 公里时，孟加拉花卉会从遗址中消失2. 我们发现有证据表明，当草原消失时，展示雄性孟加拉植物人会放弃展示区域，这也为它们可能分散并可能在新创建的栖息地定居带来了希望。在柬埔寨支持孟加拉植物人的所有剩余站点都处于危险之中，我们概述了必须采取哪些措施来减少这种可能性H. b. 布兰迪尼将在 2023 年灭绝。