An assessment of the distribution and conservation status of hornbill species in Thailand

Abstract

Many hornbill species in Thailand are categorized as Endangered or Critically Endangered on the IUCN Red List. The objectives of this research were to predict hornbill distributions in Thailand and to assess the national conservation status of the species using extent of occurrence. We employed maximum entropy modelling, using 10 environmental variables that were believed to directly or indirectly influence hornbill distributions across Thailand, to predict the habitats potentially suitable for 10 of the country's 13 hornbill species. Data on the presence of hornbills were gathered from the Thailand Hornbill Project and additional field surveys in protected area complexes during 2004-2006. The results indicated that patch size is the most important factor affecting distribution, followed by latitude, ecoregion and distance to villages. All hornbill species were predicted to occur primarily in intact protected area complexes. The total extent of all hornbill habitats covers 9.3% of the country's land area. Seven of the 10 modelled species are at risk and the current distribution pattern is expected to reflect stochastic extinctions because of small population size. We recommend that the conservation status of Austen's brown hornbill Anorrhinus austeni and Tickell's brown hornbill Anorrhinus tickelli should be changed from Vulnerable to Endangered. The model identified five protected area complexes as hornbill hotspots in Thailand. These findings will help guide conservation management.

The future of walnut–fruit forests in Kyrgyzstan and the status of the iconic Endangered apple Malus niedzwetzkyana

“…We selected the maximum entropy model, Maxent v. 3.4.0 (Phillips et al, 2006), as suitable for modelling the distribution of M. niedzwetzkyana because it is highly accurate with small sample sizes (Elith et al, 2011; Qin et al, 2017), can be run with presence-only data (Phillips et al, 2006), and is widely used in conservation science (Trisurat et al, 2013; Liang et al, 2017). We obtained occurrence records from the Bioresurs project, which thoroughly sampled the walnut–fruit forests of the Jalal-Abad region (Cantarello et al, 2014; Orozumbekov et al, 2015), providing 28 location points for M. niedzwetzkyana.…”

Ethnoornithological study in selected villages of Riau Province, Indonesia

“…About 95% of threatened birds around the world experience habitat loss, around 70% of which are related to human activities resulting in a decline in species populations. As discussed by Franco and Minggu (2019), there was a decline in the Helmed Hornbill population in Brunei Darussalam and also in several other countries; Philippines (Gonzales 2011), Thailand (Trisurat et al 2013), India (Naniwadekar and Datta 2013;Mudappa and Raman 2009), and Malaysia (Aik and Perumal 2017). Great pressure on bird populations by humans shows that conservation measures must involve interactions between local communities and birds in the region.…”

“…However, only about 557 species have been protected by the Government Regulation of the Minister of Environment and Forestry P.106 of 2018. The increased threat of extinction is caused by intensive illegal hunting of birds which is still rife with an increasing trend from year to the year, especially for singing birds, loss of habitat due to land-use change, and the use of pesticides (Mudappa and Raman 2009;Gonzales 2011;Trisurat et al 2013;Naniwadekar and Datta 2013;Iskandar et. al.…”

Long-term monitoring of breeding successes of Great Hornbill ( Buceros bicornis ) and Rhinoceros Hornbill ( Buceros rhinoceros ) using artificial nest boxes in Budo-Su-Ngai Padi National Park, Thailand

“…The national park is in the Indo-Malayan tropical region that supports the Malaysian or Sundaic flora (Wells 1999and Woodruff 2003, as cited in Poonswad et al 2005. Budo mountain range supports six species of hornbills: Great Hornbill (Buceros bicornis), Wreathed Hornbill (Rhyticeros undulatus), Rhinoceros Hornbill (Buceros rhinoceros), Helmeted Hornbill (Rhinoplax vigil), White-crowned Hornbill (Berenicornis comatus), and Bushy-crested Hornbill (Anorrhinus galeritus; Poonswad et al 2005, Trisurat et al 2013)…”