Modeling the distribution of Nonggang Babbler Stachyris nonggangensis, a threatened bird of limestone karst forests of the Sino-Vietnam border, and implications for its conservation

Abstract

SummaryInformation on the geographic distribution of a species is fundamental for its conservation. Nonggang Babbler Stachyris nonggangensis (NB) is a rare and newly discovered species that is restricted to limestone karst forest on the Sino-Vietnamese border and has been classified as ‘Vulnerable’ due to its narrow distribution. However, the extent of the habitat suitable for NB is poorly known. We conducted a species distribution model (SDM) using 33 occurrence data and nine environmental variables. The SDM suggested highly suitable habitat covers 541 km2, and habitat with a medium and low level of suitability covers 3,218 km2 and 722 km2, respectively. Of the entire suitable habitat (low through high), 25.8% is in northern Vietnam and the rest is in Guangxi Zhuang Autonomous Region, southern China (especially concentrated in northern Longzhou and southern Daxing Counties). Unfortunately, only 12.4% of the entire suitable habitat is known to be occupied, and the habitat outside the reserves is highly threatened by fragmentation and degradation. Globally, NB is apparently isolated in only four sites, including one site in which we discovered its presence during field validation of the model. Based on this work, we suggest upgrading NB to the ‘Endangered’ category on the IUCN Red List and adding it to the list of endangered species of both China and Vietnam.

Abundance and habitat associations of the globally endangered Giant NuthatchSitta magnain Southern Shan State, Myanmar

“…A variety of factors such as narrow geographic ranges, small populations and/or greater susceptibility to environmental factors such as climate change, places certain species at elevated risk of extinction (Sousa-Silva et al 2014). Habitat associations and geographic distributions of rare and threatened species need to be understood in detail for effective conservation and management (Jiang et al 2020). However, field surveys to acquire this kind of information may be limited by difficult climatic conditions or because areas are inaccessible due either to topographic, political, or security constraints, as often with transboundary areas (Goodale et al 2003).…”

Effects of Climate Change on the Distribution of Threatened Fishing Bat Myotis pilosus in China

“…Although the data set of distribution is small, our simulation shows a high accuracy (Figure 2a). Similarly, Jiang et al (2020) used MaxEnt to predict the suitable habitat of Stachyris nonggangensis with 33 occurrence records with a model accuracy of 0.99 [55], indicating that the model performed well with limited data. Silva et al (2014) used only 17, 25, and 6 occurrence points to estimate the potential distribution of endemic lizard species Tropidurus montanus, Cercosaura albostrigata, and Bachia oxyrhina in the Brazilian Cerrado hotspot; the model accuracies were 0.99, 0.94, and 0.99, respectively [56], also suggesting that MaxEnt can obtain accurate simulation results with small data sets [57,58].…”

Intimacy across species boundaries: Interspecific allopreening between Spot‐necked (Stachyris strialata) and Nonggang Babblers (S. nonggangensis)

“…These species are Spot‐necked ( Stachyris strialata , hereafter “SNB”) and Nonggang Babblers ( Stachyris nonggangensis , hereafter “NB”). While SNB occurs from southern China to southern Sumatra (Collar & Robson, 2020 ), NB is only found in the limestone forest in southern China and northern Vietnam (Jiang et al, 2020 ). In regions where these two species co‐occur, they often form mixed‐species aggregations in bird blinds (W. Zhou, Z. Zhang, pers.…”