Rubber plantations are impermeable to an avian understory specialist in Sri Lanka.

BACKGROUND: Understanding how landscape characteristics affect animal movement is essential for conservation in human-dominated habitats. A fundamental question is how monoculture agroforests, including rubber and tea plantations, affect wildlife and its movement. Experimental translocations represent an important technique to assess animals' habitat selection while moving through agricultural matrices, especially when complemented with observations of birds' natural movements, and with "control" translocations, in which birds are moved within their natural habitat such as forest. Yet, experimental translocations have been little used for birds outside the Western Hemisphere. METHODS: We conducted experimental translocations and home-range measurements on an understory forest specialist, Brown-capped Babbler (BCBA, Pellorneum fuscocapillus), and a forest generalist, Tickell's Blue Flycatcher (TBFL, Cyornis tickelliae). These species were studied in three rubber plantations, which also included some open areas mostly planted with tea, and in three forest reserves of Sri Lanka. RESULTS: Four of the five BCBAs translocated within disturbed habitats (rubber plantations) could not return to their capture locations. However, all four individuals within undisturbed habitats (forest reserves) successfully returned to their point of origin within 10.5 daytime hours. In contrast, all TBFLs returned to their capture locations in both disturbed (n = 7) and undisturbed habitats (n = 3) within 11.3 daytime hours. A Cox-proportional survival model demonstrated that the percentage of rubber cover decreased return time, similar to the effect of open-area cover. The home range surveys (n = 13 for BCBA, n = 10 for TBFL) revealed that very little of the birds' natural home-ranges was covered by rubber (0.2% for BCBA, 13.1% for TBFL at 50% Kernel Density Estimates KDE). Home range size for BCBA was approximately half the size in disturbed habitats compared to undisturbed ones, although there was no significant difference between habitats for TBFL. CONCLUSIONS: We conclude that rubber plantations can be impermeable to understory habitat specialist birds, and even generalist species may avoid them long-term. Our findings highlight the potential utility of strips of native vegetation, particularly those featuring understory layers, as corridors to facilitate the movement of forest specialists in landscapes dominated by rubber plantations and other types of disturbed habitats.

Stochastic processes shape the functional and phylogenetic structure of bird assemblages at the mine area in southwest China.

Understanding the mechanisms of community assembly is a key question in ecology. Metal pollution may result in significant changes in bird community structure and diversity, with implications for ecosystem processes and function. However, the relative importance of these processes in shaping the bird community at the polluted area is still not clear. Here, we explored bird species richness, functional, and phylogenetic diversity, and the assembly processes of community at the mine region of southwest China. Our results showed that the 3 dimensions of diversity at the mine area were lower than that at the reference sites. In the community assembly, the result was 0 < NRI/ NFRI < 1.96, which indicated deterministic processes (environmental filtering) might drive community clustering. The results of the neutral community model, and normalized stochasticity ratio, showed the dominant role of stochastic processes in shaping the bird community assembly. We further quantified the community-level habitat niche breadth (Bcom), and we found that there was no difference in Bcom-value between the mine area and reference sites. This indicates that the bird communities at the mine area and 3 reference sites were not subjected to extreme environmental selection (same or different resource allocation) to form a highly specialized niche. These findings provide insights into the distribution patterns and dominant ecological processes of bird communities under metal exposure, and extend the knowledge in community assembly mechanisms of bird communities living in the mine area.

Investigating flock-associated mimicry: examining the evidence for, and drivers of, plumage mimicry in the greater and lesser necklaced laughingthrush.

Visual mimicry is less understood in birds than in other taxa. The interspecific social dominance mimicry (ISDM) hypothesis asserts that subordinate species resemble dominant ones to reduce aggression. Plumage mimicry has also been consistently noted in mixed-species flocks (MSFs), suggesting a connection to grouping behaviour, although it is unclear whether this is linked to ISDM. We studied greater necklaced laughingthrush (GNLT, Pterorhinus pectoralis) and lesser necklaced laughingthrush (LNLT, Garrulax monileger), which were recently placed in different genera. Measurements of 162 museum specimens showed LNLT converging in sympatry with GNLT in necklace colour, but diverging in necklace to body ratio, with proportionally smaller necklaces. The species were closely associated in six of seven MSF systems from Nepal to China. In a study of foraging behaviour in Nepal, aggression was rare between the species, LNLT followed GNLT and had lower foraging rates when further from GNLT. Our data suggest a link between this MSF-associated mimicry and ISDM, and that the subordinate LNLT may be the mimic and gain more from the resemblance. The species spend much time together in dense and poorly lit vegetation, where the LNLTs resemblance to GNLTs potentially allows them to forage closer to GNLTs than would be otherwise possible.

Chromosome-scale Genome assembly of the critically endangered White-eared Night-Heron (Gorsachius magnificus).

The White-eared Night-Heron (Gorsachius magnificus, G. magnificus) is a critically endangered heron that is very poorly known and only found in southern China and northern Vietnam, with an estimated population of 250 to 999 mature individuals. However, the lack of a reference genome has hindered the implementation of conservation management efforts. In this study, we present the first high-quality chromosome-scale reference genome, which was assembled by integrating PacBio long-reads sequencing, Illumina paired-end sequencing, and Hi-C technology. The genome has a total length of 1.176 Gb, with a scaffold N50 of 84.77 Mb and a contig N50 of 18.46 Mb. Utilizing Hi-C data, we anchored 99.89% of the scaffold sequences onto 29 pairs of chromosomes. Additionally, we identified 18,062 protein-coding genes in the genome, with 95.00% of which were functionally annotated. Notably, BUSCO assessment confirmed the presence of 97.2% of highly conserved Aves genes within the genome. This chromosome-level genome assembly and annotation will be valuable for future investigating the G. magnificus's evolutionary adaptation and conservation.

Audience effects in a group-living bird: How contact call rate is affected by vegetation and group size and composition.

Contact calling is a ubiquitous behavior of group-living animals. Yet in birds, beyond a general connection with group cohesion, its precise function is not well-understood, nor is it clear what stimulates changes in contact call rate. In an aviary experiment, we asked whether Swinhoe's White-eyes, Zosterops simplex, would regulate their own production of contact calls to maintain a specific rate at the group level. Specifically, we hypothesized that the sudden cessation of the group-level call rate could indicate an immediate predation threat, and we predicted that birds in smaller groups would call more to maintain a high call rate. We also investigated the effects of environmental characteristics, such as vegetation density, and social stimuli, such as the presence of certain individuals, on the rate of three different contact call types. To calculate mean individual-level rates, we measured the group-level rate and divided it by the number of birds in the aviary. We found that the individual-level rate of the most common call types increased with a greater group size, the opposite pattern to what would be expected if birds were maintaining a specific group-level rate. Vegetation density did not affect any call rate. However, individual-level rates of all call types decreased when birds were in subgroups with individuals of differing dominance status, and the rate of some call types increased when birds were with affiliated individuals. Our results do not support the hypothesis that contact calls are related to habitat structure or immediate predation risk. Rather, they appear to have a social function, used for communication within or between groups depending on the call type. Increases in call rates could recruit affiliated individuals, whereas subordinates could withhold calls so that dominants are unable to locate them, leading to fluctuations in contact calling in different social contexts.

Public Opinions on Stray Cats in China, Evidence from Social Media Data.

The management of stray cats is often contentious because public perceptions about these animals are different. Using user-generated content from Weibo, this study investigated Chinese citizens' opinions on stray cats on a large scale. Through the techniques of natural language processing, we obtained each Weibo post's topics and sentiment propensity. The results showed that: (1) there were some irresponsible feeding behaviors among citizens; (2) public perceptions of the ecological impacts caused by stray cats were unlike; (3) the trap-neuter-return (TNR) method served high support in public discussion; (4) knowledge about stray cats' ecological impacts was positively correlated with support for the lethal control methods in management. Based on these findings, we suggested that management policies should be dedicated to (1) communicating to the (potential) cat feeders about the negative aspects of irresponsible feeding behaviors; (2) raising "ecological awareness" campaigns for the public as well as highlighting the environmental impacts caused by stray cats; (3) understanding citizens' perceptions toward different management scenarios and making decisions accordingly. In addition, this study also suggested that social media data can provide useful information about people's opinions on wild animals and their management. Policies would benefit by taking this source of information into the decision-making process.

Comparison of gut microbiota between immigrant and native populations of the Silver-eared Mesia (Leiothrix argentauris) living in mining area.

The complex gut bacterial communities have a major impact on organismal health. However, knowledge of the effects of habitat change on the gut microbiota of wild birds is limited. In this study, we characterized the gut microbiota of two different subspecies of the Silver-eared Mesia (Leiothrix argentauris), the native subspecies (L. a. rubrogularis) and immigrant subspecies (L. a. vernayi), using 16S rRNA gene high-throughput sequencing. These two subspecies live in a trace metal-contaminated area, and L. a. vernayi was trafficked. They are an excellent system for studying how the gut microbiome of wild animal changes when they move to new habitats. We hypothesized that the immigrant subspecies would develop the same adaptations as the native subspecies in response to habitat changes. The results showed that there were no significant differences in the composition, diversity, or functional metabolism of gut microbiota between native and immigrant subspecies under the combined action of similar influencing factors (the p values of all analyses of variance >0.05). In addition, the composition and functional metabolism of gut microbiota in two subspecies showed adaptation against trace metal damage. Linear discriminant analysis effect size (LEfSe) analysis revealed that Massilia in the intestinal microbiota of immigrant subspecies was significantly higher than that of native subspecies, suggesting that immigrant subspecies suffered habitat change. Finally, we found that these two subspecies living in the mining area had an extremely high proportion of pathogenic bacteria in their gut microbiota (about 90%), much higher than in other species (about 50%) living in wild environment. Our results revealed the adaptation of intestinal microbiota of immigrant Silver-eared Mesias under heavy metals stress, which would provide guidance for biodiversity conservation and pollution management in mining area.

Metal and metalloid sources apportionment in soil of two major agroecosystems of southern China.

Apportioning the sources of metals/metalloids is a critical step toward soil quality protection and ecological restoration. The objective of this study was to identify the potential sources of contamination of As, Cd, Cr, Cu, Hg, Mn, Pb, and Zn, and determine the contribution rates of each source, to rice and sugarcane agroecosystems of southwestern Guangxi, southern China. We collected a total of 300 soil samples at a former lead-zinc mine and at two reference sites, 6 and 60 km away from the mine, sampling both agroecosystems at each site. Overall, the positive matrix factorization (PMF) receptor model revealed that in rice paddies at the mine site, mining activities had the highest contribution (60.7% of all examined metals/metalloids), followed by irrigation (25.8%), and agrochemical application (13.5%). At the close reference site, agrochemical application contributed 42.8%, followed by irrigation (22.7%), natural sources (17.4%), and mining activities (17.2%). At the far reference site, agrochemical application was predominant (40.6%), followed by irrigation (32.5%), and natural sources (26.9%). In comparison, at the mine site and the close reference site in sugarcane ecosystems, agrochemical application was predominant (50.1% and 57.4%, respectively), followed by mining activities (49.9% and 42.6%). At the far reference site, agrochemical application contributed 51.2%, followed by natural sources (48.8%). Therefore, the PMF model indicated that the optimal solution was four or three sources per site for rice paddies, but only two sources per site for sugarcane, suggesting that sources of metal/metalloid contamination were more complicated in rice paddy than in sugarcane agroecosystems.

Multiple trace elements exposure of Grey-cheeked Fulvettas Alcippe morrisonia, a nuclear member in bird mixed-species flocks, and implications for bioindicator.

Birds are vulnerable to metal pollution, which can serve as indicators of environmental safety monitoring. In this study, we evaluated three non-essential (Pb, Cd, and As) and two essential (Cu and Zn) trace elements of living (only feathers) and deceased (feathers and tissues) Grey-cheeked Fulvetta (Alcippe morrisonia) at a highly polluted mine tailings and a reference site. Five metal concentrations in the feathers of living Grey-cheeked Fulvettas were higher at the mine site. Among these, the levels of Cd and Pb in most feathers exceeded the threshold, resulting in an ecotoxicological concern. The correlation analysis suggested that feathers from Grey-cheeked Fulvettas might be useful bioindicators for local metal contamination assessment. The toxicological effects of trace metals on Grey-cheeked Fulvetta might affect its leadership ability. Therefore, understanding the effects of metal pollution on Grey-cheeked Fulvetta would show important practical implications for the conservation of bird communities.

Increasing collaboration between China and India in the environmental sciences to foster global sustainability.

As the two largest countries by population, China and India have pervasive effects on the ecosphere. Because of their human population size and long international boundary, they share biodiversity and the threats to it, as well as crops, pests and diseases. We ranked the two countries on a variety of environmental challenges and solutions, illustrating quantitatively their environmental footprint and the parallels between them regarding the threats to their human populations and biodiversity. Yet we show that China and India continue to have few co-authorships in environmental publications, even as their major funding for scientific research has expanded. An agenda for collaboration between China and India can start with the shared Himalaya, linking the countries' scientists and institutions. A broader agenda can then be framed around environmental challenges that have regional patterns. Coordinated and collaborative research has the potential to improve the two countries' environmental performance, with implications for global sustainability.

Passerine bird reproduction does not decline in a highly-contaminated mercury mining district of China.

Mercury (Hg) is a neurotoxic element with severe effects on humans and wildlife. Widely distributed by atmospheric deposition, it can also be localized near point sources such as mines. Mercury has been shown to reduce the reproduction of bird populations in field observations in North America and Europe, but studies are needed in Asia, where the majority of emissions now occur. We investigated the reproduction of two passerines, Japanese Tit (Parus minor) and Russet Sparrow (Passer rutilans), in a large-scale Hg mining district, and a non-mining district, both in Guizhou, southwest China. Concentrations of Hg were elevated in the mining district (blood levels of 2.54 ± 2.21 [SD] and 0.71 ± 0.40 µg/g, in adult tits and sparrows, respectively). However, we saw no evidence of decreased breeding there: metrics such as egg volume, nestling weight, hatching and fledgling success, were all similar between the different districts across two breeding seasons. Nor were there correlations at the mining district between Hg levels of adults or juveniles, and hatching or fledgling success, or nestling weight. Nest success was high even in the mining district (tit, 64.0%; sparrow: 83.1%). This lack of reproductive decline may be related to lower blood levels in nestlings (means < 0.15 µg/g for both species). Concentrations of selenium (Se), and Se-to-Hg molar ratio, were also not correlated to breeding success. Although blood levels of 3.0 µg/g have been considered as a threshold of adverse effects in birds, even leading to severe effects, we detected no population-level reproductive effects, despite ~25% of the adult tits being above this level. Future work should investigate different locations in the mining district, different life-stages of the birds, and a wider variety of species. The hypothesis that bird populations can evolve resistance to Hg in contaminated areas should also be examined further.

Strictly protected areas are not necessarily more effective than areas in which multiple human uses are permitted.

The International Union for Conservation of Nature (IUCN) classifies protected areas into six categories, ranging from strict nature reserves to areas where multiple human uses are permitted. In the past, many researchers have questioned the effectiveness of multiple-use areas, fueling an unresolved debate regarding their conservation value. The literature so far has been inconclusive: although several studies have found that strictly protected areas are more effective, others have found the opposite, and yet others that the two types do not differ. To help resolve this debate, we reviewed the literature on protected areas and conducted our own analysis using > 19 000 terrestrial protected areas worldwide. We found that the differences between strictly protected areas and areas in which multiple human uses are permitted are often small and not statistically significant. Although the effectiveness of protected areas worldwide varies, other factors, besides their assigned IUCN category, are likely to be driving this pattern.

Heavy Metal, Arsenic, and Selenium Concentrations in Bird Feathers from a Region in Southern China Impacted by Intensive Mining of Nonferrous Metals.

Heavy metal pollution is widespread in China, particularly in its mining regions. Mercury (Hg) concentrations in birds from Guizhou Province were recently reported to be above adverse effect levels, even in nonmining areas. We sampled birds to investigate whether Hg might be a threat near lead (Pb), zinc (Zn), and tin (Sn) mines in Guangxi Zhuang Autonomous Region. We measured concentrations of 8 metals/metalloids in feathers of 627 resident birds representing 60 species sampled across 14 sites on 5 rivers. We found that Hg concentrations (mean ± standard deviation, 1.27 ± 2.02 ppm) were lower than in the recent Guizhou study. Mercury had the fewest correlations with other metals/metalloids; the mined metals (Pb, Sn, Zn) had the most such correlations. Levels of cadmium (Cd; 1.12 ± 2.64 ppm), arsenic (As; 4.78 ± 17.11 ppm), and Pb (17.18 ± 24.49 ppm) were closer to thresholds of adverse effects or relatively high compared to other studies. With the exception of a few hot spots for Hg, Cd, and As near mines, metal/metalloid levels were fairly evenly distributed among sites, consistent with the regional occurrence of mineable ore deposits. It appears that Hg is not threatening to all avian species in China, although it may be problematic for some species near Hg mines. In addition to Hg, however, other metals/metalloids may pose wildlife health hazards. Environ Toxicol Chem 2020;39:371-380. © 2019 SETAC.

Disappearance of endangered turtles within China's nature reserves.

China ranks first among Northern hemisphere countries for species richness, but approximately 43% of its species are threatened [1], with harvesting being the major threat to vertebrates [2]. To protect its biodiversity, China has established about 2,700 nature reserves covering 1.46 million km2 ( about 15% of China's territory, a percentage higher than the world average [3]). With increasing habitat destruction and harvesting, nature reserves are the final refugia for threatened species. However, many Chinese nature reserves are poorly managed, leaving them vulnerable to poaching and other human encroachment [4]. In this study, we conducted a 12-year (2002-2013) case study on turtles to illustrate the damaging impacts China's nature reserves have on wildlife conservation. We discovered that poaching occurred in all of the 56 reserves surveyed, resulting in dramatically reduced turtle populations. In a majority of the reserves, the reserve staff themselves were involved in poaching. Although nature reserves were created to protect plants and animals, they have become part of the problem due to weak enforcement of rules.

Multi-locus analysis supports the taxonomic validity of Arborophila gingica guangxiensis Fang Zhou & Aiwu Jiang, 2008.

The taxonomic status of subspecies has long been debated, especially in conservation biology. Some proposed subspecies must be evolutionarily distinct to be considered conservation units. White-necklaced Partridge (Arborophila gingica) comprises two subspecies, Arborophila gingica gingica and Arborophila gingica guangxiensis. Arborophila gingica guangxiensis, restricted to three isolated small areas in Guangxi, China, with limited population sizes, is a newly discovered subspecies based on recently identified geographic and phenotypic differences between Arborophila gingica gingica; however, evidence is lacking that can effectively identify whether the subspecies is evolutionarily distinct. Here, three mitochondrial DNA segments and four nuclear introns were used to test whether the two subspecies are reciprocally monophyletic, which has been proposed as an objective method to evaluate evolutionary distinctiveness. The results indicate that the two subspecies are genetically divergent and form reciprocal monophyletic groups. Therefore, this study further supports the taxonomic validity and distinctiveness of Arborophila gingica guangxiensis and suggests that this subspecies be considered as a conservation unit.

Update on the distribution range of the white-browed crake (Porzana cinerea): a new record from mainland China.

Since 1980, the white-browed crake (Porzana cinerea) has been experiencing an expansion from south of the Isthmus of Kra, northward to China. Recently, this species was observed in several locations throughout Southwest China, including Ningming and Baise, Guangxi (2012, 2013), and Xichang, Sichuan (2013). These sightings are the first distribution record of this species in mainland China, suggesting that the white-browed crake is following a natural species dispersal northward into mainland China from Southeast Asia.

[A new record of the bird subspecies Black-crested Bulbul (Pycnonotus flaviventris johnsoni) in China].

Several Black-crested Bulbul (Pycnonotus flaviventris) with red throats were observed and photographed in December 2010 and April 2011 in the Youjiang District (N23(o)54', E06(o)36', altitude 179 m) and Jingxi County(N22(o)59', E1 06(o)40', altitude 354 m) of Baise city, northwestern Guangxi, in southern China. These individuals belong to subspecies johnsoni, recorded previously in central and southeastern Thailand as well as the southern Indochina Region. This sighting provides a new record of the subspecies within China, warranting a discussion on the classification and distribution of Pycnonotus flaviventris.

[Seasonal feeding site selection of the Nonggang Babbler (Stachyris nonggangensis) in Nonggang, Guangxi, China].

We investigated the feeding sites of the Nonggang Babbler (Stachyris nonggangensis) during three time periods (July-September, 2010; November-December, 2010; January-February, 2011) in Nonggang National Nature Reserve, Guangxi, China with the line transect method and sampling method. Principal component analysis of the data identified that the feeding sites in the rainy season were dominated by factors consisting of tree layer, the layer of fallen leaves and the herb layer; whereas the feeding sites in the dry season were dominated by factors dependant on terrain, herb layer and shrub layer. The results of a circular distribution analysis showed that the Nonggang Babbler preferred feeding sites with a gentle slope in both the rainy season and dry season. The tests of differences of the variables between used and control plots indicated that with low arbor coverage in the rainy season, whereas with a low slope position, high shrub and thick fallen leaves in the dry season. In comparison with the rainy season, the feeding sites in the dry season tended to be at lower altitude, to have a lower slope position, lower grass coverage, and to be covered with a larger and thicker bed of fallen leaves. A logistic regression analysis suggested that altitude, slope, and shatter cover were the most important factors influencing feeding site selection in the rainy season. Slope position, arbor cover, grass cover, and the thickness of the shatter cover were the most important factors influencing feeding site selection in the dry season.