Lyubing Zhang

Given the global scarcity of conservation resources, the "umbrella species" concept – where protecting the habitat of one targeted species indirectly benefits co-occurring species – has gained significant traction. Hainan black-crested gibbon (Nomascus hainanus), a critically endangered primate species, co-occurring with numerous forest bird species which share similar habitats, has received significant global conservation effort. In this study, to investigate whether Nomascus hainanus can be an effective umbrella species for avian community, we assessed the relationship between habitat preference and activities of the gibbon species with sympatric bird assemblages. Using passive acoustic monitoring (PAM) and automated acoustic identification, we analysed the spatial and temporal activity patterns of the focal taxa. Our results revealed shared vegetation and topographic preferences between the gibbons and birds, indicated by the co-occurrence associated with broadleaf-cornifer mixed forest habitats, higher altitudes and gentle slopes. Furthermore, the peak and the average activity levels of the gibbons were positively correlated with the overall activity level and species richness of the bird community and the omnivorous guild. These findings reveal that suitable habitats of gibbons can sustain avian diversity and activities. Our study demonstrates that the gibbons act as an effective umbrella species and the strict protection of its core habitat yields significant conservation spill-over effects for tropical avifauna. Finally, this study highlights the efficacy of PAM as a non-intrusive, long-term assessment tool for monitoring protected areas and complex ecological communities.

Climate change is altering the frequency and intensity of extreme climatic events such as tropical cyclones, raising concerns about ecological stability under these disturbances. This study examined how functional richness and functional redundancy influenced the stability of two key ecological functions—insect predation and seed dispersal—in forest bird communities with contrasting histories of cyclone exposure. Using total biomass of insectivores and frugivores as functional indicators, we found that the stability of insect predation increased with redundancy in function-delivering traits under cyclone disturbances, whereas the stability of seed dispersal was enhanced by redundancy in both function-delivering and response-related traits. In forests frequently exposed to cyclones, both functional groups occupied a smaller overall trait space, while frugivores showed greater trait similarity among individuals. These results suggest that the stability in insect predation and seed dispersal largely stems from the abundance of species performing similar functional roles. High cyclone frequency appears to exclude species with extreme traits and concentrate functional space around a few dominant species with convergent traits. Because such convergence buffers cyclone impacts, the loss of even a few redundant species could increase functional uniqueness and, consequently, reduce the functional stability of forest bird communities.

Changing drought regimes are a rising threat to biodiversity, yet their impacts on wildlife vary greatly. Acknowledging the factors associated with these consequences brings novel insights into species vulnerability resulting from extreme climatic events and facilitates effective mitigation of climate change risks. Based on 319 observations from 29 peer‐reviewed studies on birds—a well‐monitored taxonomic group—we extract the responses of demographic metrics to droughts for 204 species across eight terrestrial biomes to examine the consequences of droughts. According to relevant studies, we chose the factors potentially moderating bird demography under droughts and compiled the data for these factors from published datasets. A meta‐analysis is performed to determine the drought effect on bird demography at individual and population levels, accounting for the influence of species traits, timescale and severity of droughts, as well as biome features. The results show that droughts have an overall negative effect on bird demography, and the effect is mediated by different factors at each level. For individuals exposed to droughts, declines in demographic rates are found to be related to narrower extents of occurrence of species, and a significant overall reduction in demographic rates is identified for individuals residing in deserts and xeric shrublands. At the population level, declines in abundance or reproductive performance are generally identified for invertivores, frugivores, nectarivores and omnivores; short‐lived species with small clutch sizes also show greater susceptibilities under the impacts of droughts. Our findings additionally suggest that the demographic vulnerability of bird individuals and populations could be affected by the duration and magnitude of drought episodes. Although our results are subject to publication bias, these conclusions advance the assessment of vulnerability to extreme climatic events that used to be based on equally weighted species traits and support bird conservation by prioritizing the declining populations of species with drought‐susceptible traits.

Changing drought regimes is a rising threat to biodiversity, but reported drought impacts on species varied greatly. Acknowledging the factors associating with these impacts will bring novel understandings to species vulnerability to the changes of extreme climatic events, and facilitate effective mitigation of climate change risks. Based on the peer-reviewed studies of a well-monitored taxonomic group – birds, we examined the effects of droughts on population persistence with a focus on two aspects: population abundance and reproductive success. Responses of relevant indicators of 172 bird species were extracted across eight terrestrial biomes, and the droughts triggering these responses were measured with a climate-comparable and multi-scalar index of drought severity. A meta-analysis was then conducted for the drought effect on relative abundance and reproductive success separately, which included the temporal scale and severity of droughts, as well as biological and life-history traits of species to explain the effect. We found that droughts had an overall negative effect on bird abundance and reproductive success. Apparent abundance generally declined for severe droughts lasting over a year, while the examined responses varied greatly due to the disparities of sensitivity and plasticity among species under droughts occurring at 3-month scale. Drought-induced declines in abundance were identified for species feeding on invertebrates, fruits or nectar, and species of a smaller range showed lower reproductive success during or after droughts. A small clutch size additionally contributed to the reductions in relative abundance or reproductive success under severe droughts. Our findings indicate that bird species with above drought-susceptible traits would confront greater challenges to population persistence in the regions where the duration of severe droughts extends. The study also highlights the necessity of exploring the unknowns that lie in the links between population persistence and drought responses of bird behaviors, distribution, morphology and physiology.

Changing drought regimes is a rising threat to biodiversity, but reported drought impacts on species varied greatly. Acknowledging the factors associating with these impacts will bring novel understandings to species vulnerability to the changes of extreme climatic events, and facilitate effective mitigation of climate change risks. By compiling the responses of 172 bird species to droughts from global publications, we found bird abundance generally declined for severe droughts lasting over a year. Drought-induced declines in abundance were identified for species feeding on invertebrates, fruits or nectar. Species of a smaller range showed lower reproductive performance during or after droughts. In addition to these factors, a small clutch size also contributed to the reductions in bird abundance or reproductive performance under severe droughts. In the regions where the duration and/or intensity of severe droughts increase, bird species with above susceptible traits would confront greater risks to survival.

Ongoing perturbations in the global climate have triggered changes in the frequency or magnitude of extreme climatic events, including drought. Increasingly common or intense droughts have threatened ungulates. Intensifying trend of drought has been observed in China since the 1980s. We assessed drought vulnerability of 60 ungulate taxa distributed in China by synthesizing information on drought exposure and intrinsic vulnerability related to biological traits. In total, 27 taxa were identified as vulnerable to drought, which represent over half of the taxa assessed as threatened in the IUCN Red List and China's National Red List. We identified hotspots where a high number of drought‐vulnerable taxa are concentrated, including Northeast Himalayan subalpine conifer forests, alpine conifer and mixed forests of Nujiang‐Lancang Gorge, and Qionglai‐Minshan conifer forests, which are all located in Southwest China. We also assessed conservation efforts that China has allocated to ungulate taxa vulnerable to drought. Drought‐vulnerable taxa that are endemic to China have significantly lower coverage in China's National Nature Reserve system compared with nonvulnerable taxa. These findings reveal the gaps in existing conservation efforts and indicate possible improvements that might be needed to maintain species resistance in the face of increasing and intensifying drought impacts.

Biological invasion is one of the most threatening factors for biodiversity conservation. Lacking information on alien species in certain regions of the world hampers a balanced understanding of invasion processes and efficient data exchange among stakeholders. Current knowledge gaps are in need of urgent concern. We therefore conducted a review on alien animals in Xinjiang, an unknown region of invasion ecology. Xinjiang lies in the heartland of the Asian continent, covering an area of 1,664,900 km². In the past 64 years, 128 alien animal species were recorded in this region, 39% of which became invasive and led to loss of native biodiversity. Most of these species were introduced through diversification of local agriculture and aquaculture. This process was aggravated by improving transportation and flourishing trade. Multiple linear regression models and correlation analysis were run for explaining influence of environmental and anthropogenic factors on status of alien animals: economically developed areas with abundant water resource, oases in particular, were prone to be hotspots of alien animal species in this arid and semi-arid region. This study also revealed that taxonomically biased and lagged research were critical problems that impeded studies on biological invasions in Xinjiang, and proposed feasible solutions.