Avian mixed-species flocks (MSFs) are an important example of species interactions threatened by the biodiversity crisis. They are found throughout the world in forested habitats but are generally reduced in size or frequency by human disturbance. In southern China, a unique MSF system is led by several species of closely- related fulvettas (Alcippe morrisonia, A. hueti, and A. davidi). Our objective was to understand how this system is distributed across elevational gradients, especially moving west into the Hengduan Mountains, and how it responds to human disturbance. We sampled leadership and composition of 375 MSFs over 2 yr in and surrounding 5 nature reserves in Guangxi Zhuang Autonomous Region and Yunnan Province, with transects placed in different land use types—protected forest, buffer areas, or agriculture—and ranging from 400 to 3,200 m. We also sampled birds outside of MSFs. We found MSFs led by fulvettas (A. fratercula and A. davidi) in forests across the region up to 2,900 m. Elevation was not a significant influence on MSF size or prevalence in models that also included land use. We found that MSFs were encountered at only one-third of the frequency in agriculture as in forest, and had strongly different composition and leadership. Although MSFs in buffer areas were more similar to those in forest, birds in buffer areas had lower flocking propensity, different flock leaders, and less complex social networks. In particular, buffer transects that were seeded pine had low numbers of fulvetta-led MSFs and forest specialists in MSFs. In the future, it is important to understand which vegetational characteristics allow MSFs, particularly fulvetta-led MSFs, to persist in buffer habitats.

Encouraging crop diversity could be a “win–win” for farmers and biodiversity conservation, if having a variety of crops produces the heterogeneity that supports biodiversity, and if multiple crops decrease the risk of farmers to losses due to pests, climatic events or market fluctuations, without strongly reducing their incomes. However, data on the factors that influence the decision to plant multiple crops, and how that affects profit, are needed, especially for East Asia, where these questions have been little studied. We distributed a questionnaire on these issues to 301 farmers in 35 villages in an agricultural area close to the city of Nanning in Guangxi, south China. Crop diversity increased with land size and closeness to the city. We detected no relationship between profit variability and crop diversity, but farmers with greater crop diversity and more land were more profitable, a result driven by several rarely planted but lucrative types of crops. Crop diversity can be a focus for policy to improve farmers’ livelihoods; these policies need to encourage farmers with little land to form cooperatives. Further research is needed to understand the effect of crop diversity on profit variability, and in areas closer to protected areas where biodiversity is higher.

Background The breeding information of most birds in Asian tropical areas, especially in limestone forests, is still poorly known. The Streaked Wren-Babbler (Napothera brevicaudata) is an uncommon tropical limestone bird with a small range. We studied its nest-site selection and breeding ecology, in order to understand the adaptations of birds to the conditions of tropical limestone forest in southern China. Methods We used methods of systematical searching and parent-following to locate the nests of the Streaked Wren-Babbler. We measured characteristics of nest sites and rock cavities. Data loggers and video cameras were used to monitor the breeding behavior. Results All the observed nests of the Streaked Wren-Babbler were placed in natural shallow cavities or deep holes in large boulders or limestone cliffs. The great majority (96.6%) of Streaked Wren-Babbler nests had three eggs with an average fresh weight of 3.46 ± 0.43 g (n = 36, range 2.52‒4.20 g). Most (80.4%) females laid their first eggs between March and April (n = 46). The average incubation and nestling period of the Streaked Wren-Babbler was 10.2 ± 0.4 days (n = 5, range 10‒11 days) and 10.5 ± 0.8 days (n = 6, range 9‒11 days), respectively. Most (87.9%) nests had at least one nestling fledge between 2011 and 2013 (n = 33). Conclusions Our study suggests that several features of the breeding ecology of the Streaked Wren-Babbler, including building nests in rocky cavities, commencing breeding earlier than most species, and reducing foraging times during the incubation period, are well-adapted to the unique habitat of tropical limestone forest