While many factors explain the colour of fleshy fruits, it is thought that black and red fruits are common in part because frugivorous birds prefer these colours. We examined this still controversial hypothesis at a tropical Asian field site, using artificial fruits, fresh fruits, four wild-caught resident frugivorous bird species, and hand-raised naïve birds from three of the same species. We demonstrate that all birds favored red artificial fruits more than yellow, blue, black and green, although the artificial black colour was found subsequently to be similar to the artificial blue colour in its spectral reflectance. Wild-caught birds preferred both black and red fleshy natural fruits, whereas hand-raised naïve birds preferred black to red natural fleshy fruits and to those of other colours. All birds avoided artificial and naturally ripe green fruits. The inter-individual variation in colour choice was low and the preferences were constant over time, supporting the hypothesis that bird colour preferences are a contributing factor driving fruit colour evolution in tropical Asia.

Chang, C. H., M. L. Barnes, M. Frye, M. Zhang, R.-C. Quan, L. M. G. Reisman, S. A. Levin, and D. S. Wilcove. 2017. The pleasure of pursuit: recreational hunters in rural Southwest China exhibit low exit rates in response to declining catch. Ecology and Society 22(1):43. https://doi.org/10.5751/ES-09072-220143

Transboundary conservation is playing an increasingly important role in maintaining ecosystem integrity and halting biodiversity loss caused by anthropogenic activities. However, lack of information on species distributions in transboundary regions and understanding of the threats in these areas impairs conservation. We developed a spatial conservation plan for the transboundary areas between Yunnan province, southwestern China, and neighboring Myanmar, Laos, and Vietnam in the Indo‐Burma biodiversity hotspot. To identify priority areas for conservation and restoration, we determined species distribution patterns and recent land‐use changes and examined the spatiotemporal dynamics of the connected natural forest, which supports most species. We assessed connectivity with equivalent connected area (ECA), which is the amount of reachable habitat for a species. An ECA incorporates the presence of habitat in a patch and the amount of habitat in other patches within dispersal distance. We analyzed 197,845 locality records from specimen collections and monographs for 21,004 plant and vertebrate species. The region of Yunnan immediately adjacent to the international borders had the highest species richness, with 61% of recorded species and 56% of threatened vertebrates, which suggests high conservation value. Satellite imagery showed the area of natural forest in the border zone declined by 5.2% (13,255 km ² ) from 1995 to 2018 and monoculture plantations increased 92.4%, shrubland 10.1%, and other cropland 6.2%. The resulting decline in connected natural forest reduced the amount of habitat, especially for forest specialists with limited dispersal abilities. The most severe decline in connectivity was along the Sino‐Vietnamese border. Many priority areas straddle international boundaries, indicating demand and potential for establishing transboundary protected areas. Our results illustrate the importance of bi‐ and multilateral cooperation to protect biodiversity in this region and provide guidance for future conservation planning and practice.

Spider nursery: Mammals produce milk to feed their offspring, and maternal care often continues well after the young can forage for themselves. Though other cases of milk-like secretions have been found, this combination of ongoing maternal care has largely been considered a uniquely mammalian trait. Chen et al. describe an ant-mimicking jumping spider that secretes a nutritious milk-like substance on which its young offspring are entirely dependent. The spider also continues to care for the spiderlings as they mature and become independent. Thus, this type of maternal care may be more widespread than has been assumed. Science , this issue p. 1052

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.