Wambura M. Mtemi

Birds serve as ecological bioindicators of metal/metalloid contamination due to their continuous environmental exposure. In northeast China, where metal/metalloid pollution is a serious environmental issue driven by anthropogenic activities, its effects on birds remain understudied. This study analyzed tail feathers from ten terrestrial raptor species across four families to assess ecological risks from cadmium (Cd), lead (Pb), arsenic (As), zinc (Zn), copper (Cu), and manganese (Mn). Results showed that Tiger Shrike (Lanius tigrinus) had the highest As (54.35 ± 69.76 mg kg⁻¹) and Cd (5.45 ± 3.94 mg kg⁻¹) residues, followed by Brown Shrike (Lanius cristatus), which also exhibited elevated Pb concentrations (33.61 ± 93.20 mg kg⁻¹). This suggests Shrikes (Laniidae) are more susceptible to metal/metalloid contamination. Significant differences in pollutant levels were found between Little Owl (Athene noctua) and Long-Eared Owl (Asio otus), despite similar feeding behaviors, indicating species-specific sensitivity. Stable carbon isotopic (δ¹³C) values suggested that predatory birds feeding in habitats with lower δ¹³C values may have greater exposure to metal/metalloid pollutants. All studied predatory bird species, except Long-Eared Owl, showed at least one metal/metalloid concentration above toxicity thresholds, highlighting potential ecological risks. These findings emphasize the need for stringent control of anthropogenic metal emissions to mitigate adverse effects on wildlife and human health.

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.

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.

The need for rapid development in developing countries has led to establishment of major public infrastructure even in biodiversity rich protected areas. Mikumi National Park in central Tanzania is traversed by five such major infrastructures namely an optic fibre, a busy public road, an oil pipeline, power lines and railways. We assessed diversity and abundance of small terrestrial mammals of the order Eulipotyphla and Rodentia as indicator groups in relation to impacts of such infrastructure. Animals were live trapped during wet (February-April) and dry (July- September) seasons in 2018 from three established plots along the three transects set perpendicular to each of the four infrastructures. In 10102 trap nights, we captured 453 small mammals of nine species of which Mastomys natalensis constituted 75.4 % of total catch. Diversity and abundance varied between seasons, infrastructure and plots location. Dry season had significantly higher diversity than wet season and the railway site had higher diversity than the other infrastructure. The intermediate plots (500 m from infrastructure) had significantly higher abundance of animals than immediate (0-50 m) and distant (1000 m) plots. The differences in these results can be attributed by seasonal fluctuations of animal populations, and intensity of disturbance in each infrastructure and plot. It is important to examine impacts of future infrastructure developments using small mammals.