Habitat change has major effects on wildlife and it is important to understand how wild animals respond to changing habitats. Dashanbao National Nature Reserve, in north-east Yunnan, China, which was established for the protection of the black-necked craneGrus nigricollis, other wintering waterbirds and the upland wetland ecosystem, recently began converting farmland to grassland and woodland. With respect to this policy we studied habitat selection by black-necked cranes in the Reserve from November 2006 to April 2007. Farmland, grassland, marsh and water were used by black-necked cranes but no cranes occurred in man-made woodland. Black-necked cranes showed the least preference for grassland and no significant differences were detected in the species’ preference for the other three habitats. However, black-necked cranes exhibited different behavioural responses to the four habitats: farmland and grassland were their main foraging sites. Principle component analysis verified that a foraging-related component was the first factor determining habitat selection. Cranes used habitat close to their roosts with short grass, shallow water and less disturbance by human activity. Our results indicate that the policy of converting farmland and grassland to woodland is not beneficial for conservation of the crane. For effective conservation of the black-necked crane scientific habitat management that takes into account habitat selection by the species is required, with the retention of some farmland and restoration of wetlands.

Understanding the habitat use and spatial distribution of wildlife can help conservationists determine high-priority areas and enhance conservation efforts. We studied the wintering habitat use, preference, and utilization distribution of two crane species, that is, the black-necked crane (Grus nigricollis, Przevalski, 1876) and common crane (Grus grus, Linnaeus, 1758), in Huize National Natural Reserve, Yunnan–Guizhou Plateau, southwestern China. Line transects indicated that anthropogenic farmland habitat was highly utilized and was positively selected by both crane species (>90% of flocks observed for both species). Black-necked cranes preferred marshland in spring (February and March) but avoided grassland during the entire wintering period, whereas common cranes avoided both marshland and grassland throughout the entire period. The two cranes species had communal nightly roosting sites and separate daily foraging sites. Black-necked cranes were distributed within two km (1.89 ± 0.08 km) of the roosting site, covering an area of 283.84 ha, with the core distribution area encompassing less than 100 ha. In contrast, common cranes were distributed far from the roosting site (4.38 ± 0.11 km), covering an area of 558.73 ha, with the core distribution area encompassing 224.81 ha. Thus, interspecies competition may have influenced the habitat preference and spatial distribution divergence of these two phylogenetically related species. This study should help guide habitat management as well as functional zoning development and adjustment in the future. Based on our results, we recommend restoration of additional wetlands, retention of large areas of farmland, and protection of areas that cranes use most frequently.

One of the most endangered populations of Black‐necked Cranes (Grus nigricollis), the central population, is declining due to habitat loss and degradation, but little is known about their space use patterns and habitat preferences. We examined the space use and habitat preferences of Black‐necked Cranes during the winter of 2007–2008 at the Napahai wetland in northwest Yunnan, China, where approximately 300 Black‐necked Cranes (>90% of the total central population) spent the winter. Euclidean distance analysis was employed to determine the habitat preferences of Black‐necked Cranes, and a local nearest‐neighbor, convex‐hull construction method was used to examine space use. Our results indicate that Black‐necked Cranes preferred shallow marsh and wet meadow habitats and avoided farmland and dry grassland. Core‐use areas (50% isopleths) and total‐use areas (100% isopleths) accounted for only 1.2% and 28.2% of the study area, respectively. We recommend that habitat protection efforts focus on shallow marsh and wet meadow habitats to maintain preferred foraging sites. Core‐use areas, such as the primary foraging areas of Black‐necked Cranes, should be designated as part of the core zone of the nature reserve. Monthly shifts in the core‐use areas of the cranes also indicate that the reserve should be large enough to permit changes in space use. In addition to preserving habitat, government officials should also take measures to decrease human activity in areas used by foraging Black‐necked Cranes.

We equipped five Black-necked Cranes (Grus nigricollis) with satellite transmitters between February and November 2009 to investigate their migration routes between breeding areas and wintering area at Napahai Marsh (3,260 m asl), China. We identified the Shaluli Mountain region (southwest Sichuan), including Daocheng, Litang, Baiyu, and Xinlong counties as a new breeding area with a mean elevation of 4,330 m asl. Four of five tracked cranes spent the summer in Daocheng County. The fifth crane was there briefly and then moved north to Baiyu and Xinlong counties. The distance between Napahai Marsh and Daocheng County (∼180 km) is one of the shortest migration routes among crane species, but covered an elevation increase of ∼1,200 m. The migration route of the fifth crane was ∼400 km in length and occurred over 2 or 5 days in spring 2009 and 2010, respectively, and 19 days in fall 2009 with five stopovers.

It is prevalent to use ecological niche models in the analysis of species expansion and niche changes. However, it is difficult to estimate the niche when alien species fail to establish in exotic areas. Here, we applied the tolerance niche concept, which means that niche of species can live and grow but preclude a species from establishing self‐sustaining populations, in such fail‐to‐establish events. Taking the rapidly expanded bird, Asian openbill (Anastomus oscitans), as a model species, we investigated niche dynamics and its potential effects on the population by Niche A and ecospat, predicted potential distribution by biomod2. Results showed that niche expansion has occurred in two non‐native populations caused by the tolerance of colder and wetter environments, and potential distribution mainly concentrated on equatorial islands. Our study suggested that the expanded niche belongs to tolerance niche concept according to the populations' dynamics and GPS tracking evidence. It is essential to consider source populations when we analyze the alien species. We recommended more consideration to the application of tolerance niche in alien species research, and there is still a need for standard measurement frameworks for analyzing the tolerance niche.

The seasonal migration of wild aquatic birds plays a critical role in the maintenance, transmission, and incursion of the avian influenza virus (AIV). AIV surveillance was performed during 2020–2021 in two national nature reserves with abundant wild bird resources in Yunnan, China. Four H5N8 AIVs isolates from the common crane were identified by next-generation sequencing. Phylogenetic analysis demonstrated that all eight gene segments of these H5N8 AIVs belonged to clade 2.3.4.4b high-pathogenic AIV (HPAIV) and shared high nucleotide sequence similarity with the strains isolated in Hubei, China, and Siberia, Russia, in 2020–2021. The H5N8 HPAIVs from common cranes were characterized by both human and avian dual-receptor specificity in the hemagglutinin (HA) protein. Moreover, possessing the substitutions contributes to overcoming transmission barriers of mammalian hosts in polymerase basic 2 (PB2), polymerase basic protein 1 (PB1), and polymerase acid (PA), and exhibiting the long stalk in the neck region of the neuraminidase (NA) protein contributes to adaptation in wild birds. Monitoring AIVs in migratory birds, at stopover sites and in their primary habitats, i.e., breeding or wintering grounds, could provide insight into potential zoonosis caused by AIVs.