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This study aimed to analyze spatio-temporal changes in habitat quality in Guizhou Province during the 1990–2018 period and identify factors influencing habitat quality. Land-use data for the period were used to evaluate spatio-temporal variations in habitat quality using the InVEST model, and factors influencing habitat quality were analyzed using GeoDetector. According to the results, cultivated land and forestland decreased by 0.48% and 0.88%, respectively, during the study period. Grassland, water, and construction land areas increased, with construction land increasing the most (0.92%) followed by water area (0.37%). The main land-use changes included conversion of cultivated land to forestland, grassland, and construction land. The average habitat quality index for Guizhou Province changed from 0.633 to 0.627 over the 1990–2018 period, showing an overall downward trend. The distribution pattern of habitat quality was spatially "high in the north, south, and, east, and low in the west". The most significant improvement of habitat quality was in the western region, whereas the most significant decline of habitat quality was in the central region. Land-use was the major factor influencing the spatio-temporal variations in habitat quality, and the interactive effect between any two factors was stronger than that of a single factor. Natural factors and human factors co-dominated the temporal-spatial changes in habitat quality. [ABSTRACT FROM AUTHOR]

Several overwintering crane species like Black-necked cranes (Grus nigricollis) mainly depends on wetlands for foraging or roosting, preferring stable water depths. Understating the wading depths of cranes is a pressing concern for the better management of wetlands and robust conservation of the overwintering cranes populations. Yet, practically it is very difficult to precisely measure the wading depths due to several limitations like, inaccessibility and sampling difficulties. In the current study a sample of 1288 wading photographs of cranes, based on the constancy of proportion of tibiotarsus to tarsometatarsus was taken in Caohai wetland situated in the Northwest Guizhou Province of southwest China. Caohai Wetland is the biggest overwintering wetland around the world, and a very promising area to infer the exact ranges of wading depths of these cranes. The ratio of tibiotarsus to tarsometatarsus of the cranes standing on the lands and the ratio of tibiotarsus to the rest of tarsometatarsus of the cranes standing in water were measured; to infer the projection depths of the part of tarsometatarsus submerged in water, which was used to calculate the accurate depth range of the cranes by comparing with the referenced values. According to the results, 89.92% of individuals preferred the water depths from (0–20] cm, 76.11% preferred (0–10] cm% while water depths for 49.04% individuals was (0–5] cm. Thus we conclude that the Black-necked Cranes prefer a depth range of (0–10] cm. This water depth may be relative to the swamps around the lake, which are very important foraging and roosting sites for cranes, For better habitat management, we strongly recommend paying special attention to swamps with specific water depth ranges, particularly when the water level changes. [ABSTRACT FROM AUTHOR]

Background: Understanding how overwintering birds choose foraging habitats is very important for conservation management. The overwintering Black-necked Crane (Grus nigricollis) feeds on crop remains in farmlands; thus, reasonable conservation management of this type of farmland that surrounds wetlands is critical for the overwintering populations of the Black-necked Crane; however, it is not clear how the Black-necked Crane chooses the foraging land in the farmland. Methods: A thorough field positioning survey of all foraging sites in farmland areas around the Caohai Wetland and a sampling analysis of habitat selection by the Black-necked Crane were conducted during the winters from 2016‒2017 and 2017‒2018. Results: Multiple factors contributed to the selection of foraging habitat in farmlands, i.e., food factors (crop remains and tillage methods) > human disturbance factors (distance to road and settlement) > topography factors (slope aspect), listed according to the strength of influence. Additionally, Black-necked Cranes tend to choose farmland sites where there was no machine tillage, the crop remains were > 500 g/m2, the distance to residences ranged from 100 to 500 m, the distance to roads ranged from 50 to 100 m, and the slopes exhibited western or eastern aspects. As the winters progressed, the volume of the edible crop remains declined, and the influences of the other main factors also changed, i.e., the factors of human disturbance (distance to road and settlement) became less important, while the effect of the food factor (crop remains) was strengthened. Thus, the foraging sites near the road became more important. Conclusion: The farming area surrounding the Caohai Wetland is very important for the overwintering Black-necked Crane. Food factors and human disturbance factors are the main factors that influence the choice of feeding ground. [ABSTRACT FROM AUTHOR]

Correction to: I Scientific Reports i https://doi.org/10.1038/s41598-023-33903-8, published online 27 April 2023 The original version of this Article contained an error in the Abstract. "High habitat quality areas were mainly located in the western part of Guizhou Province, whereas low habitat quality areas were located in the central region." now reads: "The most significant improvement of habitat quality was in the western region, whereas the most significant decline of habitat quality was in the central region.". [Extracted from the article]