Autumn migration of black-necked cranes on the Qinghai-Tibetan and Yunnan-Guizhou Plateaus
Data files
Sep 07, 2024 version files 155 KB
-
Metadata.csv
-
README.md
Abstract
Despite previous research efforts, the majority of migration routes of the black-necked cranes (Grus nigricollis) have remained veiled. In this study, we utilized satellite telemetry data from 45 cranes between 2015 and 2021 to unveil critical insights. Our results revealed 11 distinct autumn migration routes and one sedentary flock, of which eight routes and the sedentary flock were previously undocumented. Our findings highlighted the remarkable diversity in the migration routes of black-necked cranes, especially in terms of migration orientations, spatial-temporal patterns, and altitudinal movement patterns. Cranes breeding on the eastern, northern, and central Qinghai-Tibetan Plateau migrated southward, while those on the northern slopes of the Himalayas migrated eastward, westward, northward, or opted to remain sedentary. Moreover, we expanded the known range of migration distances to 84–1,520 km at both ends (excluding sedentary individuals) and identified two long-term (Da Qaidam and Chaka) and one short-term (Gyatong grassland) stopover sites. Furthermore, our study revealed that the breeding colonies in the Qilian Mountains on the northeastern Qinghai-Tibetan Plateau utilized long-term stopover sites before embarking on significant altitude ascent, while other flocks displayed more urgent migration patterns, preferring to roost only at night. By unveiling the near-complete autumn migration routes of black-necked cranes, our research has contributed to discovering the critical habitats and connectivity among various breeding colonies, which is instrumental in developing effective seasonal conservation plans.
README: Title of Dataset: Autumn Migration of Black-necked Crane (Grus nigricollis) on the Qinghai-Tibetan and Yunnan-Guizhou Plateaus
Despite previous research efforts, the majority migration routes of the black-necked cranes (Grus nigricollis) have remained veiled. In this study, we utilized satellite telemetry data from 45 cranes between 2015 and 2021 to unveil critical insights. Our results revealed 11 distinct autumn migration routes and one sedentary flock, of which eight routes and the sedentary flock were previously undocumented. Our findings highlighted the remarkable diversity in the migration routes of black-necked cranes, especially in terms of migration orientations, spatial-temporal patterns, and altitudinal movement patterns.
Description of the Data and file structure
Data were received hourly via the Global System for Mobile Communications/GSM (CMCC, China). The tracking data was classified into six accuracy grades: A (5 m), B (10 m), C (20 m), D (100 m), E (200 m), and invalid. We analyzed the data using locations categorized as A, B, C, and D.
We calculated the migration distance, linear distance, and maximum step length via the great circle route using the “geosphere” and “move” packages in R v.4.2.1. The migration routes were mapped in QGIS v.3.24.1. We extracted the ground elevation using latitude and longitude data, calculated the average breeding elevation, average wintering elevation, and the elevation difference between breeding and wintering sites, andcompared the ground elevation of different routes in the migratory flight. The migration distance finished (%) for each point was calculated as the percentage of its respective migration distance to the overall migration distance. We plotted the ground elevation trends of different routes at the migration distance finished scales, using the smoothing-fitting method known as locally weighted regression (LOESS) from the ggplot2 package in R v.4.2.1.