Satellite Tracking Likely Reveals a New Subpopulation of Bar-Headed Geese Anser indicus in Qinghai-Tibet Plateau, China

Unlike the well-documented eight subpopulations of Bar-headed Geese (Anser indicus), no studies of long-term number changes and tracking have been conducted for those breeding at Bande Lake, one important breeding site on the Qinghai-Tibet Plateau. Between 2012 and 2023, we surveyed the number of Bar-headed Geese at Bande Lake and tracked 14 individuals to identify their migration routes and patterns. Our results revealed a remarkable 512% increase in the number of geese from 1,172 to 7,742 over the past 12 years. Satellite tracking highlighted a distinct migration route and pattern with departing from breeding sites on 16 October (± 7 day), stopover in the Qiangtang Lakes for 11 ± 8 days, and arrival at the YarlungZangbo River Basin for wintering on 30 October (± 13 day). The migration covered a relatively short distance of 662 ± 77 km and lasted approximately 14.6 ± 6.7 days. The unique migration pattern and increasing breeding size suggests that the Bar-headed Geese breeding in Bande Lake represent a growing subpopulation distinct from other subpopulations. Giving their extended summering/wintering duration and significant population size, targeted conservation efforts remain critical for both Bande Lake and the Yarlung Tsangpo River Basin.