Montane ecosystems contribute greatly to global diversity, serving as refuges for numerous species, many of which are found exclusively in mountainous regions. These species are particularly vulnerable to anthropogenic pressures, which are expected to drive heterogeneous shifts in elevational distributions and potentially lead to range restrictions. Here, we resurveyed the elevational ranges of birds in Tianmu Mountain of eastern China in 2021, 60 years after the original survey conducted in the 1960s. We aimed to assess whether elevational shifting trends in lowland and highland bird assemblages are asynchronous and whether biotic (e.g., species traits) and abiotic (temperature and relative humidity) factors can predict these trends. Over the past 60 years, we observed the upward shift in the upper limit of lowland birds, resulting in range expansion. In contrast, highland birds have generally shifted their upper limits downward, leading to range contraction. Upslope shifts and range expansions were more pronounced in species with smaller range sizes, while widely distributed species were more likely to move downward and lose occupancy of elevational areas. Our findings reveal contrasting elevational range shifts between lowland and highland bird assemblages. This pattern suggests that recent avian redistribution in Tianmu Mountain was shaped by local hydrothermal conditions and species identity rather than by upslope tracking of climate warming. These results highlight the need for caution when applying the conventional expectation of upslope shifts to species redistribution in montane ecosystems.