4 | Discussion
How small passerine birds adapt to winter is an important topic in
animal ecology and physiology. Our results provided the first detailed
group composition of orange-flanked bush-robins wintering in southwest
China and found that the number of 2yr+ adult males in bright-blue
plumages was significantly lower than the number of males in olive-brown
plumages. However, the sex-ratio was only slightly skewed to males among
robins with olive-brown plumages, suggesting the existence of habitat
sexual segregation. Additionally, our results revealed the factors that
may be influencing the daily body condition of each robin. Individual
robins can fine-tune their fat reserve in response to changes in weather
or food abundance. Interestingly, capturing birds may have a significant
positive effect on the birds’ fat reserve, in which a capture event
cuses the birds to store more fat.