Siberian Cranes are the most highly specialized members of the crane family in terms of habitat requirements, morphology, vocalizations, and behavior. This critically endangered species is now found in only two populations: eastern and western. A central population of Siberian Cranes once nested in western Siberia and wintered in India, but there is a high probability that this population has been recently extirpated. It has beenestimated that about 4000 SiberianCranes haveoverwinteredin Poyang Lake in recent years. This lake has been an important wintering site for the cranes.
From January to March, 2012, and from December 2012 to March 2013, we used instantaneous scanning sampling method to observe the wintering behavior of SiberianCraneswintering in the Poyang Lake National Nature Reserve, and we analyzed the effects of age, flock size, habitat, and weather on their wintering behavior. The results showed that the main behavioralhabits of the wintering cranes included feeding, vigilance, locomotion, grooming, resting, and hting. The cranes spent 81.1% of their daily time feeding, 13.1% being vigilant, 3.8% grooming, 1.7% in locomotion, 0.2% resting, and 0.1% fighting.The cranes showed a distinctive daily rhythm with feeding, locomotion, resting, and fighting, but no significant rhythm with vigilance and grooming behaviors. Feeding, locomotion, and fighting behaviors peakeddaily in the morning and afternoon, while resting behavior peaked in the middle of the day.
The proportion of time engaged in different behaviorsinthe wintering cranes was significantly influenced by age, flock size, weather, and habitat:the juveniles spent significantly more time feeding and less time being vigilant than the adults; flocks of cranes spent significantly more time feeding, significantly less time being vigilant, and significantly more time fighting than the individuals in a family; on sunny days, the cranes spent significantly more time being vigilant and less time feeding than on cloudy days; on windy days the cranes spentsignificantly more time grooming; and on foggy days the cranes spent significantly more time feeding and less time being vigilant. In grassland and shoal habitats,there was no significant difference between the timespent feeding and being vigilant, which may be correlated with the fact that both of these habitats were neighboring and the craneswere confronted with the same degree of human disturbance in both habitats. However, in grassland and shoal habitats there were significant differences in the time spent grooming and in locomotion. The results of a general linear model analysis revealed that, in terms of time spent engaged in different behaviors, there was a significant relationship between age and flock size, age and habitat, flock size and weather, flock size and habitat, and weather and habitat inSiberianCranes.