年龄、集群、生境及天气对鄱阳湖白鹤越冬期日间行为模式的影响

于2012年1—3月和2012年12—2013年3月,采用瞬时扫描法研究了鄱阳湖国家级自然保护区越冬白鹤(Grusleucogeranus)的昼间时间分配模式和日活动节律,分析了年龄、集群大小、生境类型和天气对白鹤越冬行为的影响。结果表明,白鹤越冬期的主要行为有觅食、警戒、理羽、游走、休息和争斗。其中,觅食是鄱阳湖越冬白鹤主要行为,占其昼间活动时间的82.94%;警戒占11.94%,理羽占3.52%,游走占1.88%,休息占0.15%,争斗占0.02%。白鹤在越冬期间的觅食、游走、休息和争斗行为存在明显的昼间节律性,其中游走、觅食和争斗行为在每天的上午和下午各存在1个高峰,休息行为在中午出现一个高峰;警戒和理羽行为则没有显著的昼间节律变化。年龄、集群大小、天气和生境对白鹤的越冬行为具有显著的影响:幼鹤取食的时间显著多于成鹤,而警戒时间则显著的小于成鹤;与家庭群中的个体相比,集体群中的个体取食和争斗时间显著增加,警戒时间显著减少;在天气晴朗时,白鹤的警戒时间显著大于阴天的警戒时间,取食时间则显著少于阴天时白鹤的取食时间;白鹤在大风天气显著增加理羽行为;在有雾的天气会显著增加取食时间,减少警戒时间。在草洲和浅水两种生境中,白鹤的游走和理羽行为存在显著差异,而觅食和警戒行为没有显著的差异,这可能源于草洲和浅水生境相互毗邻,并且具有相同程度的人为干扰。GLM分析结果表明,年龄和集群大小、年龄和生境、集群大小和天气、集群大小和生境、天气和生境对白鹤昼间时间分配模式的影响存在显著交互效应。

The influence of age, flock size, habitat, and weather on the time budget and the daily rhythm of wintering Siberian Cranes in Poyang Lake

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.