【摘要】 2016年12月—2017年2月和2017年12月—2018年1月,采用焦点动物法对鄱阳湖滨藕塘生境中白鹤(Grus leucogeranus)的取食行为进行观察,共记录921只次成鹤和547只次幼鹤的取食行为。结果表明,白鹤栖息水深为(17.29±8.75)cm(n=1468),取食水深为(18.84±10.32)cm(n=600),单次取食持续时间为(3.10±1.69)s(n=600),取食频次为(12.24±3.89)次/min(n=1012),取食成功频次为(1.78±1.59)次/min(n=1468),取食成功率为(16.26±14.41)%(n=1012)。成鹤取食成功频次(SymbolcA@~2=70.797,df=1,P=0.000)和取食成功率(SymbolcA@~2=5.356,df=1,P=0.020)均显著高于幼鹤,表明成鹤取食能力较幼鹤强,成鹤可以获得更多的能量。成鹤除维持自身能量支出外,还需要花费较多的能量用于辅食和警戒行为。成幼鹤的取食频次和单次取食持续时间无显著差异,这与成幼鹤的体型大小、能量需求和体内氧气储存量类似有关,也与多数研究认为幼鹤觅食经验不足,觅食成功率低,需要靠多次取食来补偿能量的观点不同。成鹤取食水深极显著高于幼鹤(SymbolcA@~2=50.945,df=1,P<0.0001),这可能与体型和取食经验有关。不同栖息水深下白鹤的取食成功率(SymbolcA@~2=15.297,df=4,P=0.004)和取食成功频次(SymbolcA@~2=23.155,df=4,P<0.0001)均存在极显著差异。不同时段的取食频次、取食成功频次和取食成功率均无显著差异,这可能与藕塘生境中白鹤采取触觉取食有关。此外,白鹤昼间取食行为无明显节律性,因此昼间能量需求相似,取食参数没有显著差异。更多还原

【Abstract】 Siberian Crane（Grus leucogeranus） is a large-sized, endangered waterbird, with about 95% of its global population（about 3500—4000 individuals） seasonally occurring in Poyang Lake, the largest freshwater lake in China. This species is listed in the First Category of National Key Protected Wildlife Species in China, and as critically endangered by the IUCN（International Union for Conservation of Nature）. Prior to 2010, the population of Siberian Cranes in China existed mainly within Poyanghu National Nature Reserve, with most cranes foraging in the natural habitat of Poyang Lake. However, an increasing number of cranes now forage in lotus ponds and rice fields that surround this lake; their distribution has also expanded into other nature reserves, such as Nanjishan Wetland National Nature Reserve. The numbers of these cranes in the lotus pond habitats can at times be more than 25%（about 1200 individuals） of the total global population. However, very less is known about the foraging strategies of the Siberian Crane in the lotus pond habitats. Here, we describe and compare the foraging behaviour of these cranes in the lotus ponds. Behaviour in lotus pond habitats differs from that in natural habitats, especially for foraging, vigilance, resting, and maintenance behaviours. Using focal animal observation methods, foraging behaviour of Siberian Cranes was observed between December 2016 and February 2017, and between December 2017 and January 2018. During these periods, observations of 921 individual-time adult cranes and 547 individual-time sub-adult cranes were made. The results show that the average water depth inhabited by Siberian Cranes is 17.29±8.75 cm（n=1468）, while the average depth in which they forage is 18.84±10.32 cm（n=600）. Foraging behaviour persisted for 3.10±1.69 s（n=600）, with mean foraging frequency of 12.24±3.89 times/min（n=1012）. Mean foraging success frequency and foraging success rate were 1.78±1.59 times/min（n=1468） and（16.26±14.41）%（n=1012）, respectively. Adult crane foraging success frequency(SymbolcA@² = 70.797, df=1, P=0.000) and foraging success rates(SymbolcA@² = 5.356, df=1, P=0.020) were both significantly higher than those of sub-adult cranes, indicating that adult cranes were more able to forage and could gain more energy. Adult cranes spent much energy on nurture and vigilance behaviour. No significant differences in foraging times and duration of foraging behaviour were apparent between adult and sub-adult cranes, which might be related to their similarity in body size, energy requirements, and oxygen storage capacity（in contrast to a theory that sub-adult cranes lack foraging experience, have low foraging success rates, and consequently have to forage more frequently to gain enough energy）. Water depths in which adult cranes forage are significantly greater than those in which sub-adult cranes forage(SymbolcA@² = 50.945, df=1, P=0.000), which might be related to body size and foraging experience. Extremely significant differences were observed in both foraging success frequency(SymbolcA@² = 15.297, df=4, P=0.004) and foraging success rates(SymbolcA@² = 23.155, df=4, P=0.000) for different water depths. However, no significant differences were observed in foraging frequency, foraging success frequency, and foraging success rates at different times, which might be related to the crane′s tactile feeding method. In addition, cranes had similar energy requirements and foraging parameters throughout the day, with no obvious foraging rhythm.更多还原