Seasonal body mass changes in Eurasian Golden Plovers Pluvialis apricaria staging in the Netherlands:: decline in late autumn mass peak correlates with increase in raptor numbers
Seasonal body mass changes in Eurasian Golden Plovers Pluvialis apricaria staging in the Netherlands:: decline in late autumn mass peak correlates with increase in raptor numbers
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DOI：
10.1046/j.1474-919x.2003.00178.x
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发表时间：
2003-10-01
期刊：
影响因子：
2.1
通讯作者：
Jukema, J
中科院分区：
文献类型：
--
作者：
Piersma, T;Koolhaas, A;Jukema, J
在荷兰非繁殖季节，欧亚雨生美洲斑潜蝇的体重表现出惊人的季节性变化，第一个质量高峰在11月下旬和12月，第二个峰值在4月下旬和5月。尽管样本量很大，但这种模式在20世纪90年代的连续几年和不同年龄段之间的变化很小。然而，与一年中其他时间的身体质量水平形成对比的是，从20世纪70年代/80年代初到1989-2000年，金犁鱼的冬季峰值质量明显下降。平均减少了29克，大约是以前秋季储存的额外质量的一半。众所周知，这种额外的质量是由脂肪组成的，可以被解释为一种能量储存-保险-当负能量平衡迫使鸟类向南移动并停留在霜冻线之前时，突然的寒冷时期。由于9月至10月的大规模增长速度从20世纪80年代到90年代没有变化，粮食供应的变化不太可能解释长期的大规模下降。此外，已知的影响能量消耗和摄食率的两个因素--气温和降雨量--也没有差异。与犁鸟有关的一个显著环境变化是1980年代荷兰北部猛禽的数量急剧增加，特别是游隼、猎鹰和苍鹰Accipter Gentilis。我们认为，冬季种群峰值在十年内减半符合这样的假设，即在捕食风险增加的情况下，鸟类为了减少个体的脆弱性而降低它们的体重，这种减少可能会与饥饿风险的增加相权衡。
Eurasian Golden Plovers Pluvialis apricaria staging in the Netherlands during the non-breeding season show strikingly constant seasonal changes in body mass with a first mass peak in late November and December and a second peak in late April and May. Despite huge sample sizes, variations in this pattern over successive years in the 1990s and among age classes were minuscule. However, in contrast to the body mass levels at other times of the year, there was a marked decline in the winter peak mass of Golden Plovers from the 1970s/early 1980s to 1989-2000. The decrease, by an average of 29 g, was about half the extra mass previously stored in autumn. This additional mass is known to consist of fat and may be interpreted as an energy store-insurance-for sudden cold spells when a negative energy balance forces the birds to move south and stay in front of the frostline. As the rate of the mass increase in September-October showed no change from the 1980s to the 1990s, changes in food availability are unlikely to explain the long-term mass decline. Also, there were no differences in two factors known to influence energy expenditure and feeding rate, air temperature and rainfall. The one striking environmental change relevant to plovers was the steep increase in the occurrence of raptors in the northern Netherlands in the 1980s, notably Peregrine Falcons Falco peregrinus and Goshawks Accipter gentilis. We argue that the halving of the winter mass peak over a decade is consistent with the hypothesis that under increased risk of predation, birds lower their body mass in order to reduce individual vulnerability, a reduction that may be traded off against an increased risk of starvation.