Blomqvist Sven, Holmgren Noél, Åkesson Susanne, Hedenström Anders, Pettersson Jan
Department of Systems Ecology, Stockholm University, 106 91, Stockholm, Sweden.
Department of Natural Sciences, University of Skövde, P.O. Box 408, 541 28, Skövde, Sweden.
Oecologia. 2002 Oct;133(2):146-158. doi: 10.1007/s00442-002-1017-2. Epub 2002 Oct 1.
The bird-lemming hypothesis postulates that breeding success of tundra-nesting geese and waders in Siberia follows the cyclic pattern of lemming populations, as a result of predators switching from lemmings to birds when the lemming population crashes. We present 50 years of data on constant-effort catches of red knot Calidris canutus and curlew sandpiper C. ferruginea at an autumn migratory stopover site (Ottenby) at the Baltic Sea, supplemented with literature data on winter censuses of dark-bellied brent goose Branta b. bernicla and white-fronted goose Anser albifrons in northwestern Europe, and waders in Germany and Southern Africa. Number and proportion of juveniles in these bird populations (both our own and literature data) were compared with an index of predation pressure (calculated from the abundance of lemmings on the Taimyr peninsula), and climate indices for the North Eurasia and the North Atlantic regions. The index of predation pressure correlated significantly with the number of juveniles of red knot and curlew sandpiper, but not with number of adults. Also, this index correlated with the reproductive performance of geese and waders reported in the literature. Fourier analysis revealed a significant deviation from random noise with the maximum spectral density at the period length of 3 years for number of juvenile red knots and curlew sandpipers captured at Ottenby, abundance of lemmings, reproduction in arctic fox Alopex lagopus, and reproductive performance in geese on the Siberian tundra. Also, the date of passage at Ottenby for adult red knot and curlew sandpiper showed a spectral density peak at a period length of 3 years, the latter species also showing a peak at a period length of 5-6 years. Passage dates for adult red knot and curlew sandpiper were earlier in years of high predation pressure compared with years of low predation pressure. The fluctuations in reproductive success of the studied Siberian goose and wader species appear to be primarily influenced by biotic factors in the breeding area, rather than by abiotic factors, such as climate oscillations. Annual variations in migratory arctic bird populations may have far reaching effects in habitats along their migration routes and in their wintering areas. We suggest a link between lemming cyclicity in the Northern Hemisphere and predation pressure on Southern Hemisphere benthos, in which the signal is carried between continents by long distance migrating waders.
鸟类 - 旅鼠假说假定，由于在旅鼠数量锐减时捕食者从旅鼠转向鸟类，西伯利亚苔原筑巢的鹅和涉禽的繁殖成功率遵循旅鼠种群的周期性模式。我们展示了在波罗的海一个秋季迁徙中途停歇地（奥特恩比）对红腹滨鹬和弯嘴滨鹬进行持续努力捕获的50年数据，并补充了关于欧洲西北部黑腹 Brent 鹅、白额雁以及德国和南部非洲涉禽冬季数量普查的文献数据。将这些鸟类种群中幼鸟的数量和比例（包括我们自己的数据和文献数据）与捕食压力指数（根据泰梅尔半岛旅鼠的数量计算得出）以及欧亚大陆北部和北大西洋地区的气候指数进行了比较。捕食压力指数与红腹滨鹬和弯嘴滨鹬幼鸟的数量显著相关，但与成鸟数量无关。此外，该指数与文献中报道的鹅和涉禽的繁殖表现相关。傅里叶分析表明，在奥特恩比捕获的幼鸟红腹滨鹬和弯嘴滨鹬数量、旅鼠数量、北极狐繁殖情况以及西伯利亚苔原鹅的繁殖表现，在周期长度为3年时，与随机噪声存在显著偏差，且具有最大谱密度。此外，成年红腹滨鹬和弯嘴滨鹬在奥特恩比的通过日期在周期长度为3年时出现谱密度峰值，后者在周期长度为5 - 6年时也出现峰值。与捕食压力低的年份相比，成年红腹滨鹬和弯嘴滨鹬在捕食压力高的年份通过日期更早。所研究的西伯利亚鹅和涉禽物种繁殖成功率的波动似乎主要受繁殖地的生物因素影响，而非气候振荡等非生物因素。北极候鸟种群的年度变化可能对其迁徙路线沿线和越冬地的栖息地产生深远影响。我们提出北半球旅鼠的周期性与南半球底栖生物捕食压力之间存在联系，其中信号通过长距离迁徙的涉禽在各大洲之间传递。
