Constrained by available raptor hosts and islands: density-dependent reproductive success in red-breasted geese
Constrained by available raptor hosts and islands: density-dependent reproductive success in red-breasted geese
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受可用猛禽宿主和岛屿的限制：红胸雁的繁殖成功率取决于密度
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发表时间：
2003
期刊：
影响因子：
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通讯作者：
J. Quinn
中科院分区：
文献类型：
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作者：
J. Prop;J. Quinn
在本文中，我们的目的是解释分布的红胸鹅Branta ruficollis在不同的筑巢栖息地。为了远离陆地上的捕食者，红胸鹅的栖息地被限制在i）河流上的岛屿，ii）有游隼的悬崖，iii）靠近雪鸮和粗腿秃鹰的巢穴。多年来，巢址的可用性不同的猫头鹰和秃鹰的数量与旅鼠丰富的周期波动，但在研究地区发现的鹅巢总数没有变化。鹅的分布，结合繁殖成功的数据，提出了一个专制的机制：在悬崖上，鹅的数量是恒定的，每年都有很高的繁殖成功率，而在岛屿上，数量的大幅波动正好与成功率的相反趋势相吻合。显然，在这些猛禽缺席的年份里，与猫头鹰或秃鹰一起筑巢的鹅搬到了研究区域中存在的少数岛屿。因此，在这些年里，岛上鹅的平均密度是悬崖殖民地的两倍多（每公顷觅食栖息地分别为5.4和2.3对）。在悬崖上的群体规模可能受到鹅的领土行为的限制，尽管有证据表明，此外，宿主猎鹰也限制了筑巢鹅的数量。显然是罕见的密切相关的物种，我们观察到一个负面的密度依赖性效应的繁殖成功在巢期，并将其归因于有限的食物资源，加强了高频率的领土相互作用。这导致的结论是，除了捕食压力，筑巢密度是一个重要的代理商之间的联系旅鼠周期和鹅繁殖成功。
In this paper we aim to explain the distribution of red-breasted geese Branta ruficollis over different nesting habitats. To be safe from land predators red-breasted goose colonies were restricted to i) islands on rivers, ii) cliffs with peregrine falcons Falco peregrinus, and iii) the close proximity of snowy owl Nyctea scandiaca and rough-legged buzzard Buteo lagopus nests. Among years nest site availability varied by fluctuations in numbers of owls and buzzards in association with cycles in lemming abundance, but the total number of goose nests found in the study area did not vary. The distribution of geese, in combination with data on reproductive success, suggested a despotic mechanism: at cliffs, goose numbers were constant among years with an invariably high reproductive success, whereas large fluctuations in numbers on islands coincided with opposite trends in success. Apparently, geese nesting with owls or buzzards moved to the few islands present in the study area during years when these birds of prey were absent. Consequently, in such years the average density of geese on islands was more than twice as high as at cliff colonies (5.4 and 2.3 pairs per ha of foraging habitat, respectively). Colony size at cliffs may have been restricted by territorial behaviour of the geese, though there is evidence that, additionally, the host falcons also limited the number of nesting geese. Apparently rare in closely related species, we observed a negative density-dependent effect on reproductive success during the nest phase, and attribute this to limited food resources, reinforced by the high frequency of territorial interactions. This leads to the conclusion that, in addition to predation pressure, nesting density is an important agent in the link between lemming cycles and goose breeding success.