INFLUENCES OF FOOD AVAILABILITY AND PREDATION ON SURVIVAL OF KITTIWAKES
INFLUENCES OF FOOD AVAILABILITY AND PREDATION ON SURVIVAL OF KITTIWAKES
复制标题
食物供应和捕食对三趾鸥生存的影响
DOI：
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发表时间：
2002
期刊：
影响因子：
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通讯作者：
R. Furness
中科院分区：
文献类型：
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作者：
D. Oro;R. Furness
生活史理论预测了当前繁殖和生存之间的权衡，以最大限度地保持健康。在长寿的海鸟中，当繁殖的环境条件不利时，人们可能会认为成年海鸟不会通过过度的繁殖投资来阻碍生存。一些环境因素降低了在英国设得兰繁殖的黑腿猫尾(Rissa Tridactyla)的繁殖力，这种集合种群在过去20年里大幅下降。提出了两个假设来解释这一下降：(1)自20世纪80年代末以来发生的桑迪尔(猫头鹰的主要猎物)的可获得性减少；(2)猫尾鸟的主要捕食者--大燕鸥的捕食增加。关于食物供应的详细数据(按年龄组划分的桑迪尔种群大小)，小猫的身体状况和繁殖成功，以及大蝎的饮食和生产力，使我们能够评估从1986年到1997年这些因素中的每一个对成年小猫存活的影响。建立了捕获-再捕获模型，以检验当地成虫存活率与环境参数之间的相关性。繁殖季节结束时的身体状况和0组(幼体？1岁)的可获得性对成鱼存活率有正向影响，而当大SKUA生产力高时成鱼存活率较低。成虫存活率在研究期间变化很大，从0.53±0.04到0.98±0.01(平均值+1 SD)，且与性别无关。这两种假设都得到了支持。与生活史理论的预测相反，在食物供应不足或捕食者活动频繁的年份，猫尾猫并没有停止繁殖，以不饲养幼崽为代价来缓冲自己的生存。虽然0组沙地可利用性影响小猫的繁殖成功率，但对成体存活的影响也是显著的。食物供应影响成鸟存活率的发现对渔业管理具有重要意义，以尽量减少对海鸟的影响。
Life history theory predicts a trade-off between current reproduction and survival to maximize fitness. In long-lived seabirds, one might expect adults not to jeop- ardize survival by excessive reproductive investment when environmental conditions for breeding are adverse. Some environmental factors have reduced the fecundity of Black- legged Kittiwakes (Rissa tridactyla) breeding in Shetland, UK, a metapopulation that has declined substantially during the last two decades. Two hypotheses are proposed to explain this decrease: (1) reduced availability of sandeels (the main prey for kittiwakes), which has occurred since the late 1980s; and (2) increased predation by Great Skuas (Catharacta skua), the main predator of kittiwakes. Detailed data on food supply (sandeel stock size, by age groups), kittiwake body condition and breeding success, and diet and productivity of Great Skuas allowed us to assess the influence of each of these factors on adult kittiwake survival from 1986 through 1997. Capture-recapture models were constructed to examine correlations between local adult survival rate and environmental parameters. Body condition at the end of the breeding season and availability of 0-group (juveniles ? 1 yr old) sandeels positively influenced adult survival, whereas survival was lower when Great Skua pro- ductivity was high. Adult survival varied greatly during the study, from 0.53 + 0.04 to 0.98 ? 0.01 (mean + 1 SD), and was independent of sex. Both hypotheses were supported. Contrary to predictions of life history theory, kittiwakes did not refrain from breeding in years of poor food supply or high predator activity to buffer their survival at the cost of not rearing chicks. Although 0-group sandeel availability affected breeding success of kittiwakes, its influence on adult survival was also significant. The discovery that food supply affects adult survival rate has important implications for fisheries management to minimize impacts on seabirds.