Prey-dependent foraging tactics and prey profitability in a marine mammal
Prey-dependent foraging tactics and prey profitability in a marine mammal
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DOI：
10.3354/meps244235
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发表时间：
2002-01-01
影响因子：
2.5
通讯作者：
Marshall, GJ
中科院分区：
文献类型：
--
作者：
Bowen, WD;Tully, D;Marshall, GJ
捕食者面临着决定哪些猎物包括在他们的饮食，以最大限度地提高健身。用于捕获猎物的觅食策略和由此产生的猎物的盈利能力影响这些决定。我们提出了第一个证据的猎物依赖觅食策略和猎物的盈利能力在自由放养的鳍足类。我们研究了39个成年男性海豹Phoca vitulina在黑貂岛，新斯科舍省使用动物携带的视频系统。每个男性佩戴的摄像机系统为3天，在此期间，10分钟的视频样本记录每45分钟从06：00小时，导致约3小时的录像带每个男性和1094捕获尝试确定的猎物。雄性主要在沙矛Ammodytes和比目鱼（Pleuronectids）觅食，但偶尔也会追求鲑鱼和鳕鱼。觅食策略不同之间和猎物类型内的猎物行为的差异的基础上。沙矛既是一个神秘的猎物，当在底部基板，和一个明显的学校猎物。隐蔽型和显著型沙矛海豹的游泳速度、处理时间和捕获成功率存在差异。比目鱼的捕获成功率和处理时间最高。估计的盈利能力，即单位时间的净能量摄入量，也不同的猎物类型和猎物的大小。我们的研究结果表明，饮食选择可能有重要的意义上的觅食能量的鳍足类。
Predators face decisions about which prey to include in their diet in order to maximize fitness. The foraging tactics used to capture prey and the resulting profitability of prey influence these decisions. We present the first evidence of prey-dependent foraging tactics and prey profitability in a free-ranging pinniped. We studied 39 adult male harbour seals Phoca vitulina at Sable Island, Nova Scotia using an animal-borne video system. Each male wore the camera system for 3 d during which 10 min video samples were recorded every 45 min from 06:00 h, resulting in approximately 3 h of videotape per male and a total of 1094 capture attempts of identified prey. Males foraged mainly on sand lance Ammodytes dubius and flounders (Pleuronectids), but salmonid and gadoid fishes were occasionally pursued. Foraging tactics differed among and within prey types based on differences in prey behaviour. Sand lance was both a cryptic prey, when in the bottom substrate, and a conspicuous schooling prey. Seal swimming speed, handling time and capture success differed between cryptic and conspicuous sand lance. The highest capture success and handling time was recorded for flounders. Estimated profitability, i.e. net energy intake per unit time, also differed with prey type and prey size. Our results suggest that diet selection may have important implications on the foraging energetics of pinnipeds.