Temporal changes in Weddell seal dive behavior over winter: Are females increasing foraging effort to support gestation?
Temporal changes in Weddell seal dive behavior over winter: Are females increasing foraging effort to support gestation?
复制标题
威德尔海豹冬季潜水行为的时间变化：雌性是否会增加觅食努力以支持妊娠？
DOI：
10.1002/ece3.4643
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发表时间：
2018
影响因子：
2.6
通讯作者：
Burns, Jennifer M.
中科院分区：
文献类型：
--
作者：
Shero, Michelle R.;Goetz, Kimberly T.;Costa, Daniel P.;Burns, Jennifer M.
在资本繁殖的海洋哺乳动物中，在与妊娠相吻合的觅食旅行期间捕获的猎物必须提供能量以满足成长中的胎儿的即时需求，并为满足随后的哺乳需求提供储备。威德尔海豹（Leptonychotes weddellii）在妊娠期（冬季）觅食期后分娩，与未能分娩的雌性相比，获得相似的质量和脂质比例。因此，觅食行为的任何变化都可以归因于妊娠成本。为了研究与成功繁殖相关的觅食努力的差异，在罗斯海的蜕皮后雌性威德尔海豹上部署了23个卫星标签。在第二年返回该地区的20只雌性中，有12只雌性分娩，8只没有分娩。与非繁殖海豹相比，第二年分娩的雌性海豹开始了冬季觅食期，潜水时间更长，深度更深。在冬季中期到后期，繁殖雌性在一天中潜水的比例显着增加，并且降低了它们的潜水代谢率（DMR），或者比没有幼崽的雌性更频繁地超过了计算的有氧潜水极限（cADL）。此外，非生殖雌性平均每天组织2-3次短时间潜水（BOUT短; 7.06 ± 1.29小时;平均值± 95% CI），而生殖雌性每天进行1-2次BOUT短时间潜水（10.9 ± 2.84小时），包括一次无休息的每日长时间觅食。在计算的DMR中，潜水活动预算和抑郁的增加幅度与估计的支持胎儿的能量需求密切匹配。这项研究是第一个确定增加觅食的努力，与成功繁殖的顶级捕食者，并表明，生殖女性必须更接近他们的生理极限，以支持妊娠成本。
In capital‐breeding marine mammals, prey acquisition during the foraging trip coinciding with gestation must provide energy to meet the immediate needs of the growing fetus and also a store to meet the subsequent demands of lactation. Weddell seals (Leptonychotes weddellii) that give birth following the gestational (winter) foraging period gain similar proportions of mass and lipid as compared to females that fail to give birth. Therefore, any changes in foraging behavior can be attributed to gestational costs. To investigate differences in foraging effort associated with successful reproduction, twenty‐three satellite tags were deployed on post‐molt female Weddell seals in the Ross Sea. Of the 20 females that returned to the area the following year, 12 females gave birth and eight did not. Females that gave birth the following year began the winter foraging period with significantly longer and deeper dives, as compared to non‐reproductive seals. Mid‐ to late winter, reproductive females spent a significantly greater proportion of the day diving, and either depressed their diving metabolic rates (DMR), or exceeded their calculated aerobic dive limit (cADL) more frequently than females that returned without a pup. Moreover, non‐reproductive females organized their dives into 2–3 short bouts per day on average (BOUTshort; 7.06 ± 1.29 hr; mean ± 95% CI), whereas reproductive females made 1–2 BOUTshortper day (10.9 ± 2.84 hr), comprising one long daily foraging bout without rest. The magnitude of the increase in dive activity budgets and depression in calculated DMR closely matched the estimated energetic requirements of supporting a fetus. This study is one of the first to identify increases in foraging effort that are associated with successful reproduction in a top predator and indicates that reproductive females must operate closer to their physiological limits to support gestational costs.