DIVING PATTERNS OF CALIFORNIA SEA LIONS, ZALOPHUS-CALIFORNIANUS
DIVING PATTERNS OF CALIFORNIA SEA LIONS, ZALOPHUS-CALIFORNIANUS
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DOI：
10.1139/z89-129
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发表时间：
1989-04-01
影响因子：
1.4
通讯作者：
ANTONELIS, GA
中科院分区：
文献类型：
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作者：
FELDKAMP, SD;DELONG, RL;ANTONELIS, GA
1982年和1983年在加州圣米格尔岛的夏季繁殖季节，用时间-深度记录仪对10只成年雌性加州海狮（Zalophus californianus）的潜水模式进行了研究。在17次喂食旅行，代表40.6天在海上，动物超过8900潜水，其中最深的估计在274米，而最长的是9.9分钟。大多数潜水，但是，持续时间不到3分钟，深度80米。从估计的身体氧气储存，我们预测，潜水至5.8分钟，可以支持有氧。因此，成本效益的考虑，基于猎物的可用性和遭遇率可能比生理限制更重要的是在塑造觅食模式的Zalophus。海狮几乎在整个海上活动，在平均行程中只有3%的时间在水面上休息。高峰潜水频率出现在黄昏时分接近日出和日落。然而，在一天的所有时间内，潜水是频繁的，并且通常聚集成持续平均（. ±.）SD）为3.3 . ±-。1.5 H.我们认为，这些回合代表离散猎物补丁上的积极喂养。在短时间的比赛中（< 3小时），潜水深度的变化比比赛之间发生的潜水要小。在较长时间的较量中，潜水深度的变化与追逐垂直迁移的猎物的方式一致。在1983年厄尔尼诺现象期间，海狮通过延长潜水时间来弥补食物供应的减少。这些季节性和昼夜变化的潜水模式表明，猎物遇到的速度强烈影响个人潜水的深度和持续时间。
The diving patterns of 10 adult female California sea lions (Zalophus californianus) were examined during the summer breeding season on San Miguel Island, California, in 1982 and 1983 using time-depth recorders. During 17 feeding trips, representing 40.6 days at sea, animals made over 8900 dives, the deepest of which are estimated at 274 m, while the longest was 9.9 min. The majority of dives, however, were less than 3 min in duration and 80 m in depth. From estimates of body oxygen stores, we predict that dives up to 5.8 min can be supported aerobically. Therefore, cost-benefit considerations based on prey availability and encounter rate may be more important than physiological limits in shaping the foraging patterns of Zalophus. Sea lions were active virtually throughout their time at sea, resting on the surface for only 3% of the average trip. Peak diving frequency occurred during the twilight hours near sunrise and sunset. Dives were frequent, however, during all hours of the day and were typically clustered into bouts that lasted a mean (.+-. SD) of 3.3 .+-. 1.5 h. We suggest that these bouts represent active feeding on discrete prey patches. During short bouts (< 3 h), dive depth was less variable than for dives occurring between bouts. During longer bouts, dive depth changed in a manner consistent with pursuit of vertically migrating prey. During the 1983 El Nino, sea lions compensated for a reduction in food availability by lengthening dive bouts. These seasonal and diel variations in diving patterns suggest that the rate of prey encounter strongly influences the depth and duration of individual dives.