DIEL VARIATION IN MIGRATION RATES OF EASTERN PACIFIC GRAY WHALES MEASURED WITH THERMAL IMAGING SENSORS
DIEL VARIATION IN MIGRATION RATES OF EASTERN PACIFIC GRAY WHALES MEASURED WITH THERMAL IMAGING SENSORS
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用热成像传感器测量东太平洋灰鲸迁徙速度的昼夜变化
DOI：
10.1111/j.1748-7692.1999.tb00811.x
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发表时间：
1999
影响因子：
2.3
通讯作者：
T. E. Martin
中科院分区：
文献类型：
--
作者：
W. Perryman;M. A. Donahue;J. Laake;T. E. Martin
1994年、1995年和1996年1月，灰鲸向南迁徙经过加州中部时，我们用热成像传感器记录了它们的撞击。为了我们的采样目的，我们定义了白天（0730-1630）和夜晚（1630-0730），以与同时进行的目视计数的开启关闭努力期相一致。我们汇总了三年的采样数据，并通过比较在各自的24小时内收集的样本的配对日/夜平均值，测试了浮出水面间隔，豆荚大小，离岸距离，迁移率和游泳速度的昼夜变化。我们使用整个迁移期的数据进行了这些测试，然后对大约中位迁移日期（1月15日）之前和之后收集的样本进行了重复测试。在整个迁移期间，我们观察到较大的昼夜豆荚大小= 1.75？0.280，i&hr = 1.63 2 0.232）和较大的昼夜离岸距离（*dAy = 2.30 t 0.328 km，fnIghr = 2.03？0.356 km），但在浮出间隔上没有发现昼夜变化。在整个迁移期间，夜间迁移率（每小时通过的鲸鱼平均数量）高于白天的迁移率。在迁移的前半段，我们没有发现豆荚大小或浮出水面间隔的昼夜变化，但昼夜离岸距离大于夜间= 2.28
We recorded the blows of gray whales during their southbound migration past central California in January 1994, 1995, and 1996, using thermal imaging sensors. For our sampling purposes, we defined day (0730-1630) and night (1630-0730) to coincide with the onloff effort periods of the visual counts being conducted concurrently. We pooled data across the three years of sampling and tested for diel variation in surfacing interval, pod size, offshore distance, migration rate, and swimming speed by comparing paired day/night means for samples collected within the respective 24-h period. We performed these tests using data from the entire migration period and then repeated the tests for samples collected prior to and after the approximate median migration date (15 January). Over the entire migration period we observed larger diurnal pod sizes = 1.75 ? 0.280, .i&hr = 1.63 2 0.232) and greater diurnal offshore distances (*dAy = 2.30 t 0.328 km, fnIghr = 2.03 ? 0.356 km) but found no diel variation in surfacing interval. For the entire migration period, the nocturnal migration rate (average number of whales passing per hour) was higher than the diurnal rate. During the first half of the migration we detected no diel variation in pod size or surfacing interval, but diurnal offshore distances were larger than at night = 2.28