Sunrise nest attentiveness in cowbird hosts
Sunrise nest attentiveness in cowbird hosts
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牛鹂宿主的日出巢注意力
DOI：
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发表时间：
1994
期刊：
影响因子：
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通讯作者：
S. Sealy
中科院分区：
文献类型：
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作者：
D. L. Neudorf;S. Sealy
我们在日出前后记录了马尼托巴省三角洲沼泽寄生褐头牛鹂 (Molothrus ater) 10 个潜在宿主物种（牛鹂蛋的 6 个“接受者”和 4 个“拒绝者”）的 140 个巢穴的警惕性，以确定当牛鹂产蛋时宿主是否存在于巢穴上或巢穴附近。我们预测，在此期间，很少被寄生的受体物种会比被严重寄生的受体物种在巢穴中更加警惕。在我们的观察过程中，我们观察到了七次寄生行为，均发生在 03:44 CST（日出 44 分钟）和 4:00 CST（日出 25 分钟）之间。我们发现受体宿主的寄生频率与巢的注意力之间没有相关性。接受者和拒绝者在清晨警惕性方面没有显着差异。然而，所有栖息在巢中的雌性比不栖息的雌性更有可能在寄生的关键时期出现。平均而言，不栖息的个体可能会在牛鹂到达巢穴之后首先到达巢穴，这种差异在六个物种中非常显着。我们建议栖息在巢上可能会使宿主处于防止寄生的最佳位置，尽管这种行为并不总是能防止寄生。
We recorded vigilance around sunrise at 140 nests of 10 potential host-species (six "accepters" and four "rejecters" of cowbird eggs) of the brood parasitic Brown-headed Cowbird (Molothrus ater) at Delta Marsh, Manitoba, to determine if hosts are present on or near their nests when cowbirds come to lay. We predicted that accepter species parasitized infrequently would be found to be more vigilant at their nests during this time than accepter species more heavily parasitized. During our watches we observed seven acts of parasitism, all between 03:44 CST (sunrise 44 min) and 4:00 CST (sunrise 25 min). We found no correlation between frequency of parasitism of accepter hosts and nest attentiveness. There was no significant difference between accepters and rejecters in early-morning vigilance. However, females of all species that roosted on their nests were more likely to be present during the critical period for parasitism than females that did not roost. Individuals that did not roost first arrived at their nests, on average, after cowbirds presumably would have arrived to lay and this difference was significant in six species. We suggest roosting on the nest may place the host in the best position to guard against parasitism, although this behavior does not always prevent parasitism.