PARENTAL INVESTMENT IN NEST DEFENSE BY STONECHATS (SAXICOLA-TORQUATA)
PARENTAL INVESTMENT IN NEST DEFENSE BY STONECHATS (SAXICOLA-TORQUATA)
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DOI：
10.1016/s0003-3472(80)80069-8
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发表时间：
1980-01-01
期刊：
影响因子：
2.5
通讯作者：
GREIGSMITH, PW
中科院分区：
文献类型：
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作者：
GREIGSMITH, PW
繁殖中的石头鸟（S. torquata）在人类入侵者进入领地时，会发出混合的两种叫声。whitits是一种频率范围很小的调制音符，在实验室测试中可以使雏鸟停止乞讨。“呜呜”声覆盖了很宽的频率范围，并且在野外与飞行相结合，以分散入侵者的注意力。平均而言，雄性和雌性的叫声率相似，但根据入侵者与巢穴的距离和筑巢周期的不同阶段而有很大差异。孵化后率迅速上升；这与父母喂养雏鸟的累计次数密切相关。防御水平可以根据后代对父母的价值来调整。电话通过率在羽翼未熟后约1周下降。在孵化开始时，一些配对的峰值较小，显然与之前的繁殖尝试和产下大量卵后的条件不佳有关。在渐近线上，雏鸟数量较多的巢中白斑的发生率较高，但雏鸟的发生率与雏鸟数量无关。遭受巢捕食的鸟类在事件发生前的鸣叫率低于同等成功的鸟类，这表明鸣叫降低了被捕食的风险。
Breeding stonechats (S. torquata) made mixed sequences of 2 calls when a human intruder entered territories. Whits are modulated notes with a small frequency range, and in laboratory tests caused nestlings to stop begging. Chacks cover a wide range of frequencies, and in the field were combined with flights made so as to distract an intruder from the nest. On average male and female call-rates were similar, but varied greatly according to the intruder''s distance from the nest and at different stages of the nesting cycle. Rates increased rapidly after hatching; this correlated most closely with the cumulative total of parents'' visits to feed nestlings. The level of defense may be adjusted to the value of the offspring to their parents. Call-rates declined about 1 wk after fledging. A smaller peak by some pairs at the start of incubation was apparently related to probable poor condition after a previous breeding attempt, and after laying large clutches. Rates of whits were higher at nests with larger broods, up to an asymptote, but rates of chacks were independent of brood size. Birds suffering nest-predation showed lower call-rates before the event than equivalent successful birds, suggesting that the calls reduce the risk of predation.