EXPERIMENTAL-EVIDENCE FOR HELPING AND HINDERING BY PREVIOUS OFFSPRING IN THE COOPERATIVE-BREEDING SEYCHELLES WARBLER ACROCEPHALUS-SECHELLENSIS
EXPERIMENTAL-EVIDENCE FOR HELPING AND HINDERING BY PREVIOUS OFFSPRING IN THE COOPERATIVE-BREEDING SEYCHELLES WARBLER ACROCEPHALUS-SECHELLENSIS
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DOI：
10.1007/s002650050031
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发表时间：
1994-03-01
影响因子：
2.3
通讯作者：
KOMDEUR, J
中科院分区：
文献类型：
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作者：
KOMDEUR, J
繁殖前塞舌尔莺（Acrocephalus secellensis）经常在其纳塔尔领土上充当帮手，帮助领土防御，捕食者围攻，筑巢，孵化（仅限女性）和喂养父母的依赖年轻人。在某些情况下，协助者可以在其纳塔尔群体中获得繁殖地位（例如通过联合筑巢），并成为共同繁殖者。在一个给定的质量领土上的群体规模和繁殖成功的比较表明，存在的异源父母（助手和cobreeders）显着影响其父母的繁殖成功。通过从育种单位中去除异源亲本，并比较自然大小和人工减少的群体的成功，研究了异源亲本对繁殖成功的影响。去除实验，控制领土质量，组的大小和育种年龄，表明，存在一个异源显着提高其父母的繁殖成功。分析强烈表明，这完全是由于帮助行为（即照顾父母的后代），从而提高了帮助者留在家里的包容性健身效益。然而，这些实验也表明，与只有一个异源亲本的群体相比，在中等质量的领土上存在两个或更多的异源亲本显着降低了繁殖成功率。一些证据表明，这可能是由于联合筑巢和繁殖竞争，可能会发生在繁殖群体，或只是资源抑郁症时，大量以前的后代留在他们的纳塔尔领土。
Prebreeding Seychelles warblers (Acrocephalus sechellensis) frequently act as helpers on their natal territory, aiding in territory defence, predator mobbing, nest-building, incubation (only females) and feeding dependent young of their parents. In some cases helpers could attain breeding status (e.g. by joint-nesting) in their natal group and become co-breeders. Comparisons of group size and reproductive success on a given quality territory suggest that the presence of alloparents (helpers and cobreeders) significantly affects the reproductive success of their parents. The influence of alloparents on reproductive success was examined by removing alloparents from breeding units and comparing the success of natural-sized and artificially reduced groups. Removal experiments, controlled for territory quality, group size and breeder age, showed that the presence of one alloparent significantly improved the reproductive success of its parents. Analysis strongly suggests that this was entirely due to helping behaviour (i.e. providing care to offspring of their parents), thereby improving the helper's inclusive fitness benefits from staying at home. However, these experiments showed also that the presence of two or more alloparents in medium-quality territories significantly decreased reproductive success, compared with groups with one alloparent. Several lines of evidence suggest that this may have been due to the joint-nesting and reproductive competition that could occur in breeding groups, or simply to resource depression when a large number of previous offspring remained on their natal territory.