Helping does not enhance reproductive success of cooperatively breeding rufous vanga in Madagascar
Helping does not enhance reproductive success of cooperatively breeding rufous vanga in Madagascar
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DOI：
10.1046/j.0021-8790.2001.00585.x
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发表时间：
2002-01-01
影响因子：
4.8
通讯作者：
Hino, T
中科院分区：
文献类型：
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作者：
Eguchi, K;Yamagishi, S;Hino, T
1.在许多合作育种的研究中，辅助个体的帮助被认为可以提高育种者的繁殖成功率。然而，除了帮助之外的混杂因素也可能导致差异。为了评价辅助鸟对该物种繁殖的影响，我们对马达加斯加西部安皮霍罗阿森林站的一个单独的彩色带种群进行了为期6年的研究，比较了辅助鸟对繁殖和单独繁殖的繁殖成功率。该物种为单卵。巢减少是罕见的，大多数情况下，筑巢失败是由于完全失去离合器和育雏，可能是由于捕食。一夫一妻制与1至4只辅助鸟组成的配对占所有繁殖群体的24-43%。大多数辅助鸟的雄性后代留在其纳塔尔领土，辅助男性提供了相当大的贡献，对反捕食防御，领土防御和提供雏鸟。然而，在大约三分之一的群体中，辅助男性根本没有帮助。雄性后代可能会留在纳塔尔地，以避免其他领土个体的骚扰，并增加获得领土和与无关的繁殖雌性交配的可能性。繁殖成功的概率更高，与辅助鸟配对产生的雏鸟数量也比单独繁殖的雏鸟多。然而，辅助供应既没有提高雏鸟的生长速度，也没有减少他们所需的天数。配对配对比较相同的对之间的年和没有辅助显示组大小对他们的繁殖成功没有影响。即使辅助供给也不影响繁殖成功。配对伴随辅助鸟超过1年享有更高的繁殖成功率，即使在那些年里，当他们没有辅助比对总是单独繁殖。无论是简单的辅助，也不是他们的帮助行为增强繁殖成功的繁殖对。繁殖对的质量和/或它们的领地可能影响了它们的繁殖成功，因此增加了辅助动物的数量。
1. In many studies on cooperative breeding, helping by auxiliary individuals is considered to enhance the reproductive success of breeders. However, confounding factors other than helping could cause the differences.2. The endemic Madagascan rufous vanga Schetba rufa (Vangidae) is known as a cooperatively breeding species, In order to evaluate the effect of helping in this species, we compared the reproductive success of breeding pairs helped by auxiliary birds, and pairs breeding alone, based on a 6-year study of an individually colour-banded population in the Ampijoroa Forest Station, western Madagascar.3. This species is single-brooded. Brood reduction was rare and most cases of nesting failure were due to total loss of clutches and broods, probably as a result of predation.4. Monogamous pairs with one to four auxiliary birds comprised 24-43% of all breeding groups. Most auxiliary birds were male offspring remaining in their natal territory, Auxiliary males provided a considerable contribution towards antipredator defence, territory defence and to the provisioning of nestlings. In about one-third of the groups, however, the auxiliary males did not help at all. Male offspring may remain in their natal territory in order to avoid harassment by other territorial individuals, and to increase the probability of territory acquisition and of copulation with unrelated breeding females.5. The probability of breeding successfully was higher, and the number of fledglings produced was larger among pairs with auxiliary birds than among those breeding alone. However, provisioning by auxiliaries neither enhanced the growth rate of nestlings, nor reduced the number of days they required to fledge.6. A pair-match comparison of the same pairs between years with and without auxiliaries showed no effect of group size on their reproductive success. Even provisioning by auxiliaries did not affect the reproductive success.7. Pairs accompanied by auxiliary birds for more than 1 year enjoyed higher reproductive success even in those years when they were without auxiliaries than did pairs always breeding alone.8. Neither the simple presence of auxiliaries nor their helping behaviour enhanced the reproductive success of breeding pairs. The quality of the breeding pair and/or their territory may have affected their reproductive success and, as a result, increased the number of auxiliaries.