Proximate and Ultimate Roles of Food Amount in Regulating Egret Sibling Aggression.
Proximate and Ultimate Roles of Food Amount in Regulating Egret Sibling Aggression.
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食物量在调节白鹭同胞攻击行为中的直接和最终作用。
DOI：
10.2307/1939867
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发表时间：
1987
期刊：
影响因子：
4.8
通讯作者：
Bonnie J. Ploger
中科院分区：
文献类型：
--
作者：
D. Mock;T. C. Lamey;Bonnie J. Ploger
在专杀幼鸟的物种中，亲鸟传递给幼鸟的食物量（“食物量”）被认为是致命攻击的重要近因和最终原因。近似的“食物量假说”（FAH）认为，兄弟姐妹的攻击将与父母提供的食物量成反比，可能是由小鸡饥饿介导的。在最终的水平上，食物短缺预计会影响到侵略和食物控制的综合影响是否会致命的最年轻的育雏成员（S）。研究结果表明：（1）白鹭（Casmerodius albus）和苍鹭（Ardea herodias）的同胞攻击性并没有像预测的那样随着食物量的增加而下降，甚至可能是弱正相关。(2)在白鹭的育雏，最强的预测总育雏成功率的竞争活力的最年轻的同胞和战斗率。(3)野生白鹭育雏的食物量增加一倍，实验并没有减少战斗率，但经历了显着降低育雏减少比对照育雏。(4)人工饲养的白鹭雏鸟，其食物量的实验减少并没有增加战斗率，但遭受显着更多的育雏减少比控制育雏。(5)在野外，食物量似乎不是一个足够稳定的参数，谨慎的兄弟姐妹侵略战略的基础上。我们的结论是，食物的数量有很少的直接影响战斗行为在这些鸟类，但它始终影响小鸡的生存。因此，这个生态变量的近因效应必须与它的最终作用相分离，至少在像这些鹭科植物和专性亲兄弟种这样的物种中是这样。然而，FAH可能很好地解释了其他亲兄弟鸟类中的兄弟争斗变异，如蓝脚鲣鸟（苏拉nebouxii），黑腿三趾鸥（里萨tridactyla），鱼鹰（Pandion haliaetus）和南极贼鸥（Catharacta maccormicki）。在食物波动相对缓慢的物种中，同胞攻击行为可能具有食物量依赖性。试图操纵猎物独占性（丸大小）在圈养大白鹭是不成功的，无论是因为在实验室中的同胞的侵略是如此膨胀，沼泽猎物大小的影响，或者因为这个物种根本缺乏足够的发展灵活性，在其巢内战斗行为。如果后者是真的，这将揭示大白鹭和大蓝鹭之间的显著差异，它们在这方面表现出相当大的（适应性）可塑性。
In facultatively siblicidal bird species, the amount of food delivered by parent birds to their young ("food amount") has been assumed to be both an important proximate and ultimate cause of fatal aggression. The proximate "Food Amount Hypothesis" (FAH) contends that sibling aggression will vary inversely with the quantity of food delivered by the parents, presumably mediated by chick hunger. At the ultimate level, food shortages are expected to influence whether the combined effects of aggression and food control by older siblings will be fatal to the youngest brood member(s). We evaluated the effects of food amount on aggression and survival in facultatively siblicidal Ardeidae: (1) Sibling aggression in unmanipulated broods of Great Egrets (Casmerodius albus) and Great Blue Herons (Ardea herodias) did not decline with increasing amounts of food, as had been predicted; indeed, this relationship may even be weakly positive. (2) In egret broods, the strongest predictors of total brood success were competitive vigor of the youngest sib and fighting rate. (3) Wild egret broods whose food amount was experimentally doubled did not reduce fighting rates, but experienced significantly lower brood reduction than control broods. (4) Captive egret broods whose food amount was experimentally decreased did not increase fighting rates, but suffered significantly more brood reduction than control broods. (5) In the wild, food amount appears not to be a sufficiently stable parameter on which to base prudent sib-aggression strategies. We conclude that food amount has little direct influence on fighting behavior in these birds, though it consistently influences chick survival. Thus the proximate effects of this ecological variable must be divorced from its ultimate role, at least in species such as these ardeids and in obligate-siblicidal species. However, the FAH may well account for sib-fighting variation in other facultatively siblicidal birds, such as Blue-footed Boobies (Sula nebouxii), Black-legged Kittiwakes (Rissa tridactyla), Ospreys (Pandion haliaetus), and South Polar Skuas (Catharacta maccormicki). It is predicted that sibling aggression will be food-amount dependent in species whose food fluctuations are relatively slow. An attempt to manipulate prey monopolizability (bolus size) in captive Great Egrets was unsuccessful, either because sib aggression in the laboratory was so inflated as to swamp prey-size effects or because this species simply lacks sufficient developmental flexibility in its intrabrood fighting behavior. If the latter were true, it would reveal a striking difference between Great Egrets and Great Blue Herons, which have shown considerable (adaptive) plasticity in this regard.