PDF(Pubmed)
Abstract：
Conspecific and interspecific brood parasitism are alternate reproductive strategies more pervasive in waterfowl than in any other group of birds. While previous research has measured costs incurred by nest hosts incubating parasitized clutches, few studies have focused on the relative success of parasites. Here, we evaluated the success of wood duck (Aix sponsa) and hooded merganser (Lophodytes cucullatus) eggs laid parasitically in Louisiana and Mississippi. We monitored nest boxes, assigned eggs in each nest as host or parasitic, and determined the number of eggs that hatched and failed. Across all study areas (1994-1999 and 2020-2023), we monitored 1750 wood duck and 377 hooded merganser nests; ~13% of wood duck and ~24% of hooded merganser nests were interspecifically parasitized. We modeled egg survival of 2925 host and 691 parasitic eggs from 197 successful nests (≥1 hatched egg, regardless of species). Wood duck eggs laid in hooded merganser nests had lower survival [0.293, CI = 95% credible intervals (after, CI) = 0.176, 0.439] than hooded merganser eggs (0.762, CI = 0.704, 0.810) laid in wood duck nests. Clutch size negatively influenced parasitic wood duck egg survival (β = -.24, CI = -0.39, -0.10) but had a slight positive influence on parasitic hooded merganser eggs (β = .08, CI = 0.04, 0.12). Our results revealed that hooded merganser eggs experience higher success when laid parasitically in wood duck nests, whereas wood duck eggs experience lower success when laid parasitically in hooded merganser nests. Our results reveal new complexity in waterfowl interspecific brood parasitism, where the success of parasitic eggs is species-, host-, and context-specific.
摘要：
与其他任何鸟类相比，在水禽中，种间和种间寄生是更普遍的替代繁殖策略。虽然先前的研究已经测量了巢穴宿主孵化寄生离合器所产生的成本，很少有研究关注寄生虫的相对成功。这里,我们评估了在路易斯安那州和密西西比州寄生产下的木鸭（Aixsposa）和连帽秋沙（Lophodytescucullatus）卵的成功。我们监控了巢箱，在每个巢中分配卵作为寄主或寄生虫，并确定了孵化和失败的卵的数量。在所有研究领域(1994-1999年和2020-2023年)，我们监测了1750个木鸭和377个带兜帽的秋沙鸭巢；约13％的木鸭和约24％的带兜帽的秋沙鸭巢被特异地寄生。我们对来自197个成功巢的2925个宿主和691个寄生卵的卵存活进行了建模（≥1个孵化卵，无论物种如何）。在带帽的秋沙鸭巢中产下的木鸭蛋的存活率较低[0.293，CI=95％可信间隔（之后，CI）=0.176，0.439]比在木鸭巢中产下的连帽秋葵卵（0.762，CI=0.704，0.810）。离合器的大小对寄生木鸭蛋的存活率产生了负面影响（β=-.24，CI=-0.39，-0.10），但对寄生带帽的小毛沙蛋有轻微的积极影响（β=.08，CI=0.04，0.12）。我们的结果表明，当寄生在木鸭巢中时，带帽的秋沙鸭卵获得了更高的成功，而木鸭蛋寄生在带兜帽的秋沙鸭巢中的成功率较低。我们的结果揭示了水禽种间寄生的新复杂性，寄生虫卵的成功是物种，主机-,和特定于上下文的。
