PDF(Pubmed)
Abstract：
In the southeastern United States, wood ducks (Aix sponsa) have historically experienced interspecific brood parasitism (IBP) primarily from hooded mergansers (Lophodytes cucullatus), but the recent northward expansion of black-bellied whistling-ducks (Dendrocygna autumnalis) has added a new complexity to these interactions. We monitored nest boxes in Louisiana to evaluate the influence IBP had on wood duck daily nest survival rate (after, DSR) and duckling recruitment. We monitored 1,295 wood duck nests from 2020-2023 and found 112 (8.7%) were parasitized by hooded mergansers and 148 (11.5%) by whistling-ducks. Parasitic egg-laying by hooded mergansers lowered wood duck DSR, while DSR for nests parasitized by whistling-ducks was comparable to clutches containing only wood duck eggs. We considered the wood duck capture histories of 2,465 marked female ducklings and 540 banded adult females to estimate a duckling recruitment probability for the entire study period. We recaptured 50 ducklings as adults; 6 (12.0%) hatched from clutches parasitized by hooded mergansers, 1 (2.0%) from a clutch parasitized by a whistling-duck, and 43 (86.0%) from clutches containing only wood duck eggs. The duckling recruitment probability was 0.039 (95% credible interval = 0.028, 0.051). Nest initiation date had a negative effect on recruitment, wherein most recruits hatched from nests initiated earlier in the season. Given only ~9% of wood duck nests contained hooded merganser eggs, we conclude IBP writ large had no detrimental effect on DSR at a population level. The lower DSR of clutches parasitized by hooded mergansers is potentially linked to a high abundance of early-season parasites that produce \"dump nests\" and these clutches are often abandoned without being incubated. Despite ongoing parasitism by hooded mergansers and the range expansion of whistling-ducks, wood duck productivity in Louisiana appears to be minimally affected by interspecific brood parasitism.
摘要：
在美国东南部,木鸭（Aixsponsa）历史上曾经历过种间寄生（IBP），主要来自带帽的白头翁（Lophodytescucullatus），但是最近黑腹口哨鸭（Dendrocycgnaautumnalis）向北扩展为这些相互作用增加了新的复杂性。我们监测了路易斯安那州的巢箱，以评估IBP对木鸭日巢存活率的影响(后，DSR）和小鸭招募。从2020年至2023年，我们监测了1,295个木鸭巢，发现有112个（8.7％）被带帽的秋葵寄生，有148个（11.5％）被吹口哨的鸭子寄生。带帽的秋葵降低了木鸭DSR，而由鸣笛鸭寄生的巢的DSR可与仅包含木鸭蛋的离合器相媲美。我们考虑了2,465只标记的雌性小鸭和540只带状成年雌性的木鸭捕获历史，以估计整个研究期间的小鸭招募概率。我们成年后重新捕获了50只小鸭；6只（12.0％）从被带帽的秋葵寄生的离合器中孵化出来，1（2.0％）来自被吹口哨的鸭子寄生的离合器，和43（86.0％）来自仅包含木鸭蛋的离合器。小鸭招募概率为0.039(95%可信区间=0.028、0.051)。巢开始日期对招募有负面影响，其中大多数新兵是从赛季初开始的巢穴中孵化出来的。考虑到只有约9％的木鸭巢含有带帽的秋沙鸭卵，我们得出的结论是，在人口水平上，大型IBP对DSR没有不利影响。被带帽的秋沙菌寄生的离合器的DSR较低，可能与大量产生“倾卸巢”的早期寄生虫有关，这些离合器通常在没有孵化的情况下被遗弃。尽管连帽的秋沙菌持续寄生，口哨鸭的范围扩大，路易斯安那州的木鸭生产力似乎受到种间繁殖寄生的影响最小。
