Ayala Andrea J, Cheng Matthew, Hellinger Thomas A, McBride K Mark, Webb Jonathan, Fanning Andrew, Snyder Paul, Ferragamo Margherita, Garcia Samantha C, Sterner Nyah, Bischoff Karyn L, Almagro-Moreno Salvador, Ogbunugafor C Brandon
Department of Natural Resources and the Environment, University of New Hampshire, Durham, New Hampshire, United States of America.
Department of Ecology and Evolutionary Biology, Yale University, New Haven, Connecticut, United States of America.
PLoS One. 2025 Mar 17;20(3):e0312653. doi: 10.1371/journal.pone.0312653. eCollection 2025.
The Florida Mottled Duck (Anas fulvigula fulvigula) is a unique subspecies of waterfowl whose range is limited to peninsular Florida, USA. As an endemic subspecies, Florida Mottled Ducks face numerous conservation stressors, such as habitat conversion and hybridization with non-native Mallards (Anas platyrhynchos). In addition to these numerous stressors, Mottled Ducks are also contending with emerging and/or geographically expanding waterborne pathogens such as Vibrio spp., due to the effects of climate change. However, even given their conservation needs, little is known with respect to the health, physiology, and the immunity of wild Mottled Ducks in Florida. Given this lack of data, we performed health assessments of Mottled Ducks in the Central Florida area. Specifically, we examined the humoral innate immune system, i.e., the plasma of Mottled Ducks in response to a common but extraneous pathogen: Escherichia coli strain American Type Culture Collection (ATCC) number 8739. We utilized a bactericidal assay ("bacterial killing assay" or BKA) commonly used in eco-immunology, to provide insight into the bactericidal capacities of captured Florida Mottled Ducks. We statistically tested the BKA capacity, or microbial killing ability, of 23 Mottled Ducks in response to age and whole blood lead levels (Pb). We found that there was no statistically significant relationship between the covariates we measured and Mottled Duck BKA capacity against E. coli. However, the variability we observed in the BKA capacity of this subspecies warrants further research into additional physiological and ecological covariates coupled with potential immune stressors that Florida Mottled Ducks may be contending with.
佛罗里达花脸鸭（Anas fulvigula fulvigula）是一种独特的水鸟亚种，其分布范围仅限于美国佛罗里达半岛。作为一个地方性亚种，佛罗里达花脸鸭面临着众多保护压力源，如栖息地转变以及与非本地绿头鸭（Anas platyrhynchos）杂交。除了这些众多压力源外，由于气候变化的影响，花脸鸭还在应对新出现的和/或地理范围不断扩大的水生病原体，如弧菌属。然而，即便考虑到它们的保护需求，对于佛罗里达野生花脸鸭的健康、生理和免疫情况，人们所知甚少。鉴于缺乏相关数据，我们对佛罗里达中部地区的花脸鸭进行了健康评估。具体而言，我们检测了体液固有免疫系统，即花脸鸭血浆对一种常见但外来的病原体：美国典型培养物保藏中心（ATCC）编号8739的大肠杆菌菌株的反应。我们采用了生态免疫学中常用的杀菌试验（“细菌杀伤试验”或BKA），以深入了解捕获的佛罗里达花脸鸭的杀菌能力。我们对23只花脸鸭针对年龄和全血铅水平（Pb）的BKA能力或微生物杀伤能力进行了统计测试。我们发现，我们测量的协变量与花脸鸭对大肠杆菌的BKA能力之间没有统计学上的显著关系。然而，我们在该亚种BKA能力中观察到的变异性，有必要进一步研究其他生理和生态协变量，以及佛罗里达花脸鸭可能面临的潜在免疫压力源。
