<b>Host personality and seasonal parasitism risk do not account for egg rejection behavior in the azure-winged magpie</b>

Recent studies have shown that host egg rejection behavior varies according to personality traits and parasitism risk. However, these relationships have not been clearly determined.The study was conducted in April–June 2024. The study site was located in Fusong County, Baishan City, Jilin Province, northeastern China (42°42ʹ N, 127°01′ E). The region is located in the temperate zone with an average elevation of 481 meters, a continental monsoon climate with cold and snowy winters, and an average annual temperature of 4°C (Yang et al., 2019).The azure-winged magpie belongs to the order Passeriformes and family Corvidae. It is widely distributed in the eastern Palearctic region and exhibits cooperative breeding behavior. Azure-winged magpies are typical resident birds in most parts of China (Zheng 2023); however, azure-winged magpies at the study site appeared in surrounding coniferous forests near populated areas only around April. These birds mainly used sporadically distributed artificially planted spruce (<i>Picea asperata</i>) and red pine (<i>Pinus koraiensis</i>) woods for nesting (Liu et al. 2023). In Europe, the azure-winged magpie is a host of the great spotted cuckoo (<i>Clamator glandarius</i>) (Avilés et al., 2004). In Japan, it serves as an important host for the common cuckoo (Nakamura, 1990). In China, it is parasitized by common cuckoos, Indian cuckoos (<i>Cuculus micropterus</i>) (Nakamura et al., 1998), and Asian koels (<i>Eudynamys scolopaceus</i>) (Lin et al., 2024).The aim of this study was to further investigate the influence of seasonal parasitism pressure and host personality traits on egg rejection behavior in the azure-winged magpie<i> </i>(<i>Cyanopica cyanus</i>). Our results showed no significant difference in the proportion of egg rejection between hosts with low (before the arrival of cuckoos) and high (after the arrival of cuckoos) parasitism pressure. In addition, no significant difference was detected in the proportion of egg rejection between bold individuals (shorter flight initiation distance, FID) and shy individuals (longer FID). We hypothesized that the relatively weak effect of the presence or absence of cuckoos on this species could be attributed to their inherently strong egg recognition abilities. Moreover, the quantification of host behavior along a single personality axis (boldness–shyness) may be insufficient to capture behavioral differences that arise from the combined effects of various personality traits. Our study provides novel insights into the influence of seasonal parasitism risk and personality traits on host egg recognition behavior.

已有研究表明，宿主的拒卵行为会随其个性特征与寄生风险发生变化，但二者间的具体关联尚未明确。
本研究于2024年4月至6月开展，研究地点位于中国东北吉林省白山市抚松县（北纬42°42′，东经127°01′）。该区域地处温带，平均海拔481米，属大陆性季风气候，冬季寒冷多雪，年平均气温为4℃（Yang等，2019）。
灰喜鹊（azure-winged magpie）隶属于雀形目（Passeriformes）鸦科（Corvidae），广泛分布于古北界东部区域，具有合作繁殖行为。灰喜鹊是中国大部分地区的典型留鸟（Zheng，2023），但本研究区域内的灰喜鹊仅在每年4月左右现身于居民区周边的针叶林地带。该鸟类主要营巢于零星分布的人工云杉（<i>Picea asperata</i>）与红松（<i>Pinus koraiensis</i>）林（Liu等，2023）。
在欧洲，灰喜鹊是大斑凤头鹃（<i>Clamator glandarius</i>）的宿主（Avilés等，2004）；在日本，其为大杜鹃（common cuckoo）的重要宿主（Nakamura，1990）；在中国，灰喜鹊会被大杜鹃、四声杜鹃（<i>Cuculus micropterus</i>）（Nakamura等，1998）以及噪鹃（<i>Eudynamys scolopaceus</i>）（Lin等，2024）寄生。
本研究旨在进一步探究季节寄生压力与宿主个性特征对灰喜鹊（<i>Cyanopica cyanus</i>）拒卵行为的影响。
研究结果显示，寄生压力较低（大杜鹃抵达前）与较高（大杜鹃抵达后）的宿主，其拒卵比例无显著差异。此外，大胆个体（惊飞距离（flight initiation distance, FID）更短）与害羞个体（FID更长）的拒卵比例亦无显著差异。
我们推测，大杜鹃存在与否对该物种的影响相对较弱，可能源于其本身具备较强的卵识别能力。此外，仅通过单一个性轴（大胆-害羞）量化宿主行为，可能不足以捕捉由多种个性特征共同作用所产生的行为差异。
本研究为季节寄生风险与个性特征对宿主卵识别行为的影响提供了新的研究视角。