<b>Have Asian Koels Evolved Egg Mimicry with Any of Their Hosts?</b>

To determine if the koel has evolved mimicry of the eggs of any of its hosts, we took objective measurements of koel and host egg color, luminance, pattern and size using reflectance spectrophotometry, photographs and calipers. We only measured one host and one koel egg per clutch to reduce the chances of pseudoreplication. For most species, when multiple hosts or koel eggs were in a nest, we used a random number generator to decide which egg to measure. However, for some host species that had high levels of intraclutch variation, we chose one host egg that looked representative of the entire clutch. The color, luminance, pattern and size of some eggs were measured in 2015 and 2019 from the Natural History Museum (NHM) in Tring, UK (please see below sections for more detail on methods and equipment). All the NHM eggs were collected between 1867 and 1943 from Bangladesh, India, Pakistan, Sri Lanka, Myanmar, Thailand, Indonesia and China. The sizes of other eggs were measured from 2008-2017 at a field site at Jahangirnagar University, Dhaka, Bangladesh using digital calipers. At this same site, we photographed additional eggs in the field from 2015-2017 to measure pattern. Most of these were fresh eggs that still contained contents, so these eggs were only used in the pattern and size analyses, as color and luminance may vary greatly between older museum eggs and fresh eggs (Cassey et al., 2010a, b, 2012). We measured both parasitized and unparasitized clutches for 11 different host species of three koel subspecies (<i>E. s. chinensis</i>, <i>E. s. malayana</i>, and <i>E. s. scolopaceus</i>) from multiple countries (Table 1; Table 2; Figure 1; Supplementary Material, Table S1). Unparasitized clutches were measured to increase our sample size of host eggs, so host eggs from unparasitized and parasitized clutches were combined in all analyses. We found no evidence that koels have evolved host-specific egg types. In general, koels did not show strong egg mimicry when compared to the eggs of the host species they parasitized in the collection, including the House Crow. However, koel eggs were the most similar in pattern to the Red-billed Blue Magpie (<i>Urocissa erythrorhyncha</i>) and the Eastern Jungle and Large-billed Crows (<i>Corvus</i><i> leveillanti</i> and <i>C.</i> <i>macrorhynchus</i>), and were the most similar in color to the Red-billed Blue Magpie. This suggests that koels may have evolved eggs that mimic the eggs of these hosts, rather than the eggs of the House Crow.

为确定噪鹃是否演化出针对其宿主卵的拟态，我们采用反射光谱法、摄影技术与游标卡尺，对噪鹃卵与宿主卵的颜色、亮度、斑纹及大小进行了客观测量。为降低伪重复风险，我们每窝仅测量一枚宿主卵与一枚噪鹃卵。针对多数物种，当巢内存在多枚宿主卵或噪鹃卵时，我们通过随机数发生器选定待测卵；但对于部分窝内变异程度较高的宿主物种，我们选取一枚具有窝卵整体代表性的宿主卵进行测量。部分卵的颜色、亮度、斑纹与大小数据采集于2015年与2019年，源自英国特灵自然历史博物馆（Natural History Museum, NHM）（详细方法与设备信息参见下文章节）。所有NHM馆藏卵均采集于1867年至1943年间，采集地包括孟加拉国、印度、巴基斯坦、斯里兰卡、缅甸、泰国、印度尼西亚与中国。其余卵的大小则于2008年至2017年间，在孟加拉国达卡的贾汉吉尔纳加尔大学野外站点通过数字游标卡尺完成测量。2015年至2017年间，我们在同一站点对野外额外卵样进行摄影以分析其斑纹；其中多数为仍内含内容物的新鲜卵，因此仅用于斑纹与大小分析——因为馆藏陈年卵与新鲜卵的颜色与亮度可能存在显著差异（Cassey等，2010a、b，2012）。我们针对3个噪鹃亚种（*E. s. chinensis*、*E. s. malayana*与*E. s. scolopaceus*）的11个不同宿主物种，从多个国家采集了被寄生与未被寄生的窝卵样本（表1、表2、图1、补充材料表S1）。未被寄生的窝卵被用于扩充宿主卵样本量，因此所有分析均合并了来自被寄生与未被寄生窝卵的宿主卵数据。研究未发现噪鹃演化出宿主特异性卵型的证据。总体而言，相较于其寄生宿主的卵（包括家鸦），噪鹃卵未表现出显著的拟态特征。但噪鹃卵的斑纹与红嘴蓝鹊（*Urocissa erythrorhyncha*）、东方丛林鸦与大嘴乌鸦（*Corvus leveillanti*与*C. macrorhynchus*）最为相似，其颜色则与红嘴蓝鹊最为接近。这表明噪鹃可能演化出了针对上述宿主的卵拟态，而非针对家鸦的拟态。