Polak Celeste, Ottenburghs Jente
Wildlife Ecology and Conservation Wageningen University Wageningen the Netherlands.
Forest Ecology and Forest Management Wageningen University Wageningen the Netherlands.
Ecol Evol. 2025 Apr 27;15(4):e71028. doi: 10.1002/ece3.71028. eCollection 2025 Apr.
The solar glare hypothesis suggests that the malar stripe of a falcon decreases the sun's glare in the eye, possibly increasing their hunting success. The amount of sunlight an individual experiences could be affected by its migratory strategy, hunting style or main habitat. However, it is not known if these environmental variables impact the size and intensity of the malar stripe. Therefore, this study aimed to analyse differences in size and intensity of malar stripes between individuals of 12 falcon species with different migratory strategies, habitats, and hunting styles distributed worldwide. The malar stripes of 12 falcon species were measured and scored using more than 6000 photos from citizen science repositories. The measurements of the malar stripes were first reduced with a principal component analysis (PCA) and then analysed using a linear mixed model that included migratory strategy, habitat and hunting style as fixed factors and several posture variables as random factors. The relationships between the measurements of the malar stripe and solar radiation of the individual's location were also analyzed using linear mixed models. Overall, we found no differences in malar stripe size and intensity between species with differing migratory strategies, habitats, and hunting styles. The relationships between various characteristics of the malar stripe and solar radiation did depend on the species and the habitat the individual occupied. Therefore, migratory strategy, habitat and hunting style do not markedly influence the size and intensity of malar stripes across falcon species, suggesting that other mechanisms, such as thermoregulation or camouflage, also play a role.
太阳眩光假说认为，猎鹰的颧纹可减少眼睛接收到的太阳眩光，这可能会提高它们的捕猎成功率。个体所经历的阳光量可能会受到其迁徙策略、捕猎方式或主要栖息地的影响。然而，尚不清楚这些环境变量是否会影响颧纹的大小和亮度。因此，本研究旨在分析全球分布的12种具有不同迁徙策略、栖息地和捕猎方式的猎鹰个体之间颧纹大小和亮度的差异。利用来自公民科学数据库的6000多张照片，对12种猎鹰的颧纹进行了测量和评分。颧纹的测量数据首先通过主成分分析（PCA）进行降维，然后使用线性混合模型进行分析，该模型将迁徙策略、栖息地和捕猎方式作为固定因素，将几个姿势变量作为随机因素。还使用线性混合模型分析了颧纹测量值与个体所在位置太阳辐射之间的关系。总体而言，我们发现具有不同迁徙策略、栖息地和捕猎方式的物种之间，颧纹大小和亮度没有差异。颧纹的各种特征与太阳辐射之间的关系确实取决于物种和个体所占据的栖息地。因此，迁徙策略、栖息地和捕猎方式并不会显著影响猎鹰物种间颧纹的大小和亮度，这表明其他机制，如体温调节或伪装，也发挥了作用。
