Hyperspectral images of King, Magnificent, and hybrid King of Holland's Bird-of-Paradise (Cicinnurus regius, C. magnificus, and C. magnificus x C. regius)

Hyperspectral imaging—a technique that combines the high spectral resolution of spectrophotometry with the high spatial resolution of photography—holds great promise for the study of animal coloration. However, applications of hyperspectral imaging to questions about the ecology and evolution of animal color remain relatively rare. The approach can be expensive and unwieldy, and we lack user-friendly pipelines for capturing and analyzing hyperspectral data in the context of animal color. Fortunately, costs are decreasing and hyperspectral imagers are improving, particularly in their sensitivity to wavelengths (including ultraviolet) visible to diverse animal species. To highlight the potential of hyperspectral imaging for animal color studies, we developed a pipeline for capturing, sampling, and analyzing hyperspectral data (here, in the 325nm - 700nm range) using avian museum specimens. Specifically, we used the pipeline to characterize the plumage colors of the King Bird-of-Paradise (Cicinnurus regius), Magnificent Bird-of-Paradise (C. magnificus), and their putative hybrid, the King of Holland’s Bird-of-Paradise (C. magnificus x C. regius). We also combined hyperspectral data with 3D digital models to supplement hyperspectral images of each specimen with 3D shape information. Using visual system-independent methods, we found that many plumage patches on the hybrid King of Holland’s Bird-of-Paradise are—to varying degrees—intermediate relative to those of the parent species. This was true of both pigmentary and structurally colored plumage patches. Using visual system-dependent methods, we showed that only some of the differences in plumage patches among the hybrid and its parent species would be perceivable by birds. Hyperspectral imaging is poised to become the gold standard for many animal coloration applications: comprehensive reflectance data—across the entire surface of an animal specimen—can be obtained in a matter of minutes. Our pipeline provides a practical and flexible roadmap for incorporating hyperspectral imaging into future studies of animal color.

Methods
This dataset was collected using a Resonon Pika NUV hyperspectral camera. Each image (BIL format, with .hdr files) was spatially calibrated to a PTFE standard, and each image contains a 99% reflectance standard for spectral calibration.

Images were collected for 6 male specimens (see paper for details), and included dorsal, ventral, and two lateral images (left, right), as well as a ventral image with the specimen tilted beak-toward the imager, and images of the dorsal side of the tail wires of the specimens.

We include some manually generated meta-data, including the location and size of the 99% reflectance standard in each image, and manually generated ROIs for various patches of each bird. In addition, we include angular data metadata in the form of renders of a 3D model for each hyperspectral image.

The Gouldian Finch sub-folder contains a hyperspectral image of a Gouldian Finch also collected with a Resonon Pika NUV hyperspectral camera (BIL format, with .hdr file), and was spatially calibrated to a PTFE and spectrally calibrated to a 99% reflectance standard (not present in the image).

高光谱成像（hyperspectral imaging）是一种将分光光度法的高光谱分辨率与摄影术的高空间分辨率相结合的技术，在动物体色研究中展现出巨大应用前景。然而，将高光谱成像应用于动物体色生态学与演化相关问题的研究仍相对较少。该方法往往成本高昂且操作繁琐，同时针对动物体色场景下的高光谱数据采集与分析，尚缺乏用户友好的工作流。值得庆幸的是，相关成本正不断降低，高光谱成像仪的性能也在持续提升，尤其是对多种动物可见的波长（包括紫外波段）的灵敏度得到改善。为凸显高光谱成像在动物体色研究中的应用潜力，我们开发了一套针对鸟类馆藏标本的高光谱数据采集、采样与分析流程（本次实验覆盖325nm至700nm波段）。

具体而言，我们利用该流程对红羽极乐鸟（Cicinnurus regius）、华美极乐鸟（C. magnificus）及其推定杂交种霍兰极乐鸟（C. magnificus × C. regius）的羽色特征进行了表征。此外，我们将高光谱数据与三维数字模型相结合，为每个标本的高光谱图像补充三维形态信息。通过不依赖视觉系统的分析方法，我们发现霍兰极乐鸟杂交种的诸多羽色斑块在不同程度上介于其亲本物种之间，这一结果同样适用于色素着色型与结构着色型羽色斑块。通过依赖视觉系统的分析方法，我们证实仅部分杂交种与亲本物种间的羽色差异可被鸟类感知。高光谱成像有望成为众多动物体色研究应用的金标准：仅需数分钟即可获取动物标本全表面的全面反射率数据。我们开发的流程为将高光谱成像技术纳入未来动物体色研究提供了一套实用且灵活的技术路线图。

方法
本数据集采用Resonon Pika NUV高光谱相机采集。所有图像均采用BIL格式，附带.hdr文件，已通过聚四氟乙烯（Polytetrafluoroethylene, PTFE）标准进行空间校准，每张图像均包含用于光谱校准的99%反射率标准板。

共采集6份雄性标本的图像（详细信息参见论文），包括背侧、腹侧及两侧（左侧、右侧）视图，另有一份标本喙部朝向成像设备的腹侧视图，以及标本尾羽金属丝结构的背侧视图。

我们附带了部分手动生成的元数据，包括每张图像中99%反射率标准板的位置与尺寸，以及针对各鸟类不同羽区手动绘制的感兴趣区域（Regions of Interest, ROIs）。此外，我们还附带了以三维模型渲染形式存在的角度数据元数据，对应每张高光谱图像。

七彩文鸟（Gouldian Finch）子文件夹包含一份同样采用Resonon Pika NUV高光谱相机采集的七彩文鸟高光谱图像（BIL格式，附带.hdr文件），该图像已通过聚四氟乙烯标准完成空间校准，并通过99%反射率标准完成光谱校准（标准板未出现在图像中）。