A wide range of animal species accumulate objects in, on, and/or around structures they build. Sometimes, these accumulations serve specific functions (e.g. structural or isolating features) or are purely incidental, while in other cases the materials are deliberately displayed to serve signalling purposes (extended phenotype signals). In this pilot study, we employed systematic in situ observations and camera trapping to describe for the first time that both partners of a territorial shorebird, the black-faced sheathbill (Chionis minor ssp minor) collect, carry, and arrange colourful marine shells and dry twigs within and around their nest cavity. Our observations expand the taxonomic breadth of avian extended phenotype signals, by showing that at least one species within a largely understudied group i.e., Charadriiformes, exhibits nest-decoration behaviour. Multiple manipulative experiments are needed to explore further the signalling function of these decorations, which opens new exciting avenues for animal communication and cognition research.

各种各样的动物物种会在它们建造的结构之中，之上和/或周围积累物体。有时，这些积累物发挥特定功能（例如，结构或隔离特征）或纯粹是偶然的，而在其他情况下，则故意展示材料以达到信号传递目的（扩展的表型信号）。在这项先导研究中，我们采用系统的原位观察和照相机诱捕技术首次描述了陆地水鸟的两个伴侣-黑面sheath（Chionis minor ssp minor））在其巢腔内和巢腔周围收集，携带和布置五颜六色的海贝壳和干树枝。我们的观察结果表明，在很大程度上未被充分研究的群体中，至少有一个物种，即Charadriiformes，表现出巢装饰行为，从而扩展了禽类扩展表型信号的分类学广度。需要进行多次操纵实验来进一步探索这些装饰物的信号传导功能，这为动物交流和认知研究开辟了新的令人兴奋的途径。