Cunningham Susan J, Alley Maurice R, Castro Isabel
Ecology Group, Institute of Natural Resources, Massey University, Palmerston North, New Zealand.
J Morphol. 2011 Jan;272(1):118-28. doi: 10.1002/jmor.10908. Epub 2010 Nov 10.
Knowledge of structure in biology may help inform hypotheses about function. Little is known about the histological structure or the function of avian facial bristle feathers. Here we provide information on morphology and histology, with inferences for function, of bristles in five predominantly insectivorous birds from New Zealand. We chose species with differing ecologies, including: brown kiwi (Apteryx mantelli), morepork (Ninox novaezealandae), hihi (Notiomystis cincta), New Zealand robin (Petroica australis), and New Zealand fantail (Rhipidura fuliginosa). Average bristle length corrected for body size was similar across species. Bristles occurred in distinct groups on different parts of the head and upper rictal bristles were generally longest. The lower rictal bristles of the fantail were the longest possessed by that species and were long compared to bristles of other species. Kiwi were the only species with forehead bristles, similar in length to the upper rictal bristles of other species, and the lower rictal bristles of fantails. Herbst corpuscles (vibration and pressure sensitive mechanoreceptors) were found in association with bristle follicles in all species. Nocturnal and hole-nesting birds had more heavily encapsulated corpuscles than diurnal open-nesting species. Our results suggest that avian facial bristles generally have a tactile function in both nocturnal and diurnal species, perhaps playing a role in prey handling, gathering information during flight, navigating in nest cavities and on the ground at night and possibly in prey-detection. These differing roles may help explain the observed differences in capsule thickness of the corpuscles.
生物学中的结构知识可能有助于形成关于功能的假设。人们对鸟类面部刚毛羽毛的组织结构或功能知之甚少。在此，我们提供了关于新西兰五种主要食虫鸟类刚毛的形态学和组织学信息，并对其功能进行了推断。我们选择了具有不同生态习性的物种，包括：褐几维鸟（Apteryx mantelli）、新西兰蟆口鸱（Ninox novaezealandae）、吸蜜鸟（Notiomystis cincta）、新西兰知更鸟（Petroica australis）和新西兰扇尾鹟（Rhipidura fuliginosa）。校正体型后的平均刚毛长度在各物种间相似。刚毛分布在头部不同部位的不同组中，上嘴角刚毛通常最长。扇尾鹟的下嘴角刚毛是该物种中最长的，与其他物种的刚毛相比也较长。几维鸟是唯一在前额有刚毛的物种，其长度与其他物种的上嘴角刚毛以及扇尾鹟的下嘴角刚毛相似。在所有物种中，均发现赫伯斯特小体（对振动和压力敏感的机械感受器）与刚毛囊相关联。夜行性和洞穴筑巢的鸟类比日行性露天筑巢的物种有更多被包裹得更紧密的小体。我们的研究结果表明，鸟类面部刚毛在夜行性和日行性物种中通常都具有触觉功能，可能在处理猎物、飞行中收集信息、在巢穴和夜间地面导航以及可能在猎物探测中发挥作用。这些不同的作用可能有助于解释观察到的小体被膜厚度的差异。
