Appearance and Digestive System Comparison of Lonchura Striata and Copsychus Saularis: Searching for the Effect of Staple Feeding Ingredients on Avian Morphology

ABSTRACT This study explores the differences of appearance and the digestive systems of two birds (Lonchura striata and Copsychus saularis), which have the same eating pattern in staple ingredients. Each bird was caught naturally and euthanized in appropriate manner, followed by morphology survey on bill, duodenum, jejunum, ileum and appearance of the body parts such as Culmen, Claw, Wing, Tarsus, Toe and Tail. The results showed that the appearance feature between them presented significant differences in the beak length, wing length and tail length, which were correlated to their staple feeding habits. In addition, in the digestive system, the length of duodenum and duodenal indexes showed significant differences (p<0.05 or p<0.01), which was considered to be correlated to their predation rate. However, there were no significant differences in jejunum length, ileum length, and the whole digestive tract length and weight, the evidence showed that feeding habits still play a great role in the whole intestine. It is concluded that different staple feeding habits allow the birds to evolve different traits both in appearance and intestine, which aim to improve their predation rate and adapt to different environments. Among all features, duodenum and duodenal were the major objects to get stressed in digestive system, while beak length, wing length and tail length differed most in appearance. And it was speculated that different food compositions lead to different changes in certain positions of the body, thus might shape an explorable trail, which needs to be investigated thoroughly.

摘要 本研究针对主食摄食模式一致的两种鸟类——白腰文鸟（Lonchura striata）与鹊鸲（Copsychus saularis）的外观形态与消化系统差异展开探索。所有实验个体均经野外自然捕捉后以合规方式实施安乐死，随后对其喙（bill）、十二指肠（duodenum）、空肠（jejunum）、回肠（ileum）以及嘴峰（Culmen）、爪（Claw）、翼（Wing）、跗跖（Tarsus）、趾（Toe）、尾（Tail）等躯体部位的形态进行观测。研究结果显示，二者在外观特征上的喙长、翼长及尾长存在显著差异，且该差异与其主食摄食习性相关。此外，消化系统层面的十二指肠长度及十二指肠指数均呈现显著差异（P<0.05或P<0.01），该差异被认为与其捕食率相关；但二者的空肠长度、回肠长度以及整个消化道的长度与重量均无显著差异，这表明摄食习性对整体肠道仍发挥着重要作用。综上，不同的主食摄食习性促使这两种鸟类在外观及肠道结构上演化出差异化特征，以提升其捕食效率并适应不同生存环境。在所有观测特征中，十二指肠及十二指肠相关指标为消化系统中受影响最为显著的部分，而喙长、翼长及尾长则是外观特征中差异最突出的指标。据此推测，不同的食物组成会导致躯体特定部位产生差异化变化，或可开辟一条可供深入挖掘的研究路径，有待开展进一步的系统性探究。