Meeting Abstract
Birds constitute a classic example of modern vertebrates with highly variable neck lengths ranging from short necks in songbirds to extremely long, serpentine necks in herons. Since this includes a wide array of small to very large species, this raises the question of how neck length relates to body size. Furthermore, neck length is not necessarily an indicator of the number of cervical vertebrae since a few elongated vertebrae may form an equally long neck as do many short vertebrae. Despite their long necks, the long-legged flamingos have only 19 cervical vertebrae, whereas the necks of the short-legged swans display 26 cervical vertebrae. This leads to the second question of whether there is a relation between the length of cervical vertebrae and other parts of the body. Here, we sampled the mounted skeletons of a diversity of bird species (N=82) and compiled quantitative data of body proportions. We tested the length of the cervical vertebrae in relation to body size in order to reveal if the avian neck is subject to allometry. The estimators of body size include body mass and femur length. Next, we analyzed the relationship between vertebral length and the length of other body parts such as skull, trunk, and pelvic limb bones. This enables to reveal trends in proportion between the neck and other parts of the skeleton. In addition to vertebral morphology, vertebral number and size affect the motion and hence function of the avian neck. The present study, as the first large scale analysis of the scaling patterns of the cervical vertebral column in birds, provides an important basis for future work investigating the biomechanical consequences of these factors.
