1. Accurately quantifying the shape of birds' eggs
- Author
-
Tim R. Birkhead, Jamie E. Thompson, and John D. Biggins
- Subjects
0106 biological sciences ,Ecology ,business.industry ,Pattern recognition ,elongation ,pyriform ,010603 evolutionary biology ,01 natural sciences ,pointedness ,Bird egg ,010605 ornithology ,shape parameters ,shape indices ,Range (statistics) ,Artificial intelligence ,business ,Ecology, Evolution, Behavior and Systematics ,asymmetry ,Nature and Landscape Conservation ,Mathematics ,Original Research ,guillemot - Abstract
Describing the range of avian egg shapes quantitatively has long been recognized as difficult. A variety of approaches has been adopted, some of which aim to capture the shape accurately and some to provide intelligible indices of shape. The objectives here are to show that a (four‐parameter) method proposed by Preston (1953, The Auk, 70, 160) is the best option for quantifying egg shape, to provide and document an R program for applying this method to suitable photographs of eggs, to illustrate that intelligible shape indices can be derived from the summary this method provides, to review shape indices that have been proposed, and to report on the errors introduced using photographs of eggs at rest rather than horizontal.
- Published
- 2018