1. Orientation with respect to the sun has been observed in a wide range of species and has generally been interpreted in terms of thermoregulation and/or ultraviolet (UV) protection. For countershaded animals, orientation with respect to the sun may also result from the pressure to exploit the gradient of coloration optimally to enhance crypsis. 2. Here, we use computational modelling to predict the optimal countershading pattern for an oriented body. We assess how camouflage performance...

This dataset comprises cast reconstructions of brain cavity space in 60 extant avian species, derived from X-ray micro computed-tomography scan image stacks. Each reconstruction was made using Materialise Mimics 14.11 to create volumetric models (brain cavity casts) that were then transformed into the polygon mesh stereolithograph (STL) files archived here. Brain cavity cast models are in most cases accompanied by casts of main vascular features (e.g., carotid arteries) and the olfactory nerves (CN I). A...