2010/09/01 by Andrew N. Iwaniuk, Christopher P. Heesy, Margaret Hall · 2 citations
Earth and Planetary Sciences · Environmental Science · Neuroscience · #Paleontology and Evolutionary Biology #Amphibian and Reptile Biology #Avian ecology and behavior #Nocturnal #Biology #Anatomy #Cornea #Orbit (dynamics) #Zoology #Ecology #Neuroscience
paper · doi:10.1139/z10-051
openalex publication_date 2010/09/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
The Swallow-tailed Gull ( Creagrus furcatus (Neboux, 1846)) is known for its nocturnal feeding habits and apparently large eyes. Despite frequent observations of its large eyes, detailed measurements of its eyes and orbits are wanting. Here, we provide a detailed analysis of the size and shape of the eye and orbits of this unique species in relation to a range of other gull species. Although the C. furcatus does have a slightly enlarged cornea and optical axis, neither the transverse orbit diameter nor the shape of its eye differs significantly from other larids. In addition, we found no significant difference between C. furcatus and other gulls in terms of its orbit dimensions and orbit orientation. We therefore conclude that C. furcatus does not possess a transversely enlarged eye, but rather a slightly larger cornea and longer eye. Our results do not, however, preclude the presence of other changes in the visual system, such as retinal morphology or neurophysiology, that could be adaptive for nocturnal feeding.