Volumetric and Volume Fractional Comparison of the Nasal Structures of the Stork (Ciconia ciconia) and Seagull (Larus fuscus) Using Computed Tomography Images

Abstract

The rostral part of the nasal cavity is cooler to prevent the loss of water that is crucial for the fluid balance of birds. This function may be related to the structure of the nose of flying birds. For this reason, we decided to analyze the nasal structure of two different birds using volume and volume fraction approach of the stereology. In this study, 14 seagulls and 7 storks were examined and volume fractions of the nasal cavity and nasal structures were estimated. Heads of animals were scanned in computed tomography. The images were sampled randomly at a 1/5 sampling fraction. 11-16 sections for the stork and 16-20 sections for the seagull were examined. The sectional surface areas of the total nasal cavity, nasal septum, nasal space and conchae were estimated using the Cavalieri principle of the stereological methods. The volume and volume fractions of structures were assessed. Results obtained from the CT images were compared between stork and seagull. The volume fractions of the conchae, nasal cavity and nasal septum were 30.24%, 55.22%, 14.54%, and 33.03%, 53.23%, 13.73%, in stork and seagulls, respectively. The volume fractions of structures did not show statistical difference between two species. Our findings suggest that the nasal structures of the two-different species have similar architecture, which may be linked to the same function in flying birds.