Biomechanical evaluation of the upper beak of Neotropical birds

Abstract

Understanding the mechanical forces acting on the beak is crucial to enhancing the management of maxillary beak avulsion cases. Therefore, this study aimed to biomechanically evaluate the upper beaks of five Neotropical bird species and analyze Hounsfield units (HU) values using computed tomography (CT). Analysis was performed on white-eyed parakeet Psittacara leucophthalmus, red-legged seriema Cariama cristata, black-headed vulture Coragyps atratus, buff-necked ibis Theristicus caudatus, and toco toucan Ramphastos toco. A mechanical bending test was performed with a load applied perpendicularly to the distal third of the maxillary rostrum in the ventrodorsal direction. HU values were determined at three points of interest in the same area where the actuator was applied. There were no statistical differences in the HU values between parakeet and seriema beaks, while all other bird species exhibited statistical differences. The maximum force was highest for the parakeet (682.2 N) and toco toucan (126.6 N) beaks, followed by the seriema (65.3 N) and black-headed vulture (57.6 N), with the buff-necked ibis having the lowest force (21.2 N). Statistical analysis revealed differences in maximum force between the parakeet’s beak and those of all other species. Significant differences occurred in maximum deformation between the black-headed vulture and buff-necked ibis beaks, and between the seriema and buff-necked ibis beaks. Statistical differences were also observed in the moment of the toco toucan’s beak compared to the other bird’s beaks. In conclusion, the data obtained may support future studies on prosthetic materials for the species analysed, taking into account the differences identified through the mechanical test.