Computed Tomography as a Method for Age Determination of Carnivora and Odontocetes with Validation from Individuals with Known Age

• Published in: Animals
• Main Authors: Sina Baier-Stegmaier, Carsten Gundlach, Mariann Chriél, Mette Sif Hansen, Christina Vedel-Smith, Charlotte Vikkelsø Hansen, Daniel Klingberg Johansson, Louise Birgitte Henriksen, Magnus Wahlberg, Charlotte Bie Thøstesen, Aage Kristian Olsen Alstrup, Kristian Murphy Gregersen, Cino Pertoldi, Sussie Pagh
• Format: Text
• Language: English
• Published: Multidisciplinary Digital Publishing Institute 2023
• Subjects: museum collections; X-ray; computed tomography; micro-CT; µ-CT; toothed whale age; carnivore age; red fox; Vulpes vulpes; American mink; Neogale vison; harbor porpoise; Phocoena phocoena; toothed whale
• Online Access: https://doi.org/10.3390/ani13111783

Traditional methods for age determination of wildlife include either slicing thin sections off or grinding a tooth, both of which are laborious and invasive. Especially when it comes to ancient and valuable museum samples of rare or extinct species, non-invasive methods are preferable. In this study, X-ray micro-computed tomography (µ-CT) was verified as an alternative non-invasive method for age determination of three species within the order of Carnivora and suborders Odontoceti. Teeth from 13 red foxes (Vulpes vulpes), 2 American mink (Neogale vison), and 2 harbor porpoises (Phocoena phocoena) of known age were studied using µ-CT. The number of visible dental growth layers in the µ-CT were highly correlated with true age for all three species (R2 = 96%, p < 0.001). In addition, the Bland–Altman plot showed high agreement between the age of individuals and visible dental layers represented in 2D slices of the 3D µ-CT images. The true age of individuals was on average 0.3 (±0.6 SD) years higher than the age interpreted by the µ-CT image, and there was a 95% agreement between the true age and the age interpreted from visible dental layers in the µ-CT.