3D Insights into the Effects of Captivity on Wolf Mastication and Their Tooth Marks; Implications in Ecological Studies of Both the Past and Present

Abstract

Human populations have been known to develop complex relationships with large carnivore species throughout time, with evidence of both competition and collaboration to obtain resources throughout the Pleistocene. From this perspective, many archaeological and palaeontological sites present evidence of carnivore modifications to bone. In response to this, specialists in the study of microscopic bone surface modifications have resorted to the use of 3D modeling and data science techniques for the inspection of these elements, reaching novel limits for the discerning of carnivore agencies. The present research analyzes the tooth mark variability produced by multiple Iberian wolf individuals, with the aim of studying how captivity may affect the nature of tooth marks left on bone. In addition to this, four different populations of both wild and captive Iberian wolves are also compared for a more in-depth comparison of intra-species variability. This research statistically shows that large canid tooth pits are the least affected by captivity, while tooth scores appear more superficial when produced by captive wolves. The superficial nature of captive wolf tooth scores is additionally seen to correlate with other metric features, thus influencing overall mark morphologies. In light of this, the present study opens a new dialogue on the reasons behind this, advising caution when using tooth scores for carnivore identification and contemplating how elements such as stress may be affecting the wolves under study.

New Geometric Morphometric Insights in Digital Taphonomy: Analyses into the Sexual Dimorphism of Felids through Their Tooth Pits

“…A recent study by Toledo et al [26] revealed metric differences in the bite of female and male wolves on dental wax, while noting metric differences mainly in the size of male and female wolf teeth. While other studies have not yet noticed whether sexual dimorphism has an effect on the tooth marks produced [21,22], the sex of these individuals have not been directly observed. The present study considers the possible differences that may be produced by sexual dimorphism, specifically among felid individuals.…”

“…In each of the aforementioned analyses, observations made by authors tend to agree that intraspecific variability from different populations are less likely to affect tooth pits [21,22], at least in the case of wolves. To continue with this line of research, however, it is important that these results be observed equally in other carnivore families, such as felids, to extrapolate information on a larger scale.…”

“…Since these advances, multiple efforts have been made to increase the resolution of these different approaches, with the added benefit of using computational learning approaches to process such information [3,[18][19][20][21][22]. In some of these cases, studies have been able to reach a resolution of correctly identifying the carnivore producing tooth marks with up to >90% accuracy based on their shape and size.…”

“…Within this line of research, however, a number of questions still remain regarding possible conditioning variables that may distort these results. From this perspective, intraspecific analyses are becoming increasingly important, such as (1) the comparison of tooth marks found on different sized animals [19]; (2) possible intraspecific variability influenced by multiple individuals [22]; (3) or the reliability of experimental samples obtained by animals in captivity or in the wild [22]. In each of these cases, these kinds of queries are valuable since almost all tooth mark-related research is carried out on specific groups of individuals, without taking into consideration the possible variations that may occur when sampling from other populations.…”

“…In the case where intraspecific variability is a considerable factor, then extrapolation to larger studies is much more difficult. Likewise, most tooth mark samples are developed on preys of a certain size, while animals in captivity have been observed to present different behavioral attributes to wild animals [23][24][25], thus affecting their tooth mark morphologies [22].…”