Effects of Captivity on the Morphology of the Insertion Sites of the Palmar Radiocarpal Ligaments in Hominoid Primates.

Aroa Casado,David Riba,Yasmina Avià,Juan Francisco Pastor,Miquel Llorente,Josep Maria Potau

doi:10.3390/ani11071856

Abstract

Simple SummaryIn this manuscript, we report the results of our 3D geometric morphometric analyses of the distal radial epiphysis in wild and captive gorillas, chimpanzees, and orangutans. We have identified significant differences in the insertion sites of the palmar radiocarpal ligaments between the wild and captive specimens of each species that are likely related to the locomotor behaviors developed in captivity. We believe that our study deals with a subject of great social impact in today’s world: the well-being of animals living in captivity, especially hominoid primates. Our findings provide novel information on the effect of captivity on the anatomy and locomotor behavior of hominoid primates. We trust that this information can be a basis for improving the artificial spaces where these captive primates live by increasing their available space and providing structures that more closely simulate their natural environment.The environmental conditions of captive hominoid primates can lead to modifications in several aspects of their behavior, including locomotion, which can then alter the morphological characteristics of certain anatomical regions, such as the knee or wrist. We have performed tridimensional geometric morphometrics (3D GM) analyses of the distal radial epiphysis in wild and captive gorillas, chimpanzees, and orangutans. Our objective was to study the morphology of the insertion sites of the palmar radiocarpal ligaments, since the anatomical characteristics of these insertion sites are closely related to the different types of locomotion of these hominoid primates. We have identified significant differences between the wild and captive specimens that are likely related to their different types of locomotion. Our results indicate that the habitat conditions of captive hominoid primates may cause them to modify their locomotor behavior, leading to a greater use of certain movements in captivity than in the wild and resulting in the anatomical changes we have observed. We suggest that creating more natural environments in zoological facilities could reduce the impact of these differences and also increase the well-being of primates raised in captive environments.

Highlights

Osteological studies of animals are generally carried out with specimens from reference collections, such as research centers and museums
The wild and captive Pongo pygmaeus and the wild Pan troglodytes were mainly located in the negative PC1 values, while the wild and captive Gorilla gorilla were mainly located in the positive values, and the captive Pan troglodytes were mainly located in an intermediate position between the positive and negative values
Our 3D GM analysis has identified morphological differences in the insertion sites of the palmar radiocarpal ligaments between wild and captive orangutans, chimpanzees, and gorillas. These differences suggest that conditions of captivity can lead to changes in the locomotor behavior of hominoid primates that can modify the anatomy of some regions of the postcranial skeleton, such as the wrist

Summary

Introduction

Osteological studies of animals are generally carried out with specimens from reference collections, such as research centers and museums. Many of these specimens come from zoos, which provide animals that have died from different causes. Other authors stressed the importance of developing species-typical and natural behaviors [20], called ethnological needs [21,22]. To achieve these behaviors, animals require complex environments and stimuli [23]. Social, sensory, and cognitive stimulation through environmental enrichment may increase behavioral opportunities and enhance welfare, becoming a key element in captive animal care and management [24,25]

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