A recent paper highlights the differences in shape between captive and wild big cat skulls. The nature of shape change found indicates that it is the mechanical influences of diet that have affected skull and mandible development.
Lion and tiger specimens at National Museums Scotland, which includes an extensive collection of skulls and mandibles from zoos, were vital for analysing patterns of variation between captive and wild big cats, and why these differences have occurred.
The skulls and mandibles of wild lions and tigers are impacted by higher mechanical stresses during life due to the additional demands of capturing, manipulating and consuming large prey. Some parts of the skull are constrained by increased muscle mass, and greater direct forces acting upon the skull, whilst sites of muscle attachment are increased due to pulling forces.
Most captive big cats used in the study are from European institutions and span the last 150 years. These cats will have been fed partial or whole carcasses, which better replicate the mechanical properties of wild diets than softer prepared diets. The authors including Dr David Cooper and Dr Andrew Kitchener speculate that additional mechanical stresses upon the skull and mandible such as the killing bite, manipulation such as dragging, and consumption of large prey in the wild have driven the shape differentiation between the skulls of captive and wild big cats.
Photo by Thomas Evans on Unsplash
It is important to understand these differences to better care for captive animals, enhance their survival in reintroduction, and to understand the importance of environmental factors in influencing an animal’s size or shape.
The original article is available here: https://www.mdpi.com/2076-2615/13/23/3616#