Skeletal injuries in small mammals: a multispecies assessment of prevalence and location

Abstract

Wild mammals are known to survive injuries that result in skeletal abnormalities. Quantifying and comparing skeletal injuries among species can provide insight into the factors that cause skeletal injuries and enable survival following an injury. We documented the prevalence and location of structural bone abnormalities in a community of 7 small mammal species inhabiting the White Mountains of New Hampshire. These species differ in locomotion type and levels of intraspecific aggression. Overall, the majority of injuries were to the ribs or caudal vertebrae. Incidence of skeletal injuries was highest in older animals, indicating that injuries accumulate over a lifetime. Compared to species with ambulatory locomotion, those with more specialized (semi-fossorial, saltatorial, and scansorial) locomotion exhibited fewer skeletal abnormalities in the arms and legs, which we hypothesize is a result of a lesser ability to survive limb injuries. Patterns of skeletal injuries in shrews (Soricidae) were consistent with intraspecific aggression, particularly in males, whereas skeletal injuries in rodents (Rodentia) were more likely accidental or resulting from interactions with predators. Our results demonstrate that both the incidence and pattern of skeletal injuries vary by species and suggest that the ability of an individual to survive a specific skeletal injury depends on its severity and location as well as the locomotor mode of the species involved.