Morphometrics of a wild Asian elephant exhibiting disproportionate dwarfism

Abstract

Dwarfism is a condition characterized by shorter stature, at times accompanied by differential skeletal growth pro-portions relative to the species-typical physical conformation. Causes vary and well-documented in humans as well as certain mammalian species in captive or laboratory conditions, but rarely observed in the wild. Here we report on a single case of apparent dwarfism in a free-ranging adult male Asian elephant (Elephas maximus) in Sri Lanka, comparing physical dimensions to those of other males in the same population, males in other populations, and records in previous literature. The subject was found to have a shoulder height of approximately 195cm, is shorter than the average height of typical mature males, with a body length of 218cm. This ratio of body length to height deviates from what is typically observed, which is approximately 1:1. In absolute height the subject was similar to the attributes of a captive elephant documented in 1955 in Sri Lanka, also said to be a dwarf, however the two specimens differed in the relative proportions of height vs. body length. The subject also exhibits a slight elongation of the skull. We discuss how this phenotype compares to cases of dwarfism in other non-human animals.