Variability of skull morphometric characters in Nycetereutes procyonoides

Abstract

The raccoon dog (Nyctereutes procyonoides) is a medium-sized carnivore which spread over Eastern, Central and Northern Europe after its introduction into the European part of the former Soviet Union. The aim of the present study was to perform osteometrical analysis on Tadas Ivanauskas Zoological Museum specimens of raccoon dogs skulls collected in 1957, and compare the results of analysis with those obtained in 2005 in Lithuania and with osteometrical parameters from aboriginal Amur and Khabarovsk populations. In total, 36 skulls of raccoon dogs (20 males and 16 females) were used to examine any variations of skull morphometric characteristics with respect to sex. In total, 7 measurements were taken on each skull of the raccoon dog. The results of the analysis showed that males were larger than females and indicated some differences among raccoon dog skulls collected in different regions of Lithuania. The maximum condylobasal length of the Nyctereutes procyonoides found in 1957 and 2007 Lithuanian populations was larger than in aboriginal populations (Korablev et al., 2013). The mean values of measurements on interorbital constriction (IC), postorbital constriction (PC) and mandible height of skulls in the present study were lower that reported in specimens from the native range of the raccoon dog. The results of comparison analysis revealed higher value of index of raccoon dog skulls in males from Amur, while the lowest indices were observed in specimens from Khabarovsk and Lithuania.