Comparative craniometric measurements of two Canid species in Egypt: the Egyptian red fox and the Egyptian Baladi dog

The Egyptian red fox (Vulpes vulpes aegyptiaca) and Egyptian Baladi dog (Canis familiaris) are two members of the Family Canidae that are widely distributed in Egypt. The skulls of different Canid species vary greatly in their size and shape; therefore, they can be used as a tool to study the evolution and evolutionary history of these animals. The craniometric measurements are crucial for species identification and determination of the specific sites for nerve blocks. The present study compared the craniometric measurements of the red fox and Baladi dog skulls by measuring 47 parameters on each skull and calculation of 8 indices. The red fox skull had significantly lower values of 41 craniometric measurements (approximately 87% of the measurements done), including skull length, width, and height, cranial length and width, palatal and mandibular length, and dental measurements. In contrast, the red fox had significantly higher values of only 3 measurements (approximately 6% of the measurements done) including the tympanic bulla measurement. While only three skull measurements did not differ significantly between the red fox and dog. Statistics revealed that domestic dog had significantly higher values of foramen magnum and palatine indices, and significantly lower value of nasal index than those of red fox. The present work reported variations in the gross and craniometric measurements of skull between the red fox and dog. The measured cranial parameters of both adult animals provide valuable information that can be used in ecological studies, comparative anatomy, and clinical veterinary sciences.

Morphometric analysis of the red fox molar teeth in Lithuania

The objective of the study was to investigate the lengths and widths of maxillary (P⁴ , M¹ and M² ) and mandibular (M₁ , M₂ and M₃ ) molar teeth, lengths of dental rows and dental features of sexual dimorphism in the red fox. The correlation analysis between teeth measurements and dental row length was included too. The osteometric analysis was performed by the A. von den Driesch (1976) method. A total of 230 skulls and mandibles were investigated (n = 230): 113 males (n = 113) and 117 females (n = 117). The findings of the research revealed that most dimensions are higher in males compared with females (p < 0.001). Contrarily, Wilks' Lambda analysis showed results in the interval from 0.821 to 1, which leads to the conclusion that a teeth measurement study is unreliable to determine the sex of the red fox. The trustworthy measurements were the length of the whole dental arcade in the maxilla and mandible (UDR and LDR); Wilks' Lambda UDR = 0.860; LDR = 0.821; p < 0.001). Evaluation of the correlation between measurements revealed that results vary from very weak (0.047) to moderate strength (0.543). There were no strongly correlating measurements found. The correlation between the upper and lower molars with the length of the teeth arcade is quite weak, and only solitary measurements (M² , L and B) had a weak correlation.

Distinct features of intraspecific and intrapopulation variability of the skull size in the red fox

The range of chronographic variability of the average size of the skull in the red fox (data collected by the authors) from a compact area in the Middle Urals has been assessed for a 30-year period, and the results obtained have been compared with the published data on the geographical variability within the vast species range. The range of changes of the average dimensions of the skull over time spanned almost the entire range of geographical variability. Therefore, the problem of search for factors that determine the morphological diversity arises.