IVth International Conference on Dormice (Rodentia, Gliridae)13 - 16 September 1999 EDÝRNE - TURKEY |
CRANIAL SEXUAL DIMORPHISM AND MICROGEOGRAPHICAL VARIABILITY OF FOREST DORMOUSE (DRYOMYS NITEDULA PAL.) IN BULGARIA
Markov, G.
Institute of Zoology, 1 Tzar Osvoboditel, 1000 Sofia, Bulgaria. E-mail: geomar@bgcict.acad.bg
The skull morphometrics of the Forest dormouse was examined and compared. Craniometric relationship in the Dryomys nitedula was studied on 55 adult specimens collected in the three main localities of the species in Bulgaria ? Central Balkan, Vitosha Mountain and the mountains in Southeastern Bulgaria. Samples were subject to analysis of sexual dimorphism and microgeographic criteria. The results revealed that the Forest dormouse possesses well-expressed sexual dimorphism of the cranial characters. A discriminate function which determines the sex of Forest dormouse individuals with high statistical significance (p=0.01) was work out on the basis of 48 craniometric characters analyzed.
Further the male and female samples of each Forest dormouse population were analyzed separately. The multiple comparative craniometric analysis revealed that:
1. The craniometric similarity between the Bulgarian Forest dormouse populations is better expressed in females that in males.
2. The craniometric similarity between the Forest dormouse populations follows common regularity in both sexes ? it is well expressed between the populations from Vitosha and those ones from the mountains in South-eastern Bulgaria, while the Central Balkan population exhibits certain specific craniometric detachment.
3. The craniometric characters of both male and female Forest dormouse individuals are microgeographically determined but maintain high craniometric similarity between the populations.
Probably the ecological differences appear to be the main reasons for distinct patterns of microgeographic variation found in Bulgarian Forest dormouse, despite their apparent morphologic similarity.