Geographic Variation In The Skull Of The Siberian Weasel(Mustela Sibirica Manchurica) Among Different Ecotypes

Skull shape is in animals to adapt to the environment in the process of formation of the relatively stable characteristics,is revealed interspecific and intraspecific effective means of evolution.Through the different geographical environment skull morphological variation, and building that can meet the needs of its function characteristics of the relationship between the importance of species is the study of adaptive evolution process.This study in forest area of Lesser Khingan Range and songnen plain acquisition weasel northeast subspecies respectively forest ecological and ecotype of male and female adult skulls. By using an electronic caliper (accurate to 0.01mm) 16 morphological indicators measured as follows:Profile length、Basal length、Median palatal hength、Base palatal length, BPL、Least breadth between the orbits、Greatest frontal breadth、Zygomatic breadth、Greatest breadth of snout、Greatest diameter of the tympanic bulla、Greatest width of the tympanic bulla、Greatest neurocranium breadth、 Height of the foramen magnum、Oral length of the vertical ramus、Oral height of the vertical ramus、 Canine teeth length of maxillary. Canine teeth length of submaxill. By SPSS statistical analysis software on forest ecosystems, plain ecosystems skull specimens collected were identified and data measurement and analysis functions. The following findings:l.The plain ecological weasel skull were greater than the indicators of ecological forest;2.The sexual dimorphism characteristic of weasel skull is obvious. Two ecotypes of male weasel skull shape each index of indicators were greater than the female.The results show that, Weasel northeast subspecies of two different ecotype skull morphological changes related to the scope of animal feeding, home domain, drive the weasel geographic variation may be linked to the main factors of shape and structure of the skull foraging habitat in various ecological factors are closely related. Through the same subspecies different ecotype variation of shape and structure of the skull differentiation, shows that weasel with high adaptability to the environment changes.