Geographic variation in skull shape of the water shrew, Neomys anomalus (Cabrera, 1907) in Slovenia

Namen raziskave je bil analizirati geografsko variabilnost lobanje močvirske rovke Neomys anomalus v Sloveniji. Predstavnike močvirske rovke najpogosteje najdemo ob stoječih vodnih telesih. V Sloveniji je splošno razširjena, saj jo najdemo od nižin do visokogorja. V tej raziskavi smo domnevali, da se selekcijski pritiski razlikujejo med okolji, kar se odraža kot medpopulacijska morfometrična heterogenost. Geografsko variabilnost močvirske rovke smo merili na lobanjah, pridobljenih iz muzejskih zbirk Prirodoslovnega muzeja Slovenije. V analizo smo vključili 164 osebkov s petih geografskih območij (Kočevja, Kranja, Lendave, Ljubljanskega barja in Postojne). Z metodami geometrijske morfometrije smo ovrednotili variabilnost v velikosti in obliko lobanj. Dokazali smo, da med različnimi geografskimi območji obstajajo statistično značilne razlike tako v velikosti kot obliki lobanje. Na splošno sekundarni spolni dimorfizem ni bil statistično značilen ne v velikosti in ne obliki lobanje. Izjema so samice z Ljubljanskega barja, ki so imele nekoliko večje lobanje. Velikost osebkov se je večala od severa proti jugu in je bila v negativni korelaciji s povprečno temperaturo okolja ter je tako izkazovala pozitiven Bergmannov odziv. Odkrili smo, da sta za območji z največjimi (Postojna) in najmanjšimi lobanjami (Lendava) bili značilni tudi skrajni nadmorski višini (556 m in 161 m). Odkrili smo tudi, da se variabilnost v velikosti lobanje močvirske rovke v Sloveniji ujema z ugotovitvami, da so osebki močvirske rovke manjši v območjih, kjer živijo simpatrično z vodno rovko Neomys fodiens.The aim of the research was to determine the geographical variation of the skull shape of the Mediterranean water shrew Neomys anomalus in Slovenia. Representatives of the Neomys anomalus are most often found near different bodies of water. They are widely spread throughout Slovenia as they can be found in the lowlands as well as in the highlands. In this paper, we assumed that the selection pressures are different in different environments, which is reflected in interpopulation morphometric heterogeneity. The geographical variation of the Neomys anomalus was measured on skulls obtained from the museum collections of the Museum of Natural History. In our analysis, we included 164 specimens from five geographical areas (Kočevje, Kranj, Lendava, the Ljubljana Marshes, and Postojna). With the geometric morphometrics methods, we evaluated the variability in size and shape of the skulls. The results have shown that statistically significant differences can be observed in different geographical areas in both size and shape of the skull. In general, secondary sexual dimorphism was not statistically significant in size and in shape of the skulls. Exceptions are females from the Ljubljana Marshes, which had slightly larger skulls. The size of the specimens increased from north to south and was in a negative correlation with the average temperature and thus showed a positive Bergmann’s response. We learned that in areas with the largest (Postojna) and the smallest (Lendava) skulls extreme altitudes (556 m and 161 m respectively) also played an important part. We concluded that the variability in the size of the skulls of the Neomys anomalus in Slovenia coincided with the existing findings that the specimens of the Neomys anomalus were smaller in areas where they live sympatrically with the Eurasian water shrew Neomys fodiens