CHARACTER DISPLACEMENT IN MANDIBLE SHAPE AND SIZE IN 2 SPECIES OF WATER SHREWS (NEOMYS, MAMMALIA, INSECTIVORA)

Landmark coordinates were digitized from images of mandibles of trappe d specimens of two species of water shrews (Neomys fodiens and Neomys anomalus, Mammalia: Insectivora), and unidentified mandibles from owl pellets collected in Hungary. Discriminant analyses based on variables describing size, affine and nonaffine shape changes were carried out using positively identified specimens as training sets. The results in dicate that the two species can be separated using both size and shape variables, but the best discrimination can be achieved by using both set of variables. The two species were found to be more different at l ocalities where they occur sympatrically. The more abundant Neomys ano malus is more stable in its characters, while the less abundant specie s, Neomys fodiens, appears to lessen competition by shifting its chara cters at localities where both species co-occur.