Behavior of Arvalis and Obscurus chromosomal forms of common vole (Microtus arvalis Pallas, 1779) males in the Partition test

Abstract

To compare the social and individual behaviors of common vole (Microtus arvalis Pallas, 1779) chromosomal forms («arvalis» and «obscurus») the Partition test was performed using different compositions of opponents (conspecific or heterospecific). Tests were performed in «arvalis» and «obscurus» males kept in animal facilities of the Zoological Institute (St. Petersburg, Russia). Laboratory populations originate from animals caught in the hybrid zone of these chromosome forms of voles (Vladimir region). Independent groups of animals were used for test with conspecific (N=28 for «arvalis» form; N=32 for «obscurus» form) and/or heterospecific (N=31 for both chromosomal forms) opponent. Test duration – 10 min. The behavior of animals (consequence and duration of behavioral elements) was registered by video films with special computer program «Ethograph» (ver. 2.07, RITEC, Russia). It was established that locomotor activity was greater in «obscurus» males. The level of anxiety estimated by amount of fecal boluses was higher in «arvalis» males. There were no differences in aggressive behavior of vole’s chromosomal forms, though both «arvalis» and «obscurus» were more aggressive towards individuals of heterospecific chromosomal form. The results of the present study confirm our previously published assumption about different behavioral strategies of common vole’s chromosomal forms: active-offensive for «obscurus» and passive avoidance (hiding behavior) for «arvalis».