some ecological aspects of the genus microtus schrank, 1798 (mammalia: rodentia) in northwest of iran

in order to study the ecology of the genius microtus schrank, 1798 (mammalia: rodentia) in nwof iran, three regions including salmas, marand, and moghan were selected. the number of active nests of m. socialis and m. aff. socialis (2n=54) were detected during spring and autumn. in this period, detection were made in three blocks of each location (each one 20×50m) with intervals of one week in 2008-2009. in each blocks, hole colony diameter, slop, length, distance from the other holes, number of rooms in the holes, shape of the tunnels and their connection to each other were measured in the block from the same colony. meteorological data of each location including temperature (ºc), humidity (%) and rainfall (mm) were obtained from meteorological stations. decrease in population was found in the first and second blocks of salmas from 2008 autumn to 2009, but an increase in population was observed after 2009 autumn to september 2010. in spite of appropriate weather conditions, it is agricultural controls that have probably caused changes in population size. the number of m. socialis nesting population in moghan was higher than salmas and marand. the average sizes of diameter and length of the holes were 47.7 mm and 510 mm, and the slope angle was 35.4° in marand. in salmas, the average for diameter, length of hole entry, and slope angle degrees were 43 mm, 498 mm and 29.5° respectively. in moghan, both types of the described colonies were observed.