Behavior of Mound-Building Mouse, Mus Spicilegus During Autumn-Winter Period in Captivity

ABSTRACT

Mus spicilegus is an outdoor species from southern-eastern Europe, adapted to agroecosystems. In the beginning of autumn, to spend the winter, mound-building mice build complex mounds. These mounds are built using accumulation of seeds covered with earth. This behavior is unique among mice species. However, there is evidence that at higher temperatures and a larger availability of food in winter, mice can optimize this particular behavior in direction to simpler constructions or even not build them at all. To clarify if mice display building activity under laboratory conditions we studied behavior of M. spicilegus in 5 intraspecific cage groups during autumn-winter period. The observations were carried out in 100 × 100 cm glass cages provided with earth and sawdust as bedding and straw and hay as nesting material. The groups were formed by 3–4 mice captured from a wild population in northern Bulgaria in early September of 2008, where mounds were already built. Mice were grouped according to the mound they belong to. The results showed that mound-building mice display high level of building activity, especially in the first month of their time in the laboratory. In majority of groups mice built domed nests made from straw and hay, where they lived together. Seeds in the cages were covered with earth, as far as that was possible. However, mice in some groups made burrows of simple design. Based on these findings it could be assumed that building behavior of M. spicilegus is genetically determined, but as microtine rodents M. spicilegus can be quite flexible in employing behavior to suit the local environment.

Keywords:

• building behavior
• intraspecific cage groups
• Mus spicilegus
• nest design
• time budget