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In a study of gerbils with contrasting social and mating systems (group-living monogamous Mongolian gerbil Meriones unguiculatus , solitary nonterritorial promiscuous midday jird M. meridianus , and solitary territorial promiscuous pale gerbil Gerbillus perpallidus), we employed partner preference tests (PPTs) to assess among-species variation in sociability and pair-bonding patterns and tested whether the nature of contact between individuals: direct contact (DC) versus nondirect contact (NDC) affected our results. We measured male preferences as the time: 1) spent alone, 2) with familiar (partner), and 3) unfamiliar (stranger) female in the 3-chambered apparatus. Gerbil species differed strongly in sociability and male partner preferences. The time spent alone was a reliable indicator of species sociability independent of the nature of contact, whereas the pattern and level of between-species differences in male partner preferences depended on contact type: DC PPTs, unlike NDC-tests, discriminated well between monogamous and promiscuous species. In the DC-tests, stranger-directed aggression and stranger avoidance were observed both in the highly social monogamous M. unguiculatus and the solitary territorial promiscuous G. perpallidus , but not in the nonterritorial promiscuous M. meridianus. In M. unguiculatus , stranger avoidance in the DC-tests increased the time spent with the partner, thus providing evidence of a partner preference that was not found in the NDC-tests, whereas in G. perpallidus , stranger avoidance increased the time spent alone. This first comparative experimental study of partner preferences in gerbils provides new insights into the interspecific variation in gerbil sociality and mating systems and sheds light on behavioral mechanisms underlying social fidelity and pair-bonding. [ABSTRACT FROM AUTHOR]

The speckled ground squirrel, Spermophilus suslicus (Güldenstead, 1770) was formerly a widely distributed species in eastern Europe, and it was even considered a pest species. The distribution range of the speckled ground squirrel is now fragmented, most of its settlements are small and separated from each other. This tendency is observed over most of the species' range. At present, the speckled ground squirrel usually inhabits areas difficult to plough, hills, gullies and lows, often situated on the banks of different water management facilities. Last significant decrease of the species' numbers occurred at the end of the 20th century. However, in recent years a slight tendency to population increase has been observed in some regions. The main causes of the decline are climatic factors -- cold end little-snow winters, spring and summer droughts, or increase of humidity. Further threats are changes in land use and habitat fragmentation that, together with applicatication of pesticides and other toxic chemicals, lead to isolation and decrease in the number of settlements. The current state of the speckled ground squirrel can be characterised as unsatisfactory and unstable. To be preserved, this species undoubtedly needs special conservation actions. [ABSTRACT FROM AUTHOR]