Pair-bonding and parental care in cricetid rodents: a comparative study

Abstract

The cricetid rodents (hamsters, voles, and gerbils) show substantial inter-specific variation in their social organization, mating strategies, and patterns of social behavior, including parental care. In the present study, behaviors related to pair-bonding and parental activities were evaluated in male–female pairs of six cricetid species (Cricetulus migratorius Pallas, 1773, Clethrionomys rutilus Pallas, 1779, Microtus arvalis Pallas, 1778, Microtus socialis Pallas, 1773, Lasiopodomys brandti Radde, 1852, and Meriones unguiculatus Milne-Edwards, 1867) observed under laboratory conditions. These species were chosen due to particular differences in their mating strategies and the spatial-and-ethological population structure (Types I–IV). The results of the study show that there is a pronounced tendency towards both reinforcement of pair-bonds and increasing rate of direct parental care, especially paternal one, when solitary or gregarious species (Types I and II—C. migratorius and C. rutilus) are compared with the ones living in family groups (Type III—M. arvalis and M. socialis and Type IV—L. brandti and M. unguiculatus). Parental investment of males is mainly related to additional tactile stimulation of infants. A high level of tactile stimulation of pups promotes an increase in subsequent paternal care and reinforcement of pair-bonding, and, conversely, a deficit of tactile stimulation negatively affects the development of paternal behavior and social relationships. Thus, tactile stimulation can be regarded as one of the proximate mechanisms of socialization that plays an essential role in the evolution of sociality, i.e., transition to a family-group mode of life in rodents.