Parental care and time sharing in the Mongolian gerbil

The biparental care behaviour of the social Mongolian gerbil (Meriones ungu iculatus) was quantified from birth to weaning of the young under laborator y conditions. Nestbuilding, nest-residence, and retrieving of the offspring were measured. The behaviour of the parents was registered per video-obser vation on days 2, 5, 8, 13, and 20 after the birth of the young, each for 2 4 h. To obtain control data, we additionally observed all pairs for 24 h wi thout progeny. The objective of our study was to evaluate the paternal and maternal efforts in rearing the young and to focus on parental time sharing in the nest. The female made the greatest contribution to care since there was no patern al support in building of the litter-nest and retrieving of the young. Howe ver, both adults cooperated via their synchronized presence with the young (temporal coordination or time sharing in the nest). We suggest that via th is mutual behavioural synchronization the physiological strains of the fema le caused, e. g., by lactational hyperthermia are reduced.