Time investment in reproduction by female Japanese giant flying squirrel (Petaurista leucogenys)

To study female behavior during breeding, we set up three nest boxes equipped with a camera box in the suburban forests of Hachioji, Tokyo, Japan and recorded their behavior. We recorded 10 cases of breeding during 3549 days from February 2010 to May 2014. Females gave birth in two peaks, from February to March, and from June to September. The average litter size was 1.3 individuals. In three out of 10 cases, pups grew until they went out from the nests, and in three cases they were predated upon by a snake and a marten. Reproductive success for the remaining four cases were unknown due to reasons such as nest movement. Females stayed in the nest for most of the time till a few days after birth. As the pup grew, the time spent outside the nest increased. The activity patterns of females in rearing pups differed among individuals. Females and their offspring stayed together until 229 days of age of the pup at the longest. It was suggested that time investment for breeding was higher in female Japanese giant flying squirrels than in other species of Sciuridae.