Factors affecting the harem formation process by young Misaki feral stallions

For the past 12 years, a study was conducted in the Misaki area (southern K yushu Island, Japan) to investigate young males form new harems, how they a cquire the mares and the factors affecting the process of new harem formati on. Young males formed new harems between the ages of 3.8 and 7.6 yr, and 9 3% of these new harem groups were formed at the beginning of the breeding s eason. The most common way (87%) for young males to form a new harem was by acquiring wandering mares which had separated from their groups, whereas 1 3% stole unstable mares from established bands. The fact that all young mal es obtained harems the new at an early age, with an average age of 5.2 yr ( n=15) could be explained high female biased sex ratio (3:1), and great numb er of wandering mares per stallion (2.5:1). At the time new harem groups we re formed, aggression, fighting or such behavior as active herding or drivi ng mares was not observed among stallions because the "unstable" mares were most likely to be abducted by stallions.