The pattern of play behaviors in white-headed langurs from 1 to 12
months old in limestone forests, southwest China
Abstract
Play behavior is a significant trait of immature nonhuman primates
(hereafter primates), which may play important roles in sensory,
locomotor, socio-cognitive, and developmental processes in primates. It
has been suggested that function of play is to practice and improve
motor skills related to foraging, avoiding predation, attracting mates,
raising offspring, and also is to strength social skills concerning to
cementing friendly relationships and defraying aggression among
individuals. From September 2009 to August 2010, we investigated play
behaviors of 1-12-month-old white-headed langur (Trachypithecus
leucocephalus) which is a critically endangered primate endemic to
China. During this study, we recorded 4,421 play bouts and 1,302 minutes
of play time of 7 infants in total. We found that infants had different
play behavior patterns at different ages. Specifically, non-social play
behaviors appeared at 1 month of age, social play behaviors at 2 months,
and all types of social and non-social play behaviors at 3 months. The
frequency and duration of non-social play peaked at 5 months and then
decreased, while social play appeared at 2 months and gradually
increased with age. Non-social play did not differ between the sexes,
whereas social play showed sex specificity, with higher frequency and
duration of social play in male infants than in female infants. In
addition, male and female white-headed langur infants appeared to prefer
the individuals of same sex as social playmates. In conclusion, we first
reported the pattern of play behavior of a critically endangered langur
aged 1 to 12 months though the sample size is small, our results suggest
they may have the adaptation of play behaviors in ages and sexes, which
may help them adapt to their habitat and social system.