Ethologal Studies On The Captive White-Headed Langur (Presbytis Leucocephalus) And Feeding Enrichment In Shanghai Zoological Park

As one of the global rarest and most endangered animals in China, the white-headed langur (Presbytis leucocephalus) only distributed in the north of Ming Jiang, South of Zuo Jiang, in Guangxi province. Because of several reasons, the habitats of this langur were seriously deteriorated and the distribution area shrank greatly. The population of white-headed langurs decreased sharply. In recent years, the rare langur has gained more attentions from worldwide. In the 19^th International Primate Protection of the General Assembly, 2009, the white-headed langur was listed as one of the top 25 most endangered primate species which need to be protected. Thus enhancing the protection and management of this langur is becoming particularly important.Six white-headed langurs aged varied 1-14 years old were observed from May to August, 2007 in Shanghai Zoological Park. During this period, we have done the individual identification and divided the behaviors into six typical patterns. And then, the designed feeding enrichment was conducted in Sep. 2007. The zoo-keepers told authors that F1 had been pregnant for at least one month. So we used the continuous recording method to observe F1 and gained the data of daily time budget to discuss the variation differences during the pregnant period. What's more, the cinematograph with infrared was used for recording a continuous cycle of 24-hour observing. All the behaviors were grouped into seven behavioral types according to physiology, i.e. resting, moving, feeding, grooming, scratching, playing and other behaviors.Main results and conclusions are as follows:1. Diurnal and nocturnal rhythmic behavior of the captive white-headed langurs in springResting, feeding and moving accounted for most part of diurnal behaviors exhibited by the langurs. In spring, the langurs might wake up at 4:00am and moved for an hour, and then back to rest until 5:30am or 6:00am in the morning in spring. After a day's activity, they prepared for sleeping at about 19:00pm in the evening. The diurnal activity began at about 6:00am and finished at 18:00pm or 18:30pm. Scratching occurred at all times during the day and night. No grooming behavior happened in the night.With the help of the infrared cinematograph, we could observe the nocturnal activity easily and found that langurs had four small moving peaks at 21:00pm, 0:30am, 3:00am and 4:30am and also had three scratching peaks at 22:30pm, 1:00am and 2:00am which meant that the langurs kept awake and alert during the long night. What's more, the female langurs were less active than male ones during daytime, but exhibited more active during the night. Those findings indicated that we should give the langurs a quiet environment which may let them sleep better.2. Daily time budget of the captive white-headed langursResting was the main daily behavior of the langur. What's more, the zoo-keeper only feed the animal twice per day while the langurs had three feeding peaks. The three feeding peak hours were 8:00am-10:00am, 14:30pm-15:30pm and 16:30pm-17:00pm respectively. During the last feeding peak, almost all the langurs foraged the plants from the outside of the cage. Grooming peaks appeared at 10:00am-11:00am and 13:00pm-14:00pm, which were contrasted to the feeding and resting behavior. Meanwhile, moving, scratching and playing displayed no obvious peak hours.3. Influence of feeding enrichment on daily behavioral rhythm of the white-headed langurs.The feeding enrichment had a positive influence on the behavioral repertoire and welfare of captive white-headed langurs by increasing the levels of natural behaviors exhibited, such as feeding, grooming and scratching and the daily time budget was adjusted which was closer to the wild state. Meanwhile, it's their nature to have the third Spontaneous feeding time. Resting behavior decreased significantly while feeding, grooming, and scratching behaviors increased significantly after the feeding experiment. No significant changes were found for the moving and playing behaviors. The langurs become more active, which is more similar to wild conditions, fit in with captive conditions, more compatibly and display a more vigorous outlook to visitors. 4. Daily behavioral rhythm of "pregnant" F1 during different monthsThe activity rhythm of F1 had significant differences among the different months. Resting, moving, feeding, scratching and playing behaviors were differed significantly among the seven months, especially between September and December. No significant variation was found in grooming behavior. Meanwhile, using the experience to determine whether an animal was pregnant is very difficult and the accuracy is low. The pregnancy test seems very limited and could not apply in this area. So we suggested trying other methods, such as B-scanner for pregnancy.