Individual Behavior Of Female Sumatran Orangutan (Pongo abelii L.) With Enclosure Management System In Siantar Zoo

. Sumatran orangutans (Pongoabelii L.) is an endangered species due to habitat destruction. Conservation strategies need to be done in preventing extinction of orangutans, such as ex-situ conservation in Siantar zoo. This study aims to determine the behavior of individual male orangutan at Siantar Zoo with a management system. The observatuons was conducted for 14 days in August with the Focal Animal Sampling method, data recorded using the Instantaneous method and descriptive data using the Open Ended interview technique. The results showed the overall frequency of individual male orangutan behavior were locomotion (33,43%), resting (27,36%), eating (25,24%), playing (9%), agonistic (3,64%), self care (0,83%) and pooping (0,5%). The behavior of individual male orangutan is influenced by the number of visitors, namely the locomotion behavior of the crowded visitor category (34,37%), medium (30,31%) and quiet (33,18%). The resting behavior of crowded visitor catego ry (25,02%), medium (28,19%) and quiet (27,44%). The eating behavior for crowded, medium and quiet categories was 25,96% ; 25,47% and 26,30%. The playing behavior in crowded, medium and quiet categories is 7,96% ; 7,71% ; 9,75%. Agonistic behavior in crowded categories (5,44%), medium (7,11%) and quiet ( 1,96%). Self-care behavior for crowded,medium and quiet categories was 0,64% ; 0,83% ; 0,88%. The pooping behavior in the crowded category is 0,59%, in the medium category is 0,38% and in the quiet category is 0,49%. Themanagement system for male orangutan at Siantar Zoo already has a fairly good and regular system. The cage management has met the minimum requirements and the male orangutan has a optimal body weight and has never been infected with a serious disease.


Introduction
Orangutans are the only great apes found in Asia, precisely on the islands of Sumatra and Kalimantan. In Sumatra, there are two species of orangutan, namely the Sumatran Orangutan (Pongo abelii) which is limited to the northern part of the island of Sumatra (Aceh and North Sumatra Province) [1], and the Tapanuli Orangutan (Pongo tapanuliensis) which is found in the forest. Batang Toru, while in the Kalimantan area there is only one species, namely Pongo pygmaeus [2].The population of the Sumatran orangutan (Pongo abelii) has decreased from year to year, the main cause being habitat destruction due to illegal logging, forest fires and poaching [3]. Based on data obtained in 2004 it was estimated that around 7,500 individuals [4] and in 2007 decreased to 6,667 individuals, of whom were in Gunung Leuser National Park (Suaq Balimbing, Ketambe, Tangkahan, Bukit Lawang, Sampan Getek, Rawa Singkil, Agusan , Rawa Tripa, Ulu Masen, Jantho Nature Reserve, and others), as well as Batang Toru and Pakpak Bharat [5]. In the last few decades, the decline in the orangutan population is estimated at 30-50% [6], even more than 80% when compared to the orangutan population in the last 75 years [7]. Overcoming the decline in the orangutan population, it is necessary to develop an orangutan conservation strategy to preserve and protect orangutans from extinction. The best long-term conservation strategy to maintain the orangutan population is the protection of natural populations and natural communities in the orangutan's natural habitat, known as in-situ conservation. However, the high level of human activity against forest destruction and encroachment of wild nature which directly threatens the existence of orangutans in their natural habitat has hampered in-situ conservation efforts [8]. One of the other efforts to prevent the extinction of endangered species is by maintaining natural individuals in controlled conditions and under human supervision, known as ex-situ conservation. Ex-situ conservation institutions in the North Sumatra area include the Siantar Zoo. Siantar Zoo has many types of endemic animals that make the animal park an area for public education on key species that are closely related to the balance of ecosystems in nature.
One of them is the Sumatran orangutan, which is an endemic animal that is a key species in its natural habitat.Siantar Zoo has 1 (one) juvenile male orangutan, aged ± 9 years, named Steve, and has been at the Siantar Zoo since 2012. Steve was initially placed in a cage until 2017, then the zoo Siantar animals have changed the shape of the cage to be semi-open (enclosure) until now, this situation will affect the behavior of individual orangutans [9]. [8] stated that differences in cage conditions can have a bad or good impact on the behavior and life of orangutans. Lack or poor quality of food sources, facilities and areas that are not large enough to support the survival given to orangutans will cause stress, obesity, and even death for orangutans. Furthermore, it was explained that changes in behavior that occur outside of nature due to environmental factors can also cause orangutans to lose their natural nature, especially for male orangutans who are more solitary than females. Therefore, it is necessary to conduct research on the behavior of individual male orangutans with a management system at the Siantar Zoo as an effort to preserve the Sumatran orangutan. Information regarding the behavior of the individual male orangutan (Steve) at the Siantar Zoo is still limited

METHODS
The study was conducted in August 2020 for 14 days, with a period of 6 hours (10.00 to 16.00 WIB) per day at the Siantar Zoo, North Sumatra Province. The object of this research is a male Sumatran orangutan named Steve who is ± 9 years old. Steve has a height of ± 135 cm and a weight of ± 58 Kg. This research was conducted using the Focal Animal Sampling method, namely in a certain period or time using one individual as the object of research, his behavior was observed. Observations were made within 2.5 m of the Sumatran orangutan enclosure.
Recording of orangutan behavior data using the Instantaneuous method, namely recording the behavior seen in orangutans at certain times and periods using a tally sheet table. Observation b. Bipedal (Bi), which is moving from place to place using both locomotion (legs) c. Climb (C), which is done by holding the object (tree trunk) with the four tools of motion and then moving in a vertical direction. d. Brachiation/swinging (Br), which is changing places using the second or fourth locomotion tools alternately through a swing rope.  The data on the behavior of the individual orangutans as the object of observation were then tabulated and the presentation determined using the formula used in the previous study by [10], as follows = (1)

General Behavior of Male Orangutans at Pematangsiantar Zoo
The results of the research that has been carried out on the individual behavior of male orangutans (Steve) are grouped into seven behavioral categories which show different percentages of frequency in each behavior category. The percentage of the frequency of Steve's individual behavior in general at the Zoo can be seen in the following : The movement behavior carried out by male orangutan Steve at the Siantar Zoo, such as moving from one place to another by walking on the ground, swinging to pick up food on the floor around the cage and climbing was obtained by 33.43%. This shows that the male orangutan Steve at the Siantar Zoo at the time of this study was seen to be more active in moving behavior. This situation is also influenced by the factor of providing enrichment in the form of a replica of the model tree and also the age and sex factor of Steve's orangutan who has entered adolescence. Ginting (2006) explains that the high percentage of moving of orangutans in ex-situ conservation areas shows that these orangutans have shown their natural nature, especially for foraging.

Movement Behavior
Movement behavior which includes 4 (four) sub-categories consisting of Quadrupedral, Bipedal, Climb, and Brachiation, the highest was obtained, including the Quadrupedral subcategory, and followed by the Brachiation, Climb, and Bipedal subcategories as shown in Figure 2. below. In Figure 2, it can be seen that the percentage of movement categories carried out by male orangutan Steve from the highest to the lowest in a row, namely quadrupedral behavior or walking using all four locomotion tools (hands and feet) is 49.61%.

Figure 3. Movement behavior with quadrupedral
Quadrupedral behavior or walking using four locomotion is the highest frequency of behavior category performed, it means that of the four ways of moving that Steve most often does is how to walk using his four locomotion tools (Figure 3). This is in accordance with the statement of [12] that Sumatran orangutans in zoos more often carry out locomotion activities or move places by walking on the ground. In addition to walking, the Sumatran orangutan also moves by means of brachiation or swinging by 19%, climbing or climbing by 15.91%) and bipedal by 15.59%.

Resting Behavior
Resting behavior which includes 4 (four) subcategories consisting of sitting, standing, lying down and sleeping, was found to be the highest among the sitting subcategories, and followed by standing, lying and sleeping subcategories as shown in  In Figure 4. it can be seen that the percentage of male orangutan resting behavior subcategories from the highest to the lowest, respectively, is sitting behavior (71.92%), followed by standing behavior (14.45%), lying behavior (12.26%). ), and sleep behavior 1.36%

Figure 5. (a) Lying rest behavior (b) Sitting rest behavior
Rest behavior is an inactive individual state which includes sitting, sleeping or lying down [13].
According to [14], the resting position of the orangutan is also influenced by the age of the orangutan. The male orangutan Steve, who is classified as a teenager, mostly engages in resting behavior by sitting, lying down, and occasionally hanging. According to [8] juvenile male orangutans spend their rest time sitting, hanging and lying down. This situation shows the high percentage of sitting done by male orangutans Steve. This is because sitting activity is a condition for orangutans to take a temporary break during the day. According to [12], an orangutan's temporary rest activity is a state of orangutans who are silent in one place between other activities, both sitting and lying positions which can be affected by temperature and weather.

Eating Behavior
Feeding behavior includes 3 subcategories consisting of the behavior of choosing feed, taking feed, and processing feed which is the highest obtained among them, subcategories of taking feed, processing feed and choosing feed. Figure 6. Diagram of the percentage of feeding behavior in male orangutans at the Siantar Zoo.
From Figure 6. it can be seen that the percentage of feeding behavior subcategories in male orangutans that are often carried out is the behavior of taking 40.79% followed by feeding behavior of 34.71%, and feeding behavior of 24.50%. the highest frequency of eating behavior subcategory, it means that of the three ways of eating behavior Steve is most often done by taking feed.

Figure 7. Orangutan (steve) selects and takes available feed
According to [12] taking food is part of the eating behavior of orangutans to get food that falls to the ground or a flat stucco area accompanied by moving behavior. After that, the male orangutan Steve will process the feed such as peeling and cleaning the feed and then chewing and swallowing the feed.

3.5.Playing Behavior
Play behavior includes the movement of orangutans playing alone by moving their bodies and playing with objects without any interaction with other individuals. The percentage of behavior in this playing subcategory can be seen in Figure 8. From Figure 8. it can be seen that the percentage of play behavior in Steve is more dominated by the behavior of moving his own body by 79% while playing behavior using objects is 21%.
According to [15], orangutan play behavior is categorized as playing alone and playin socially, playing alone is usually done around moving the body and playing with objects around. During the observation, it was recorded that the male orangutan Steve occasionally moved while rolling on the ground. This rolling behavior was included in the subcategory of body-moving play which was carried out when Steve's male orangutan picked up food on the floor. Apart from rolling, Steve's male orangutan also played with objects. The behavior of playing using objects includes using plastic and used bottles as a means of playing with Steve's male orangutan, such as putting his hand in plastic. This situation is because the demonstration cage is being thrown at by irresponsible visitors.
According to [12], juvenile orangutans at the Kasam Kulim zoo often use waste such as plastic food and drink bottles as a means of playing. It was recorded that once in a while, Steve's orangutan was seen drinking water in the pond using an old plastic bottle and then taking him to an artificial tree and playing with the object.

Agonistic Behavior
Agonistic behavior includes 3 (three) subcategories consisting of spitting, kissing squeaking and fighting visitors, the highest is spitting, followed by kissing squeaking and fighting visitors, as shown in Figure 10 below.  Figure 10, it can be seen that the percentage of agonistic behavior in male orangutans from highest to lowest, namely spitting behavior of 45.39%, kissing behavior or making sounds like kissing 27.96% and behavior against visitors 26.64%. According to [9], Spitting behavior is the behavior of issuing liquid from the mouth to targets such as keeper or visitors. During the observation, it was recorded that the male orangutan, Steve, often spat at visitors. According to [12], the spitting behavior of orangutans is a sign or code to get food and as a form of communication or introduction to new visitors and keepers.

Self-care behavior
Self-care behavior is the second lowest behavior (figure 4.1) of the seven individual behavior categories of Steve's male orangutan. Self-care behavior includes licking or licking and Scratching body/Grooming or scratching which is the highest, including licking and followed by subcategories which can be seen in Figure 11. From Figure 11. it can be seen that the percentage of self-care behavior in male orangutans is more dominated by scratching body/grooming behavior, which is 78.26% when compared to body licking behavior which is only 21.74%. According to Purnawan et al., (2016) orangutans generally scratch their bodies (grooming) themselves at rest or after defecating during the day and in the evening when they want to sleep. Grooming behavior is one of the activities that is often carried out with the aim of cleaning oneself from dirt or parasites attached to the orangutan's body. Steve is seen doing grooming behavior on the back and hands in between his resting behavior ( Figure 12) According to [14], grooming behavior is mostly carried out on the hands and feet of orangutans.
Meanwhile, lick behavior is mostly carried out on injured body parts. According to [9], the behavior of licking body parts with the tongue is one of the efforts to accelerate wound healing because of the saliva content and also to clean orangutans. Licking behavior is a behavior that results from learning from a certain condition that allows the orangutan instinct to take care of itself. Meanwhile, under observation, male orangutan Steve performed a licking behavior to clean himself and did not appear to be injured at all.

Disposal Behavior
The behavior of defecating is the behavior with the lowest percentage of the seven categories of individual behavior. The percentage of defecation behavior includes defecation and urination which can be seen in Figure 13. From Figure 13. it can be seen that the percentage of the subcategory of defecation behavior in male orangutans is dominated by urination or urination behavior by 64.29% while defecation or defecation behavior is 35.71%. Steve's male orangutans urinate and defecate regularly every day, usually Steve's male orangutans defecate a few minutes after leaving the holding cage, while Steve's male orangutan urination is usually done by sitting or standing on the display tree in the morning before noon ( Figure 14). According to [17], when orangutans come out of their nests in their natural habitat, orangutans have a habit of throwing feces when they are about to start their daily behavior. The way orangutans defecate is usually while hanging with both hands holding branches. This situation is in accordance with [9] 's opinion that orangutans defecate and urinate by squatting on a stick with both hands hanging on a stick.

Conclusion
From the results of this study, it can be concluded that the percentage of individual behavior frequencies of male orangutans in general at THPS, namely moving behavior is 33.43%, resting behavior is 27.36%, eating behavior is 25.24%, playing behavior is 9%, agonistic behavio r is 3.64. %, 0.83% self-care behavior and 0.5% littering behavior.