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Methods

To observe the social hierarchy of C. petaurista a group consisting of two females and one male was monitored in an enclosure at the Central Florida Zoo. The dominant male, named Timbi, was born in 2003. The eldest female, Mama (depicted in Figure 1.2 below), was born in 1999. The younger female, Tumani, was born in 2001. Both Mama and Timbi had a section of their tail removed for health reasons. There are a few notable relationships within this group. Timbi and Mama were a former mating pair, while Timbi and Tumani are half siblings on their father's side.

Figure 1.2: Social Grooming observed in C. Petaurista.

It is important to note that this study is a direct continuation of another study conducted on the same subjects by UCF student researcher Ryan Domitz. In his study, he observed hierarchy in terms of grooming solicitation and determined how the subjects spent their time on average. During his observations, Domitz observed a change within the social hierarchy. On March 26th, 2017, there was an aggression incident between Tumani and Mama within the enclosure den. Mama had to be removed from the exhibit after losing the confrontation with Tumani and needing medical care. When Mama was reintroduced back into the enclosure, Tumani had taken her place on the social hierarchy leaving Mama with the lowest social status of the three subjects. This change in social status led to an increase in agonistic behavior from Timbi and Tumani directed at Mama. This shift persisted throughout the remainder of this student's study with no signs of a reversal back to the status quo before the aggression incident leaving the hierarchy as Timbi > Tumani > Mama when this study commenced.

The enclosure at the Central Florida Zoo is a fenced in box shaped area with dimensions of 9.144 x 7.62 x 3.353 meters. Three of the walls are held up by cement blocks with the front and most of the roof of the enclosure are fenced in. There is also a fenced in window built into the center of the back wall. On the left wall of the enclosure, there are two enclosure doors leading into a neighboring den where the Guenons are moved when the enclosure is cleaned or overnight when the zoo is closed. The guenons are also moved into the den when the outside temperature reaches below 4.44°C. Within the confines of the enclosure walls, there are several tree-like structures with branches that stretch across the enclosure above the ground. The back half of the enclosure is covered with a closed roof and features a small treehouse for the guenons to retreat to for privacy. Enrichment is occasionally placed around the enclosure before the three individuals are released from the den in the morning or after enclosure cleaning. This enrichment varied from new foods like full branches and nuts to additional rope structures and ladders placed in various locations around the enclosure. Outside the enclosure, there is a Brown Lemur (Eulemur fulvus) exhibit to the left, a Red Ruffed Lemur (Varecia rubra) exhibit to the right, and a RingTailed Lemur (Lemur catta) exhibit directly across from the Guenon enclosure. The Brown Lemur and Ring Tailed Lemur were relatively quiet and rarely produced vocalizations that produced a reaction from the guenons. The Red Ruffed Lemur, however, produced loud snarling and squeaking vocalizations at varying times each day that sometimes produced a response from the guenons. Inside the enclosure, the guenons had direct contact with Eastern Grey Squirrels (Sciurus carolinensis) and House Sparrows (Passer domesticus) as these animals were small enough to slip through the bars and enter the enclosure. This was commonplace since these animals were attracted to the primate biscuits scattered throughout the exhibit.

To observe the social hierarchy among these three individuals, behavioral observations were made over 2 to 4 hour periods at random time intervals, three times a week for a total of 60.5 hours (between May 22, 2017 and August 28, 2017). Observations took place at the front of the enclosure in full view of the animals. Zoo guests were also present during observations with varying degrees of crowd size and noise levels. It is also notable that the guenons were sent into the den around noon for enclosure cleaning and feeding which may have modified behavior. A template was used to record notes during observation sessions. A new template sheet was used for each 15-minute period during observations. A 6x6 grid was on the top of each sheet to take down the locations of each specimen at the beginning of each 15-minute time block. The locations of enrichment and disputed territory were also marked down on the grid. Below the grid, behavioral observations were recorded. In a column next to the observations, notes on agonistic fights were recorded keeping track of which individual won the encounter. "Winning" an encounter was defined by either successfully taking territory, food, or another resource or receiving a submissive gesture or facial expression from another individual. The submissive gestures recorded in these cases were either a presenting gesture or the baring of teeth in response to aggression. Social grooming was also recorded, taking note who received the grooming and the length of the grooming if it lasted more than 1 minute. This data was analyzed by counting the number of times each specimen achieved victory in agonistic encounters. The number of grooming incidents was also counted, taking note of the direction of each grooming observed and the average length of grooming time between each possible pair.

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