University of Central Florida Undergraduate Research Journal - Social Behavior in a Herd of Captive Male Giraffes
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Social Behavior in a Herd of Captive Male Giraffes

By: Patrick Ziarnowski and Kaidi Fenrich | Mentor: Frank Logiudice

Materials and Methods

Central Florida Zoo houses one adult giraffe and two subadult male giraffes, all of known pedigree and of different species in the same genus: Emba, a twenty-year-old Rothschild’s giraffe (G. camelopardalis rothschildi); Rafiki, a four-year-old reticulated giraffe (G. reticulata); and Gage, a three-year-old Masai giraffe (G. tippelskirchi).1 Each giraffe can be readily distinguished by its pelage and ossicones.

During business hours (09:00–17:00), the giraffes are located in the outdoor exhibit (approximately 800 m2) replenished daily and given access to ad libitum ("at one's pleasure") alfalfa hay that is located in three feeders spread throughout the enclosure, while water is available from two different containers. Around 16:30, the giraffes are brought into the holding yard with access to their barn.

We conducted fieldwork from January 11, 2016 to April 15, 2016 (PZ) and from May 16, 2016 to July 26, 2016 (KF) at the Central Florida Zoo from public walkways during business hours. In total, we made 198.3 h of observations over 62 days and recorded social behaviors using a combination of all-occurrence and ad libitum sampling, by which the observer records all occurrences of the behaviors of interest, as well as the context in which they occur. Due to the nature of this study, affiliative gestures, courtship and mate guarding, sparring and hitting, dominance behaviors, and attempted mounting were specifically observed. Based on the dominance hierarchy, we expected to observe a certain distribution of the actors and recipients involved in these social behaviors.

To investigate the distribution of affiliative behavior, our study looked at social exams and social rubbing, as both behaviors can be clearly identified and recorded. Due to the limited size of the enclosure, it was difficult to determine with great certainty whether a giraffe was truly following another or if they were walking in the same direction. Co-browsing and co-feeding were also recorded, as they are also considered affiliative in nature and can be recorded with little ambiguity.

Due to the extensiveness of anogenital exams performed by one giraffe, the study chose to measure flehmen responses. The flehmen response, from the German word for "curl the upper lip," is a behavior where an animal curls its upper lip and inhales through the mouth, holding that position for several seconds. It is an easily recognizable and observable behavior. In giraffes, it is generally accepted that the examiner attempts to stimulate the usually female recipient to urinate, after which the examiner samples the urine and performs the flehmen response. Anogenital exams and flehmen responses are both sociosexual in nature and commonly occur between a male giraffe and female giraffe pair.

We also recorded and observed sparring matches, a form of play, and hitting, a form of agonistic behavior, since both relate to the dominance hierarchy. We expected that sparring would be limited to giraffes equal in the dominance hierarchy, while hitting would be performed by a dominant giraffe toward a giraffe lower in the dominance hierarchy. Similarly, mounting may also provide clues, as it is a sociosexual behavior that is typically also related to the dominance hierarchy, with only an adult giraffe mounting a subadult giraffe and not conversely.

An ethogram is included in the appendix defining the above behaviors.

1 Zoo giraffes reach sexual maturity by age 3 or 4, and they live approximately 20–25 years (Dagg, 1976).

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