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

Introduction

Conditions in captivity typically vary greatly from conditions in the wild. As a consequence, behaviors observed in captive animals may diverge considerably from those of wild animals (Maple, 2007). In the wild, male giraffes only loosely associate with one another and become increasingly solitary as they grow older (Bercovitch et al., 2006; Dagg and Foster, 1976). Bulls adopt a roaming male tactic, traveling and evaluating females they encounter for sexual receptivity, as females are in estrous one day of about every two weeks and are frequently in gestation (Bercovitch et al., 2006).

To date, little research has been conducted on groups of all-male captive giraffes, since such grouping is a more recent trend in zoos affiliated with the American Zoological Association, which manages the giraffe populations of all zoos to ensure their survival through control of reproduction. Male giraffes are increasingly placed in long-term single-sex herds in captivity, whereas similar all-male herds are short-lasting in the wild (Bercovitch and Berry, 2015). As a result, it is possible to observe the appearance of less common behaviors occurring in herds of captive males. Due to the low degree of association between males in the wild, different social behaviors may only occur at low frequency in that setting. If social interactions are not altered by captive conditions, frequency would be increased only due to the proximity inherent to captive conditions and the resulting greater potential for interactions, allowing the observation of otherwise rare behaviors without lengthy field studies (Bashaw, 2004). Alternatively, these behaviors may be due to the conditions imposed by captivity.

This study aims to examine giraffe social behaviors present in an all-male population at the Central Florida Zoo and Botanical Gardens. This population is comprised of one adult and two subadult giraffes, all of varying species. Because all-male groups are short-lasting in the wild and because these species do not occupy ranges that typically overlap in the wild, behaviors that occur at low frequencies in the wild, which are typically missed in observational studies, may be more clearly observed in captivity. It is also possible that some of the behaviors seen may be due to the unique circumstance of these three giraffes (being held in close quarters for prolonged periods of time).

Specifically, we hypothesize that there will be a clear dominance hierarchy: the eldest giraffe is most likely the most dominant member of the group, and the two subadult giraffes are either equal within the hierarchy, due to their similar age, or there would be a clear pattern of behaviors to indicate which one is dominant to the other. Based on this prediction, we further hypothesize that the eldest would perform most, if not all, dominance and sociosexual behaviors. Furthermore, due to the short-lasting nature of wild all-male groups, we predict that there would be a lack of apparent social preferences through random affiliative behaviors. Specifically, we predict that the two subadult giraffes would avoid the most dominant giraffe and we further predict that hitting between the eldest and the others would appear more aggressive, while hitting between the two subadults would be gentler and a form of sparring.

Materials and Methods >>