Adolescence and the development of social behaviour in giraffes

Abstract

All mammals experience different life stages as they develop, each of which is characterised by particular physical and behavioural changes. Despite the emergence of sophisticated behaviour analysis techniques, the ways in which social behaviour varies by life stage, and how this is influenced by an individual’s sex, is relatively understudied in most social mammals other than primates and elephants. Understanding the social requirements of mammals should be a central and critical component to their conservation, captive management and welfare. Here, we apply social network analysis techniques to understand how social behaviour differs with life stage in the giraffe, a gregarious fission–fusion mammal. We studied two wild populations of giraffes in Kenya and found that adolescents have significantly stronger associations with adolescents of their own sex first and foremost, then adults of their own sex. Other associations were significantly lower than would be expected, or non-significant. Our results suggest that adolescence in both male and female giraffes shares similar features to adolescence in other social mammal species. We discuss how the application of such knowledge might improve the management and welfare of captive giraffes.

Using spot pattern recognition to examine population biology, evolutionary ecology, sociality, and movements of giraffes: a 70-year retrospective

“…Carter et al (2013a, b) showed preferred and avoided relationships among females, but not among males, in a large population of Angolan giraffes; females in 'preferred' relationships were more related to each other than expected from random associations; female (but not male) relationships were stable over time; and young females (compared with older females) increased their number of associations as they aged. Studies of reticulated (VanderWaal et al 2014), Masai (Lavista Ferres et al 2021, and Rothschild's giraffes (Muller et al 2022) also confirmed association patterns were influenced by age and sex class. Other studies examined how giraffe social affiliations were influenced by activity (Muller et al 2018b), humans (Bond et al 2021c), humans and lions (Muller et al 2019), season (Prehn et al 2019), a male's color (Castles et al 2019), and presence of calves in female groups (Saito et al 2020), as well as how associations influence male rutting (Seeber et al 2013), grouping (Bercovitch and Berry 2014), and sparring behaviors (Granweiler et al 2021).…”

Seasonal variation in giraffe population density and abundance in the Tsavo landscape, Kenya

“…Sex and age class identification were determined using external genitalia, body size, pelage and presence or absence of mammary glands (D'haen et al, 2019). Following Muller et al (2022), adults were individuals aged 4+ years, subadults were 12 months or more but <4 years and juveniles were <12 months.…”

Identifying Essential Elements of Good Giraffe Welfare—Can We Use Knowledge of a Species’ Fundamental Needs to Develop Welfare-Focussed Husbandry?

“…Examples of how this seven-step W-E-L-F-A-R-E checklist could form the basis for a validated systematic and repeatable assessment of giraffe emotional states are provided in Table 2. Changes in underlying physiological state, e.g., reproduction [48,76,77] and senescence [78], will influence giraffe activity and, therefore, behavioural expression and body language; as such individual animal physiology and development, plus season, need to be considered when making positive inferences of mental states in the zoo. Suggestions for what mental welfare outputs may present as are also given to encourage others to consider the feasibility of their measurement.…”