Anthropogenic Influences on Distance Traveled and Vigilance Behavior and Stress-Related Endocrine Correlates in Free-Roaming Giraffes

Abstract

Giraffes are an important tourist attraction, and human presence to wildlife is increasing. This has an impact on an animal’s behavior and its endocrine correlates. Studies on other species show alterations in movement patterns, vigilance, and stress-related hormone levels in the presence of humans. Limited information is available on how anthropogenic activities alter giraffe’s behavior, social structure, and related endocrine parameters. The purpose of this study was to obtain insight into anthropogenic influences on giraffe’s behavior and adrenal activity. We used GPS devices mounted onto giraffes to compare the distance walked in the presence or absence of human observers. We also conducted behavioral observations to assess their vigilance and collected fecal samples to analyze their fecal glucocorticoid metabolite (fGCM) concentrations. Giraffes walked significantly further distances in the presence of humans, but the cumulative time that observers were present decreased the hourly distance walked with an observer present, suggesting that the giraffes were becoming habituated. The number of observers present significantly increased the percentage of time spent on observing an observer as well as the number of unhabituated individuals present in the herd. The percentage of time spent observing a human observer did not decrease with the increase of habituation. Last, fGCM concentrations increased with human presence but decreased when individuals became habituated to human presence. More research is needed to understand the effect of anthropogenic influences in different scenarios (e.g., tourism, vehicles, hunting, etc.).

Applying Behavioral and Physiological Measures to Assess the Relative Impact of the Prolonged COVID-19 Pandemic Closure on Two Mammal Species at the Oregon Zoo: Cheetah (A. jubatus) and Giraffe (G. c. reticulata and G. c. tippelskirchii)

“…Additionally, research conducted on various zebra exhibits found that alert (in some papers, alert and vigilance share the same definition) and locomotive behaviors tended to decrease as visitor numbers increased [ 56 ]. Interestingly, a recent study showed a positive correlation in the time the giraffes spent ‘observing the observer’ (author definition of vigilance behavior [ 57 ], page six) and number of observers present. However, this study had a maximum of three observers—drastically less than the typical visitor numbers experienced in a zoo setting—and the quantity of observers may not have reached the ‘white noise’ effect.…”

Vigilance behaviour during the calving season in female Tibetan antelopes (Pantholops hodgsonii)

“…Besides, female Tibetan antelopes remained close to their calves. In giraffes ( Giraffa camelopardalis ), females with young calves are more frequently found close to traditional homesteads (bomas) compared to females without young calves ( Scheijen et al 2021 ). In addition, while male impalas ( Aepyceros melampus ) show greater vigilance than females ( Olivier Pays et al 2012 ), females in other species show a higher level of group vigilance than males ( Michelena et al 2006 , Barnier et al 2016 ).…”

Biofluorescence and predator avoidance in the giraffe

“…The giraffe ( Giraffa camelopardalis ) is thought to have a high visual acuity, with relatively large eyes and excellent vision (Ishengoma et al, 2017), the capacity to solve spatial details (Veilleux & Kirk, 2014), and the ability to perceive movement to a distance of 2 km (Dagg & Foster, 1976). Giraffes are active mostly in the day (Burger et al, 2020; Scheijen et al, 2021; van der Jeugd & Prins, 2000), with group members sharing in vigilance at night while taking turns sleeping for short periods (Burger et al, 2020). Two of the giraffe's main predators include two members of the family Felidae, African lions ( Panthera leo ) and leopards ( Panthera pardus ) (Dagg & Foster, 1976).…”