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

Activitybudget and foraging patterns ofNubian giraffe (Giraffa camelopardalis camelopardalis) in Lake Nakuru National Park, Kenya

The activity budget of giraffe in various African populations has been studied extensively, revealing that it is affected by body size, foraging patterns, and sex. Foraging patterns show an animal's feeding choices in its environment and are influenced by resource availability, competition, and predation risk. The ability of giraffe to survive and reproduce is significantly impacted by the variation in activity budget and foraging across different ecosystems. Our study focused on evaluating the seasonal activity budgets and foraging patterns of Nubian giraffe in Lake Nakuru National Park, Kenya. We used the scan sampling method to record the activity budget of giraffe which included foraging, movement, resting, and drinking water. We then evaluated if activities varied with the seasons. A total of 11,280 activities were documented, with 4560 (40.4%) occurring during the dry season and 6720 (59.6%) during the wet season. Foraging accounted for 53% of the time budget during the dry season, but increased to 57% during the wet season. There was a slight drop in records of movement (22%; n = 995 of 4560) and resting (25%; n = 1145 of 4560) from the dry season to the wet season (20%; n = 1375 out of 6720 and 22%; n = 1515 of 6720). During the dry season, females (53%) foraged longer than males (47%), whereas males (44%) had longer resting periods than females (56%). Giraffe frequently fed on Vachellia xanthophloea (67%; n = 4136 of 6215 foraging records), Maytenus senegalensis (19%), and Solanum incanum (9%) over both seasons. Overall, seasons had little impact on giraffe activity time budgets and foraging patterns in Lake Nakuru National Park. A better insight into the behavioural patterns of this subspecies will allow managers to enhance the protection and conservation of the species and its habitat. Heavy foraging on Vachellia by giraffe at LNNP has been associated with a population decline in number, so perhaps planting more of this species in LNNP could promote a rebound in numbers.

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

Tibetan antelopes (Pantholopshodgsonii) migrate great distances to specific delivery and calving areas. In the current study, we investigated calving site selection and vigilance behaviour during delivery and nursing in migratory female Tibetan antelopes at Zonag Lake. According to observations and analysis, the females were distributed south of Zonag Lake, where vegetation was abundant. We determined their dates of migration (crossing the Qinghai-Tibet Highway observation site), showing a shift of one month during the period from June in 2008 to May 2021. Results also showed that 81.4% of females expressed high vigilance behaviour during calving and nursing compared to those without calves (7.1%). From delivery until calf standing, females were highly vigilant and spent considerable time scanning, with 96% of females showing vigilance behaviour. Females with calves (average 9.94 ± 0.62 s) spent more time on vigilance behaviour than females without calves (average 6.25 ± 1.38 s). Females with newborns spent the greatest amount of time being vigilant (average 51.63 ± 4.24 s). These results not only identify basic Tibetan antelope calving behaviour, but also provide scientific analysis and evidence for further ethological research on female Tibetan antelopes.

When to Return to Normal? Temporal Dynamics of Vigilance in Four Situations

Vigilance is an important behaviour to monitor the environment from detecting predators to tracking conspecifics. However, little is known about how vigilance changes over time either without disturbance (vigilance decrement) or after a change occurred. The time course of vigilance can indicate how animals perceive a situation and the potential mechanism used to deal with it. I investigated the time course of vigilance in Gouldian Finches in four situations (familiar environment, two changed environments–novel object at a neutral location (exploration trial) or above the feeder (neophobia trial), novel environment). The frequency of head movements was assessed in four consecutive 15-min blocks in same sex pairs with a high frequency generally seen as indicative of high vigilance. Vigilance decreased over time in the familiar situation indicating vigilance decrement with a similar time course in the exploration trial. Vigilance was consistently high in the neophobia trial and only returned to normal in the last block. Finally, vigilance plummeted in the novel environment and did not return to normal within an hour. Results suggest that perceived threats affected vigilance and that information gathering reduced uncertainty allowing vigilance to return to normal levels but with different time courses depending on the situation.

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)

The effect of visitor presence on zoo animals has been explored in numerous studies over the past two decades. However, the opportunities for observations without visitors have been very limited at most institutions. In 2020, the Oregon Zoo was closed, in response to the global SARS-CoV-2 (COVID-19) pandemic, from 15 March 2020 to 12 July 2020, resulting in approximately four consecutive months without visitor presence. This study aimed to quantify potential behavioral and hormonal changes expressed during two transition periods in zoo visitor attendance: the initial time period before and after closure in March 2020 and time before and after reopening in July 2020. Fecal glucocorticoid metabolite (fGM) concentrations of resident giraffes (n = 2) and cheetahs (n = 2) were tracked using enzyme immunoassay (EIA) analyses. Average fGM concentrations during the two transition periods were compared using a two-way mixed ANOVA. Additionally, twice-weekly scan sampling was used to quantify behavioral observations across the transitions, which were analyzed as individual behavior proportions. Individual behavior proportions were compared across the Zoo's opening status and time of day using Kruskal-Wallis (H) tests. The results of our analyses showed the following outcomes: (1) significant increases in fGM concentrations for cheetahs and giraffes between the transition periods but not within them; (2) a significant increase in time spent 'not visible' in the cheetahs in the second transition period; and (3) increased vigilance behaviors in the giraffes immediately after the Zoo's closure. However, the changes observed in fGM concentrations may be more strongly correlated with concomitant social changes (giraffes) and some medical events (cheetahs) rather than with the Zoo's opening status. Nevertheless, this study was able to quantify differences in behavioral frequencies and fGM concentration in cheetahs and giraffes at the Oregon Zoo during the times of transition between visitor's presence and absence. The results indicate that, while there was a possible, but relatively minor impact of the presence and absence of visitors on some behaviors, the differences observed in fGM concentration may have been more affected by some of the concomitant social changes and medical events that happened during the same period than by the presence or absence of visitors.