We all love the experience of sitting at a waterhole, watching the animals come for a drink, interact with each other, rest, and saunter away. But we must ask ourselves, how is our presence affecting them? Tourism has many benefits to people, economies, and wildlife, but we need to fully understand how our encroachment into wild areas may be resulting in changes to animal behaviour, resource acquisition, and ecosystems.
Jessy Patterson’s (University of Georgia) first (PhD) dissertation chapter focussed on providing a better understanding of the effects of human presence on mammal waterhole attendance and diel (daily) activity patterns. This work, conducted in collaboration with the University of Georgia’s Savannah River Ecology Lab and the Ongava Research Centre, has just been published in Journal of Zoology. Below, Jessy guides us through the study and some of its most interesting results.
Several studies have shown that tourism activities can negatively impact wildlife, inducing fear and aggression responses when tourists are nearby. We also know that animals can become habituated to human presence, which enhances our viewing experience, but may also result in negative consequences for the animals. Additionally, humans are often present at waterholes for population monitoring purposes, namely conducting wildlife game counts for several days at a time. If humans are counting animals, and animals are avoiding the areas because they fear humans, the resulting population estimates may be skewed. As such, it is important for us to determine how human presence may be affecting mammal attendance at waterholes. Monitoring of wildlife behavioural changes in response to human activity is crucial to further develop wildlife tourism opportunities in a way that optimises the impact of conservation goals.
This study was conducted on Ongava Game Reserve using 12 waterholes, five with human infrastructure (buildings and human presence) and seven that are more remote with very little to no human presence except for infrequent passing by of safari or staff vehicles (Figure 1).
Every year during the height of the dry season (September-October), Ongava staff conduct wildlife counts where teams of two or three observers are posted at every waterhole for a 72-hour period during the full moon period when visibility of wildlife is clearest. During the 2016 and 2022 annual waterhole counts, motion-activated camera traps were also deployed at the waterholes from 72h before to 72h after the observer counts, capturing periods of time before, during, and after humans were present at the waterhole.
Using the data extracted from images from these cameras, we run various statistical analyses to determine if the number of waterhole visits, time spent at the waterhole, and diel activity patterns differed based on period (before/during/after the annual counts), waterhole type (remote/lodge), and time of day (day/night) for all carnivore and herbivore species with a body mass above ~2kg.
Our results revealed no differences in the number of visits based on human presence for any of the 17 mammal species studied. However, giraffes spent more time at waterholes before observer presence compared to during. We also found no differences in diel activity patterns between periods based on waterhole type for any species. However, several species changed their activity patterns when human observers were present (Figure 3). Most notably, we found that four nocturnal/crepuscular carnivore species (spotted hyena, brown hyena, black-backed jackal, and lion) became more active during daytime hours during the counts when humans never left the waterholes compared to before and after the counts.
It is uncommon on Ongava for humans to be at waterholes during nighttime hours when these species are most active; therefore, the presence of humans during counts at night may have caused these carnivore species to adjust their activity patterns to daytime hours when they are more accustomed to humans. Additionally, the carnivores may have waited throughout the night for humans to leave the waterhole and when they did not, the carnivores had to drink during the day instead. Due to this change in temporal activity, it is likely four ungulate species (common duiker, springbok, mountain zebra, and plains zebra) shifted their activity during human presence to avoid these predator species due to a heightened perceived predation risk of natural predators.
Further investigation showed that while humans were absent, 75% of the carnivore-ungulate pairs had different activity patterns with little overlap, where carnivores were primarily crepuscular, and ungulates were primarily diurnal. However, while humans were present, only 44% of the pairs had differing activity patterns (Figure 3) as the carnivores became more diurnal. These modifications of mammal temporal activity patterns due to human presence could eventually lead to changes in community structure and trophic dynamics because of altered predator-prey interactions. Therefore, it is important to consider these behavioural changes that occur in response to human presence, and how they could impact the landscape of fear and perceived risk for mammal species.
