Impact of Human Nuisance Disturbance on Vigilance and Group Size of a Social Ungulate

Abstract

In social ungulates, the proportion of time devoted to vigilance is a function of group size (known as the group size effect). We studied how varying levels of human disturbance influence this function in the mountain gazelle (Gazella gazella) along the southern coastal plain of Israel. Based on current theory, we predicted that changes in the slope of this function should be associated with changes in average group size. In heavily disturbed areas, individual vigilance levels increased in the bigger groups, causing the vigilance vs. group size curve to flatten, i.e., vigilance was high in all group sizes. Consequently, and in accordance with theory, we found a negative relationship between group size and human disturbance. Specifically, we found that in open areas with low disturbance levels, gazelles were in bigger groups than in open areas with high disturbance levels. In social species, the disruption of behavioral patterns by increased human presence can affect their social structure. Because social structure is a key component in the evolution and dynamics of social species, its disruption by human disturbance can have a considerable effect on population performance even if the disturbance does not directly impact survival and reproduction. Social disruption due to increased access to natural areas should be an important consideration in managing fragmented landscapes.

Animal Behavior in Conservation Biology

“…Therefore it is relatively easy to model animal behaviors and provide reliable predictions for conservation applications. Human activities are usually observed to modify animal behaviors 5,15 that will ultimately impact biodiversity. To make ease of investigation, behavioral indicators can be used as cues of anthropogenic disturbances.…”

“…4,9,14,15 Leading animal behaviorists should mention the ways in which animal behavior and conservation interact, 2 investigate the conservation impacts of people, 4,15 and identify novel behavioral threats to wild populations of animals.…”

“…9 Animal behavioral studies should change their focus on study from individuals to populations of organisms as conservation biology which has successfully emerged from population ecology, population genetics, and population sociobiology. 4,9,14,15 Leading animal behaviorists should mention the ways in which animal behavior and conservation interact, 2 investigate the conservation impacts of people, 4,15 and identify novel behavioral threats to wild populations of animals. 13 Animal behaviorists may also act to conserve biodiversity by applying their professional skills to conservation problems, or they may act on a personal level by supporting conservation groups and acting locally to preserve animal habitats.…”

Influence of live-capture on risk perceptions of habituated samango monkeys

“…Red deer (Cervus elephus) respond with 90 increased vigilance to both recreational park users and hunters, although overall vigilance levels 91 are higher in the hunting season (Jayakody et al 2008). Roe deer (Benhaiem et al 2008) and 92 mountain gazelle (Gazella gazelle) (Manor and Saltz 2003) become more vigilant when and 93 where they are hunted or exposed to "human nuisance behavior". Red deer (Cervus elaphus) 94 shift habitats, trading off feeding opportunities to avoid human hunters (Lone et al 2015) and 95…”

Effect of ecotourism on plant biodiversity in Chelmir zone of Tandoureh National Park, Khorasan Razavi Province, Iran

“…As a consequence, negative impacts have been quickly observed for wildlife species and habitats due to air and water pollution, vegetation removal for tourist facilities and infrastructures (refuges, camping sites, roads, etc. ), reductions in plant and animal fitness, habitat loss and degradation (Steidl and Anthony 2000;Kelly et al 2002;Manor and Saltz 2003;Amo et al 2006;Rossi et al 2006;Griffin et al 2007).…”