Impact of tourism on Nubian Ibex (Capra nubiana) revealed through assessment of behavioral indicators

Abstract

Behavioral indicators can provide critical information to conservation managers. Here we apply behavioral indicators based on foraging theory to quantify the effect of tourists on the critically endangered Nubian ibex (Capra nubiana). Ibex are habituated to human presence in En Avdat National Park, Israel; nevertheless, they exhibit heightened wariness of humans especially during the kidding season or when far from escape terrain. We applied behavioral indicators through the measurement of givingup-densities (GUD, the amount of food that a forager leaves behind in a resource patch) and vigilance behavior to investigate the spatial and temporal variation in the patch use behavior of Nubian ibex under the influence of tourism. We hypothesized that Nubian ibex should treat the presence of tourists in a similar matter to the risk of predation. Our results show that the impact of tourism on ibex significantly varied both temporally and spatially in response to tourist activity. In regard to the temporal variation, ibex had higher GUDs on weekends when tourist activity was high than on weekdays. Furthermore, ibex GUDs were highest in the habitat most frequented by tourists, but only at times of high tourist activity. In a second experiment, the presence of tourists in close proximity always caused Nubian ibex to increase their GUDs in resource patches, even on a steep slope. The spatial position of the tourists up slope or down slope from the ibex affected both GUDs and vigilance behavior. The response was especially sharp when the tourists disturbed ibex from up slope, blocking escape lines. Even for this apparently well-habituated population of ibex, tourist presence significantly increased foraging costs as revealed by behavioral indicators. This study demonstrates how applying methods from behavioral ecology to conservation problems allows access to useful information that may be difficult to obtain using other approaches. Key wor ds: behavioral indicators, conser vation, foraging costs, giving-up-densities, spatial and temporal variations, tourist presence, vigilance behavior [Behav Ecol].