Alarm reactions of red deer (Cervus elaphus) in the Paneveggio-Pale di San Martino regional Park

Increasingly, both accessible and remote areas are being used for recreational activities. The amplified anthropogenic impact is believed to be a significant factor in the disturbance of wildlife [1]. In the Red deer (Cervus elaphus), the heightened exposure to anthropogenic disturbance from human recreation is linked to the expression of behaviors assimilable to predation perception [2]. A population of red deer is kept in Paneveggio Pale di San Martino Natural Park (Trento-IT) for didactic purposes; the population is composed of a maximum of 20 animals and lives in a wide area, with lawns and forest. The animals are subject to intense human exposure throughout the year with elevated incidences in the summer months. Our study was aimed to develop a pasture management plan to avoid conflict between the risk of high stress levels for the animals and educational and recreative use of the area, considering the need to improve the botanical richness inside the shelter. For one week, during summer, 18 subjects were observed: 3 adult males, 10 adult females and 5 calves. The animals tended to separate in a nursery group (females and calves) and a male predominant group (all adult males and 1/2 old females). Different alarm reactions were examined in order to determine how the apparent stress level of the animals change through the course of the day and in response to different stimuli. Three types of visual stimuli were performed: a person standing, a person moving and an umbrella suddenly opened. The acoustic stimuli were two: a low tone sound produced by the observers and a grass rustling sound [3]. Three behavioural states were recorded during the observations: vigilant lying, vigilant standing and vigilant moving [2]. A growing response intensity was associated with changing the state from a vigilant lying to vigilant standing position and from vigilant standing to vigilant moving. Behavioural responses and their intensity in response to visual and acoustic stimuli were observed during different times of the day (morning and afternoon; period of 30-60min) as well as before, during, and after tourists’ presence. The reactions to these disturbances were liveobserved both inside and outside the shelter by three observers; in addition, many photos and video were recorded. The stronger disturbance response was recorded in the deer during and immediately after the days of major tourist affluence, and when performing the visual stimuli inside the shelter. Deer displayed higher alert behaviours during and after weekends, with a peak of response intensity on Sunday afternoons and Monday mornings. Moreover, the visual stimuli were associated with greater responses, while acoustic stimuli caused nearly no response. Another major difference was noticeable between groups. The nursery group showed a higher number of alarm signals and a higher response intensity and tended to stay far and well hidden from the tourists. It is therefore crucial to pay severe attention during reproductive and lactation periods and plan needed pasture management measures during less disturbed days and months.