Positions and movement of the tail in wild boar Sus scrofa

Abstract

The wild boar Sus scrofa is widely distributed, extending from Europe into Minor, Central, and South-eastern Asia. Despite that, the biology of this species is well known, little is known about the significance of its tail position and movement. In this connection, we studied the link between tail position and movement and the corresponding behaviour as well as whether they are affected by environmental factors. The fieldwork was carried out in the spring-summer period of 2017–2018 by camera traps on the territory of two Bulgarian state hunting grounds. The total number of trap nights was 1558 and the registered videos of wild boars were 220. In the videos, 112 females, 42 males, 141 juveniles (1–2 years old) and 198 offspring were identified. Five tail positions were defined: hanging, wagging, horizontal, raised, and arched. By applying the Generalized Linear Model, it was found that Behaviour, Sex and Habitat significantly influence the tail position. The observed behaviours were divided into two main categories - active and passive. The hanging and wagging tail prevailed over the other tail positions with the tail usually hung during foraging and digging. The wagging prevailed in exploratory and amicable behaviour, and the tails were dominantly raised in cases of agonistic behaviour. During the passive behaviours, the hanging tail also prevailed. Given that wild boar is an important species for both biodiversity and hunting practices in many countries, the research done allows us to conclude that systematic camera trapping is a powerful tool for studying its behaviour, which could contribute to the management of the species.