Wild boars disturb hair-tube sampling, but adequate replication and inclusion of disturbed tubes retain sampling integrity

Abstract

Structure and composition of small mammal assemblages are excellent indicators of habitat quality and often used to study impacts of perturbations such as wildfires on faunal communities. One of the most efficient and widely used tools for assessing small mammalian assemblages are hair-tubes. Despite their efficiency, they are often damaged by non-target species such as wild boar (Sus scrofa). However, the impact of such damage on the use of hair-tubes has apparently never been formally assessed. In this study, wildlife-induced disturbance of hair-tube sampling was quantified in the mountain chain of Monte Pisano (Italy), a fire-prone area. At each site, two hair-tubes were tied together to form a “pan-pipe” and placed in three repetitions. Disturbances were measured, including camera-traps to identify damaging species. Although approximately 27% (N=164/600) of pan-pipes were disturbed, two pan-pipes per site resulted in 96.5% undisturbed pan-pipes. Unexpectedly, as the most frequently disturbed pan-pipes were those monitored by camera-traps, our rates were considered overestimates. Perhaps this was due to attraction of the wild boars, by means of olfactory/acoustic signals. Boar was the wild species with the greatest impact on pan-pipes, and its impact and rates of all wildlife disturbances did not differ among habitats. Furthermore, displaced tubes were not significantly different from undisturbed tubes in terms of numbers of hairs collected and biodiversity estimates. To avoid data loss when conducting pan-pipe monitoring, we suggest using at least two pan-pipes per site. Finally, displaced tubes that are retrieved should provide reliable data.