Responses of small vertebrates to linear clearings in a South Australian woodland

Abstract

<jats:title>Abstract</jats:title><jats:p>This work assesses whether the width and “permanence” of linear clearings affects the distribution and movement patterns of small, terrestrial vertebrates in a native South Australian woodland. We examined the influence of narrow (1.5 and 4.2 m), non‐permanent seismic exploration tracks; and wide (6–7 and 12–15 m), permanent fire tracks. There were 1,007 captures of 14 species (four amphibians, six reptiles, four mammals) from 18,000 trap days/nights across 15 sites. Total species richness was highest adjacent to 6–7 m wide permanent tracks (8.3) and lowest in areas without clearings (5.3). There was heterogeneity of captures between track types (<jats:italic>p</jats:italic> &lt; 0.008), species (<jats:italic>p</jats:italic> &lt; 0.001), and species by track type (<jats:italic>p</jats:italic> &lt; 0.001). <jats:italic>Antechinus flavipes</jats:italic> was most abundant adjacent to both types of permanent tracks, probably as a result of increased habitat complexity at these sites. Twenty‐four percent of movements by recaptured <jats:italic>A. flavipes</jats:italic> involved track crossings. Animals crossed all track types; nevertheless, individuals were more likely to be recaptured on the same side of a track. Individuals were less likely to cross permanent tracks (<jats:italic>p</jats:italic> = 0.025 for 6–7 m and <jats:italic>p</jats:italic> = 0.008 for 12 to 15‐m‐wide tracks), with females being particularly inhibited. Although 11 % of 56 recaptured <jats:italic>Rattus</jats:italic> spp. had crossed a track, no individuals crossed the 12 to 15‐m permanent tracks. In the habitat type studied here, narrow seismic lines may have a slightly positive effect on some ground‐dwelling vertebrates, and do not appear to substantially inhibit movement. However, there is a need to carefully manage permanent tracks, which could isolate faunal populations.</jats:p>