We investigated densities of four common species, Wrentit (Chamaea fasciata), Spotted Towhee (Piplio erythrophthalmus), Bewick's Wren (Thryomanes bewickii), and Orange-crowned Warbler (Vermivora celata) in relation to trail width in chaparral habitats of Mt. Tamalpais, Marin County, California. Point count sampling stations were assigned to one of three trail width groups—thin (î 2 m), medium
... [Show full abstract] (2.1-4 m), and wide (>4 m). We found a marginally significant (P < 0.1) negative effect of trail width on the density of Spotted Towhee when thin trails were compared to medium/wide trails. For the other three species our results suggest a trail width effect when thin trails were compared to medium/wide trails (P < 0.2), although additional study is needed to confirm or negate these tentative conclusions. Only one species, Orange-crowned Warbler, showed a positive relationship between density and trail width