干旱区生态环境知识资源中心

We studied rock climbing and bird communities associated with cliffs, with and without rock climbing, at joshua Tree National Park, California. Bird communities differed between sites with different levels of rock climbing. Four bird species were detected only at cliffs where no climbing occurred; 5 species were detected only at cliffs with moderate levels of climbing activity; and 3 species were seen only at cliffs with many popular climbing routes. European starlings (Sturnus vulgaris) and brown-headed cowbirds (Molothrus aler) were seen only at climbed cliffs. Birds at unclimbed cliffs were more likely to be perched at the faces of cliffs, whereas birds at popular climbing cliffs were more likely to be flying. At popular cliffs, birds were usually seen away from cliff faces, whereas at unclimbed cliffs birds were more likely to be detected near cliff faces.