Use of artificially created Douglas-fir snags by cavity-nesting birds

• Published in: Western journal of applied forestry Vol. 12; no. 3
• Main Authors: Chambers, C.L, Carrigan, T, Sabin, T.E, Tappeiner, J, McComb, W.C
• Format: Journal Article
• Language: English
• Published: 01.07.1997
• Subjects: ANIMAL SALVAJE; ANIMAL SAUVAGE; ARBOLES; ARBRE; BIRDS; CAVITIES IN TREES; DEAD TREES; HABITAT; HABITATS; OISEAU; OREGON; PAJAROS; PSEUDOTSUGA MENZIESII; REGIME SYLVICOLE; SILVICULTURAL SYSTEMS; SISTEMAS SILVICULTURALES; TREES; WILD ANIMALS
• ISSN: 0885-6095; 1938-3770
• DOI: 10.1093/wjaf/12.3.93

In western Oregon, we created snags by sawing tops off live Douglas-fir (Pseudotsuga menziesii) (n = 821) trees and monitored their condition and use by cavity-nesting birds. We created snags in three silvicultural treatments: modified clearcut stands, two-story stands, and small-patch group-selection stands. We used two snag patterns: clumped and scattered. Created snags averaged 3.8/ha in density, 17 m in height, and 75 cm in diameter. Chainsaw-topped snags were used by cavity nesters within 5 yr of creation. Abundance of excavated cavities increased in all silvicultural treatments (P = 0.0001) and was higher in two story and clearcut stands than in small-patch stands (P less than or equal to 0.0004). We did not, however, find that snag pattern (clumped v. scattered) affected use by cavity-nesting birds based on abundance of excavated cavities (P 0.6). We observed excavated cavities in five hardwood species indicating that hardwoods represented an important resource for cavity-nesting birds. Creating conifer snags by topping and retaining hardwoods may retain on increase populations of cavity nesters in areas with low natural snag density