Publication Type: | Journal Article |
Year of Publication: | 1995 |
Authors: | Brown, WM, Drewien, RC |
Journal: | Wildlife Society Bulletin |
Volume: | 23 |
Issue: | 2 |
Date Published: | 1995 |
ISBN Number: | 00917648 |
Keywords: | Gruidae, Grus, Grus americana, Grus canadensis, Grus grus |
Abstract: | Collisions with power lines are a source of mortality to cranes (Grus americana and Grus canadensis), waterfowl, and other birds. We evaluated 2 power line markers for reducing crane and waterfowl mortality in the San Luis Valley, Colorado and examined factors contributing to collisions and marker effectiveness. Collision mortality rates at 8 segments (about 0.8 km each) of power lines marked with either yellow spiral vibration dampers or yellow fiberglass swinging plates were compared with 8 adjoining unmarked segments. During 3 spring and 3 fall migration periods (1988-1991), estimated mortality on study segments was 706, including ≥35 species. Waterfowl and cranes constituted >80% of mortality. Both market types reduced mortality (P < 0.005). Birds reacted to marked lines at greater distances and increased their altitude as compared to unmarked lines (P < 0.0001). Factors affecting collisions or marker effectiveness included wind (P = 0.008), nocturnal flights and disturbance (P < 0.005), and age of sandhill cranes (P < 0.001). Neither marker performed better in all study seasons; each may have had unique benefits. Plates damaged distribution lines, precluding their continued use; however, a new marker from Europe which incorporates the benefits of both plates and dampers should be evaluated, as it may best protect against collision losses. |
URL: | http://www.jstor.org/stable/3782794 |
Short Title: | Wildlife Society Bulletin |
Taxonomic name: