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Full-Text Articles in Life Sciences
Marking Power Lines To Reduce Avian Collision Mortality In The San Luis Valley, Colorado, Wendy M. Brown, Roderick C. Drewien
Marking Power Lines To Reduce Avian Collision Mortality In The San Luis Valley, Colorado, Wendy M. Brown, Roderick C. Drewien
Proceedings of the North American Crane Workshop
We examined the effectiveness of 2 marking devices designed to increase visibility of power lines and reduce avian collision mortality during spring and fall migration periods, 1988-91, in the San Luis Valley, Colorado. Eight O.8-km segments of power line were marked with either yellow spiral vibration dampers or yellow fiberglass swinging plates and compared with 8 adjoining unmarked segments. Primary species groups studied included cranes (Grus canadensis and G. americana), Canada geese (Branta canadensis), and ducks (various Anatinae). Raptors, shorebirds, wading birds, and passerines were also monitored. Both marker types reduced avian collision mortality by …
Contaminants In Habitat, Tissues, And Eggs Of Whooping Cranes, James C. Lewis, Roderick C. Drewien, Ernie Kuyt, Charles Sanchez Jr.
Contaminants In Habitat, Tissues, And Eggs Of Whooping Cranes, James C. Lewis, Roderick C. Drewien, Ernie Kuyt, Charles Sanchez Jr.
Proceedings of the North American Crane Workshop
Sampling of contaminants in the principal habitat areas of whooping cranes (Grus americana) of both the Rocky Mountain and the Aransas/Wood Buffalo National Park whooping crane populations began in the mid-1980's. Contaminants in eggs and tissues of whooping cranes were sampled opportunistically since the 1960's. Chlorinated hydrocarbons existed in low levels in the environment. Some trace elements including aluminum, arsenic, cadmium, chromium, copper. mercury, selenium, and zinc are of sufficient abundance to justify continued monitoring. Declines over time in residues of DDT and mercury in tissues and eggs reflected the prohibition in use of these as pesticides or …
Using National Wetlands Inventory Maps To Quantify Whooping Crane Stopover Habitat In Oklahoma, Dale W. Stahlecker
Using National Wetlands Inventory Maps To Quantify Whooping Crane Stopover Habitat In Oklahoma, Dale W. Stahlecker
Proceedings of the North American Crane Workshop
Three stratified random samples of the 416 National Wetland Inventory (NWI) maps within the western Oklahoma portion of the Wood Buffalo-Aransas whooping crane (Grus americana) migration corridor were used to evaluate the availability of wetland roost sites. Wetlands were eliminated as potential roosts if visibility was obscured by vegetation or slope, or if certain human activities occurred within 100-800 m. Thirty percent of all wetlands >0.04 ha passed map review, but only 7% passed when ground truthed. NWI map review was a poor predictor of suitability (33 % correct) but a good predictor of unsuitability (97 % correct). …
Behavior Of Whooping Cranes During Initiation Of Migration, Thomas V. Stehn
Behavior Of Whooping Cranes During Initiation Of Migration, Thomas V. Stehn
Proceedings of the North American Crane Workshop
Whooping cranes (Grus americana) observed immediately before the initiation of migratory flights exhibited increased alertness, wing ruffling, and head tilting. Seven observations at Aransas National Wildlife Refuge (NWR), Texas, indicate that the departure of 1 group of whooping cranes may influence other nearby cranes to start migration, even though later departing groups may fly separately.