| The objective of this study was to determine whether low-level flying military aircraft affected the reproductive success of Osprey (Pandion haliaetus), and if so, to determine the optimal avoidance distance to minimize these effects. I studied 49 nests in 1995, and 68 nests in 1996 within the military low-level flying zone. Nest occupancy, clutch size, number of hatchlings, and number of young at 41 days of age were assessed at each nest. GIS flight track records provided frequency of aircraft at given distances and altitudes from the nest. Logistic regression analysis assessed the impact of flight frequency in four distance categories and four altitude categories on Osprey reproduction. The frequency of flights within each category were not accurate predictors of Osprey reproductive output. Nests were then randomly assigned to a buffer-zone radius of either 0, 1.85, 3.7, or to a control of 7.4 km, and reproductive output was compared among treatments, and between years. No significant differences were discovered among the reproductive parameters within either 1995 or 1996, but reproductive output was significantly higher in 1995, likely due to adverse weather conditions experienced in 1996. |
