1 mature female NG

29 March 2008 11 AM. RVP
1 mature female NG; EOB- 200 feet overhead; then rising to 400-500 feet. The bird never flapped. OT- 3 minutes. I am sure I have seen this bird before; same location. The bird had some dark streaking. The under tail coverts were bright white and fluffy; streaming out to the sides and also streaming over the top of the base of the tail. The under wings were very contrasty; black and white. The wing pattern was the same throughout. Winds were at 15 miles per hour.