A black and metallic UFO above Sugar Land, Texas

On January 11, 2013 at 1:17 PM, a black and metallic unidentified flying object has crossed the sky, over the city of Sugar Land in Texas. By watching photo, we can think that it’s just a bird. But this explanation seems not credible … What do you think?

Witness report:

I was driving south on 59s on 1-11-2013 @ 1:17pm and I noticed a dark strange shaped object to my left, moving kind of oddly from se to nw over 59s out of sight behind a tree line. When I first saw it I thought "what the heck is that thing? Its bigger than a helicopter, no blades, dark, and moving not like a plane nor helicopter. What is that thing?" The dark oddly shaped object moved like sputtering and a tight zig zaggy sideways and vertical path. When I first saw it I knew it was unusual and immediatly I reached for my phone in my purse and since it was moving fast I knew I didnt have much time so as soon as my camera mode came up I zoomed in as much as possible right away and snapped a pic in the direction I last saw it. I got one pic of it before it disappered behind the treeline. 

I felt anxious and in disbelief and amazed because I couldnt identify what this thing was. Having lived near an airport for over 30 yrs and being used to planes and helicopters day and night, I was shaken that at the distance this thing was from me I couldnt tell identify if it was a plane or helicopter.
I could not identify it as a plane nor helicopter.