This particular species is very difficult to photograph on a good day just because of their size, but they take a perverse pleasure in teasing any poor schmuck that tries to capture them with a camera by constantly stopping long enough to sucker the shooter into setting up the shot only to have the bloody thing move right before releasing the shutter. The reason I was able to do it is quite simple. There was a crowd of 'em and they tend to bunch up together and with other species making it more difficult for them to simply walk which seems to be their favorite tactic.