I'm not much for birding actually but recently there have been a couple of raptors hanging out in the neighbourhood, hassling the crows and other local birdlife. From what I can discern from my Peterson's, they seem to be immature Sharp-Shinned Hawks (Accipiter striatus).

Correction: I am told by a an actual birder that based on it's size it's more likely a Cooper's Hawk (Accipiter cooperii), which is apparently more prevalent in urban Vancouver .