First Post And A Mystery Bird

I have decided to start a diary of all the comings and goings of birds and other wildlife I see while sitting on the back porch, or walking the neighbourhood. 

 For years now I've been fascinated with the species of birds that show up at different times of the year for and then move on. so I'm going to log the activities and see who shows up and when. 

 Also, we have such a variety of cloud formations out here on Vancouver Island the result of living next to mountains and the ocean  so I'm going to capture the more impressive ones I observe. 

 So, here I go, first post, and my first puzzle. I have no idea what species of birds I’m seeing. I'm going to have to start learning already. 

 This morning, around 9.30, they were flying and diving all over and settling on branches and thistles momentarily before heading off, keeping to the bush line in the foreground.

 No chance to actually study them, let alone take a close up photo, they were too quick. Sparrow-like in size, brown feathered, flying quickly in dips, from one tree to another. I think I caught a dark cap on their head. They liked the willow but also perched on the spindly weed trees in the ditch. 

 I first noticed them a couple of days ago. Very audible, constantly tweeting, and gathering in a group, at least a dozen I estimate. Heres a video, I'll keep trying for a clear shot, or a more precise description.