@Rick: My last visit there were still a lot of Tree Sparrows throughout the baselands. Chipping Sparrows traditionally arrive mid-April, so with many migrants being delayed this year, it's an unlikely occurrence this week - but hey, in the Wet Woods you just never know what you'll find! Also, there are a few reports of Chipping Sparrows on eBird not too far away from the GTA so I guess you shouldn't really rule out your i.d. just yet. Hope to see you somewhere soon.
@Elias: Oh how to describe our beloved Leon? How 'bout an "elder statesman" of the everyday birder? Not a prominent member of any fancy clubs, but a life long birder and butterfly lover, well into his late 80's, who probably logs more hours in the field than any other birder I know. A great source of birding wisdom. As spring migration heats up, you can find him in the Wet Woods most mornings before he changes gears and heads elsewhere to look for butterflies. Our light-hearted notion of a "Leon Sighting" is really an expression of relief for his well-being whenever someone bumps into him for the first time in awhile.
-kris