What has happened to our White-throated Sparrows?

The lilting song of “Oh Sweet Canada, Canada, Canada,” usually so ubiquitous in the spring at our house, is strangely missing, and the feel around here is empty because of it. The White-throated Sparrows usually stay around well into May, but I haven’t had any for at least three weeks. In February they were still here as described in this post of "Spring sounds are starting to pop up," but over night they vanished.

Rick took this photo last spring. This spring, the 

White-throated Sparrows have gone unaccounted for.

I don’t know if their early departure is from recent habitat destruction about a mile from our house, or if they just took flight north way, way early because they were tired of our digs. Has anyone else noticed diminished numbers, or is my yard’s population an anomaly?

I really miss these songsters. Spring is just a bit empty 

without their lovely song. I look forward to it every year!

Another bird missing from our ranks is the White-crowned Sparrow. We had a few in February, but they have disappeared early also. Their numbers are never as big as the White-throated and we only had a few popping up every now and then this winter. A couple years ago, they were regular visitors, but this year, they were more sporadic.

Rick also capture this shot last spring. No 

White Crowns have been around since February. 

A small woods was taken down in our area, and we lost 3 huge bushes around the feeders last autumn due to the drought, so maybe habitat destruction has something to do with it. Are they sensitive to Starlings? We had a very large flock move in late winter. The other birds don't seem to mind, but maybe they are more timid? I have no idea...but something is up.