Saturday last was World Sparrow Day. You probably missed it. I found out a day late.

The sparrow being honored was the House Sparrow, one of more than 40 species in that family. House Sparrows generally are ignored by birders unless as a check mark on a list. House Sparrows deserve recognition, and even concern, for a couple of good reasons. And I say this as someone who has pulled sparrow nests from my bluebird nest boxes, then killed those intruders. (I think in the future I will work to simply keep them at bay.)

What's the big deal? As was pointed out by more than one commenter on the email list BirdChat, House Sparrows, along with pigeons, are many people's only contact with birds. House Sparrows are bird ambassadors in the city, particularly in its inner parts. Without House Sparrows, many city residents have less contact with wild animals than they already do; such contact can be almost nil.

Second, in Great Britain, from which our sparrows were brought in the 1800s, this species is on a steep decline. There was a loss of 71 percent of the estimated population from 1977 to 2008. No one knows why this is happening. This is scary. What is the cause of the loss? What species birds are next? Is this an indication of our future, of an environment headed in such a direction that now House Sparrows are having survival problems? (I know, that's alarmist. The small chance is distant and remote and small, right? Then there is the canary in the coal mine.)

House Sparrows are tough. They have been recorded as living in coal mines in Great Britain, and breeding high on mountains. They are the most human-adapted bird species on earth. If we can't keep the planet hospitable for them, what then?

House Sparrows, male above, female below. They're really rather handsome birds.