I heard that expression first when I was a school kid.
It was back in the old country. With English as a special, er, second language, I originally misheard that as "one sparrow doesn't make a summer."
I figured that in England, where it was always cold and damp, only in the summer they get to see and hear birds and, therefore, an accidental sighting of a sparrow does not mean it is summer. Unlike my old part of the world where crows crowed every single day.
I was all ok with it, until I was corrected by the English teacher. She said it was not "sparrow" but "swallow."
"Swallow"? Do people not swallow in the winter? And one swallow does not make a summer? Had I known WTH and WTF back then, I would have written that all over my English notebook! ;)
By correcting me, the teacher confused me. I didn't have the guts to ask her what swallow meant in that sentence! I, like most kids, typically stayed away from asking questions.
It was much later that I came to know that in this case "swallow" was a bird.
The misheard word apparently did not screw up my understanding of the idiom.
The more I recall my life, the more I am always amazed at my own idiocy.
The sighting of a bird brought back those memories. It is summer here and a bird flew into the yard and hopped around on the ground. I had no idea what bird that was. I stood there watching that tiny squawking life until it took off to report to whoever that the mission was accomplished.
In the old country, rapid urbanization has led to people living in tight quarters in megacities. The last time I was there, mother went outside their flat with a couple of small balls of cooked rice. She then called out for crows. Nothing. Nada. Zippo. Zilch. Not a crow to be found or heard.
I helped her out with crow calls of my own. I wondered whether there was an American accent in my bird call ;)
Not a crow in sight.
"These are city birds. They want chips and pizza," mother said and gave up waiting for crows.
The pigeons on the neighboring building couldn't care about all this drama. It is always summer for them.