Translation:By chance the parrots are drunk.
That chance is 99%
At this point, it's a pretty safe bet.
"OK, who gave the parrots undiluted wine to drink?"
By chance my ass.. xD
Yeah, it's the Duolingo owl... in this course he keeps getting the parrots drunk.
By chance... They've been drinking for the entire course!
I get the sense that it's less by chance and more by... intention. deliberate, customary intention.