Strangely this is so similar to word for bird in my mother tongue "Marathi", we call it a "Pakharoo" (pronounced almost like this one)
It would be nice to know the motiv(ation) of your intererst for Spanish language. Admirable, having so different alphabets, Many of us get troubled with the same alphabet.
My initial guess was that the word was borrowed from Arabic, because both Spanish, and Marathi, have borrowed from Arabic. But I looked up the etymology of "pájaro" and it goes back to a Latin word, so I think it's just a coincidence.
Can "pajaros" not also mean "parrots"? I've always learned "aves" for "birds".
Nope. Parrot is generally "el loro". "Pájaro" is the word you would most often use for "bird", unless you are being a bit more technical and speaking about the particular species, etc...
"El quetzal es un ave que para sobrevivir necesita un bosque nuboso"