Not sure it is necessary as the captive crow may communicate it status (croaking "I'm trapped" or "I'm free") with this one, but it would be an insight.

I'm not sure I understand. I'm referring to the assailant crow that allegedly flew around the building and up to the balcony while the original poster was indoors ascending to the eighth floor. I'm not sure how it can be known, given the details in the post, that the assailing crow wasn't a third crow other than the two on the balcony.