Question

1. why the birds were unusual that evening?​

Answer 1

Answer:

A primary reason male birds sing is to attract mates, and it has been found that unmated mockingbirds and nightingales sing at night more frequently than mated males. ... Being heard clearly is important to birds for mate attraction, territory defense, and communicating threats to other individuals.

Answer 2

Answer:

Many birds that normally sing during the day have been observed singing at night. The culprit has usually been thought to be light, cities being so bright at night that the birds stop chirping later or start earlier.