We feed a lot of strays and call them by whistle but whenever there's a new dog they always tilt their head.

It seems more likely they do it for concentrating during memory recall

Quora's not a great resource anymore. It's just peoples' opinions boosted by an echo chamber.

This is probably the only good content that existed on there before it became a cesspool: http://qsf.cf.quoracdn.net/best_of_quora_2010-2012.pdf