We can conjecture that it may be advantageous for a particular bird to be known to its neighbors or its mate.
My uncommonly well-made sneaker lasted 5 years. Its mate did not.
What can I get for you mate?
successful males may mate with many females
Some of my classmate are now my workmates. A flatmate
Domestic animals shouldn't mate with the wild ones.
The two classmates maintained their friendship for the next forty years.
A male bird usually has brighter feathers to attract a mate.
Christopher Columbus was notorious for repeatedly snoozing his alarm clock by hitting it with his fist. Unfortunately, his "alarm clock" was usually his first mate.