Mute swan pairs mate for life (photo from Wikimedia Commons)

22 November 2025

“Birds are classically among the most monogamous of all organisms,” wrote Frank B. Gill in his textbook Ornithology.  90% of bird species form a pair bond in which they commit to work together to raise their young. Swans are well known for it.

Monogamy is rare in mammals. Humans are among the mere 3-5% of mammalian species that form pair bonds, but we didn’t always behave this way. Very, very long ago humans had a non-monogamous breeding system but started forming monogamous relationships to stop incoming men from killing rivals’ babies.

Fortunately that type of rivalry is lost in the mists of time.

Humans still value monogamy, which for our species is a spectrum from lifelong to short commitments. People pair up, form partnerships, marry, perhaps divorce, perhaps remarry.

Maintaining a long marriage is hard work. People change over time, sometimes incompatibly. So my husband and I are lucky. We’ve weathered the ups and downs and are even closer now than we were 20 years ago.

A good man is hard to find. I’m very lucky. Today we’ve been married 50 years.

wedding 1975