It’s mainly birds that pair for life - in some groups such as seabirds this commitment is the norm, while other, often shorter-lived creatures, employ an endless box of tricks to ensure they get the best other half for their offspring, couple or not!
As research into animal behaviour gives us a better picture of what really goes on between pairs, scientist have discovered that some of the species that seemed monogamous have a tendency towards wandering eyes…
All loved up
As mentioned, seabirds are some of the most monogamous creatures in the animal kingdom. Once they reach breeding age they will find and mate and generally stick with them for life. If one of the pair dies the other will usually move on and raising a chick tends to require both parents in these harsh coastal habitats. However, this does vary within species – the loyal puffin has a divorce rate of 7-13% in British colonies while in Norway colonies showed zero pairs opting to part ways!
Birds of prey including osprey and barn owl, corvids (the family containing crows and rooks) and most swans and geese also mate for life. Some have lavish displays as they reunite with their partner after a winter apart, reinforcing their bond.
Some British mammals also mate for life, including otters. Beavers, recently brought back to England and Scotland after hundreds of years of absence, create dams and lodges with their partners and form long-term bonds.
The rise in genetic testing has revealed a lot about species we once thought of as monogamous. Jackdaws were long thought to mate for life, but a bit of testing showed that there was some cheating going on between pairs, although they did stick together to raise young (known as socially monogamous). Being part of a partnership was still important in many cases, with mating outside the pair a form of insurance for their young.
When species are stressed, by unusual environmental conditions or a lack of food for example, they were more likely to ‘cheat’. When conditions got tougher, they would search outside of their pair for the mate that would give their offspring the best chance of survival. So sometimes it does pay to wander, at least in the animal kingdom.