Do all birds mate for life?
Around 90% of birds are considered monogamous, but the definition is a little different than we might think. It’s really more that most birds are socially monogamous, rather than sexually monogamous.1
This means that the birds pair up and the male has an active role in taking care of the offspring. This can last for just a season or multiple years. But this monogamous relationship is purely social and does not mean that the birds won’t reproduce with other birds, too.1 These other relationships are called extra-pair copulations and they happen even in very dedicated bird relationships. Sexual monogamy is rare.2
The reason for this is that in nature, passing on genetics is the most important thing. Some species find more of a benefit of staying sexually monogamous while others find that passing on their genetics as much as they can to be more beneficial. It makes sense, too – after all, when a male or female reproduces with multiple partners, the result is more genetic variation among the offspring.2
The main two reasons you’ll find monogamous pairings are: proximity and parenting. If it’s hard to find a member of the opposite sex in a species, they’ll usually settle down with the first mate they find. If an environment is dangerous and the offspring will need more of a helping hand to survive, then a pair will most likely bond together permanently.2
For most birds, their bond with a mate only lasts for one breeding season.2 But some are known for their monogamous relationships with their partners that last as long as they live. Some of them are:
Did you catch our blog on how birds regulate their body temperature? Read it here.