Be Mine!
Robins and Their Mates

As days grow longer in spring, robins suddenly develop an urge to move northward, to separate from other robins and live on a territory, and to build a nest and raise babies. But they can’t separate from every single robin! In order to raise babies, they need to choose one particular robin who they’ll allow on their territory to be their mate.

How does a robin choose this one special bird? How long do mated robins stay together? Does the bond last for life?

Female: Maid Marion Male: Robin Hood

Home, Sweet Home! Claiming a Territory
The first thing robins do in spring is to arrive on and claim a territory. We can easily observe males doing this; they sing as well as chase other males off the territory. Females are much quieter, but equally determined to defend their territory against other females.

Females arrive on territory a few days to a week behind the males. Most of the males’ territorial battles are over by then. Females probably select a territory by how good the habitat looks, but often notice the territory in the first place because of the male’s singing. When a female enters a male’s territory, he doesn’t chase her away. He does notice her, often singing even more. If she likes what she sees and hears, she starts looking around for a good place to build a nest. It turns out that even though robins are devoted mates, they first fell in love—not with each other but with the territory!

Working Together
The mates stay closely bonded during the summer season
. Each is responsible for certain jobs as they raise their babies. The female builds the nest, though the male often brings her some of the materials. He continues to sing as she lays the eggs and incubates them. When the babies hatch, both the parents get busy feeding them. When the babies fledge (leave the nest), both parents continue to follow them and feed them for a few days. But then the female gets busy building a new nest and laying new eggs. While she incubates the new brood, the male continues taking care of the older babies. He leads them to a stand of trees in the evening where they will roost with other robins. By the time the new eggs hatch, the older babies are ready to be on their own, and the male is able to help feed the new babies.

Through the Seasons
Robins nest twice and sometimes even three times in a single season. By sharing responsibilities, they can raise as many as twelve healthy babies every year. But as the last brood fledges and becomes independent, the male and female feel less attached to the territory. They grow restless to travel and associate with other robins. There’s little evidence that a mated pair remains together during winter. But when spring comes again, if he’s survived, the male returns to his familiar old territory.

Next Spring: Together Again?
Back around his old territory, a male knows all the best hiding and feeding places, and has a lot of experience spotting intruders and chasing them away. That means he has a better chance than any other robin of defending the exact same territory year after year. A few days later, if she survived the winter, the female returns to where she raised babies the year before. Like the male, her experience gives her a better chance than other females to keep the territory.

Do the two birds recognize each other? No one knows for sure. But there are many cases of robins mating with the same bird for several years in a row, and their experience probably helps increase the likelihood of success in raising their babies.

If the male does not return, another male will discover and take over his territory. When the female returns to the territory, she will accept the new male as her mate. If the female doesn’t return, the male will accept any other new female attracted to the territory.

A Case Study in Robin Mates
"Robin Hood" is a male robin who established a territory and has returned to it each year for four springs. "Maid Marion" appeared on the territory during Robin Hood’s third year, and also returned the following year. Read more here:

Journey North's robin expert Laura Erickson calculates that next year there is

  • a 25% chance that BOTH Robin Hood and Maid Marion will return,
  • a 25% chance that NEITHER Robin Hood or Maid Marion will return, and
  • a 50% chance that ONE of them will return.

What If One Robin Dies?
A sad thing happened in Laura Erickson’s yard last summer. She heard loud squawking and ran out to see her favorite male robin being eaten by a Cooper’s Hawk, and the poor robin was still alive! The robin’s mate kept flying in the hawk’s face, but the hawk hunched over and kept eating. Two crows came down to investigate. They stood quietly several feet away, waiting just in case the female succeeded in driving off the hawk, so they could finish off the male. Even after the male died, the female kept squawking and flying at the hawk until it finally flew away. Laura was very sad, because the dead male robin had come to her yard for several years, and always sang at the top of her spruce tree. She was shocked the next morning to find another male robin on the territory; the female quickly accepted him as her new mate. He helped her raise the babies she already had, and then mated with her and helped her raise those new babies.

Try This! Journaling Questions

  • Did you ever see an advertisement for something you’d never known about, and then decided to buy it when you looked at it in a store? Why do you think the robin’s song is sometimes called an “advertisement” for a female?
  • One scientific study showed that about 75% of all fledgling robins die before November their first year. Of those that survive that long, about half die before the next November. About half of all 2-year-old robins die each year, and about half of all robins of every other age die each year, too. If this is true, and if 200 robins were fledged in a town one year, how many of the fledglings would be alive in November? How many would be alive the following November? How many would be alive the following November? How many years would it be before all these fledglings had probably died?
  • Does it make sense that half of all 6-year-old robins die every year, and half of all 1-year-old robins die every year? Birds that are old have the same chance of surviving from one year to the next as birds that are young. Can you explain why? Based on that data, how much of a chance does a robin have that his or her mate will return to their territory the next spring?

Answers >>