About us: We own the Wild Birds Unlimited nature shop in East Lansing, Michigan,
a store that provides a wide variety of supplies to help you enjoy the birdwatching hobby.

This blog was created to answer frequently asked questions & to share nature stories and photographs.
To contribute, email me at bloubird@gmail.com.

Tuesday, April 6, 2010

Fascinating Facts About The American Robin

Now that the weather in mid-Michigan allows me to have the windows open, I enjoy the American Robins' dawn chorus, their energetic running across the yards in search of food, and their songs at night. I hope other people do too. The following are a few fun facts about the robins:
  • Worms only make up about 15%-20% of the summer diet for American Robins. The rest of the diet is made up of other insects, fruit, nuts, and berries.
  • Contrary to popular belief, American Robins don’t find earthworms by hearing or smelling them. Robins find earthworms by cocking their head to one side, independently using each eye to look for visible signs of worms.
  • Most of the earthworms found in North America today did not exist prior to European settlement. They were imported mainly from Europe by early settlers. The worms or worm cocoons traveled in the rootstocks of plants brought by the settlers from their homelands. They were also release into the new world through soil that was used for ship ballast that was discarded after the voyage to the new world.
  • Robins can be attracted to a feeding station by offering mealworms, suet, nuts, fruit and a birdbath. It’s especially fun to offer mealworms during nesting season when the robins can stop and pick up a mouthful of tasty worms to take back to their babies. They will fill their mouth until you think nothing else could possibly fit inside and still continue to try to pick up more, dropping some in the process and then trying to pick up more.
  • On average, over 50% of all nesting attempts by American Robins fail to produce young. Out of the successful nesting attempts, only ¼ of the fledglings will survive until November. Robins live on average about 1 ½ years, but, according to bird banding records; the oldest known Robin found in the wild was almost 14 years old.
  • Robins typically nest from April through July and can have 2-3 broods in a season. The female does the nest building and incubates the eggs alone. Upon hatching, both parents feed the average brood of four young.
  • Robins usually return to the same area to nest each year and may occasionally use last year’s nest again after some renovation.
  • Robins are particularly vulnerable to pesticide poisoning due to their preference for foraging on lawns. Please don’t use poisons on your lawn.
  • During breeding season, male American Robins grow black feathers on their heads to attract females. Once the mating season is over, these feathers are lost.
  • A group of robins are collectively known as a "worm" of robins.


Vetsy said...

Thank you for this informative post on the Robin and setting the record straight. I too" once thought that Robins found their food by cocking their heads to one side and listening for worms.

Thank you also for the feeding tips, such as the meal worms and suet.

Anonymous said...

i am so surprised that the robin is so fragile. Thanks for the feeding tips.

Blair Cessna said...

I didn't know earthworms were imported from Europe. Very interesting. Thanks for sharing.

Wild Birds Unlimited Mid-Michigan said...

A lot of people don’t know that the beloved earthworm may be bad news for our northern forests. Seven different species of European earthworms were brought over in the last century by our European ancestors. And decades of anglers dumping their worms also helped spread the invasion.

The slow-moving earthworm invasion is causing a devastating effect on native plants. The Great Lakes Worm Watch is a website devoted to the environmental threat. For more information go to http://greatlakeswormwatch.org/

Thanks for the comment, Sarah

Anonymous said...

Why do some birds like the robin and Chickadee only live a year or two, while other birds can live longer? That is so sad.

Wild Birds Unlimited Mid-Michigan said...

A definitive answer to the evolution of lifespan is still a mystery. Scientists believe that birds’ observable characteristics: such as their development, physiological properties, and behavior (like nest building) is a result of the expression of their genes and the influence of environmental factors.

Another theory on why some birds live longer than others is size. Because smaller birds tend to be more prone to predation and other dangers, their life may be cut short. The average lifespan of the littler bird is only a year or two while the bigger birds average around 25-50 years. There are a number of cases in which smaller animals within a given species live longer in captivity. For example it has been recorded that some captive House Sparrows lived for 23 years, and Northern Cardinals 22 years.

At what age a bird reaches sexual maturity might also influence longevity. While chickadees, sparrows, and goldfinches can mate at one year, crows, hawks, and eagles may take up to five years to reach sexual maturity.

Although life expectancy in birds might be correlated closely with size, further information is required. So in addition to collecting data directly by banding and recapturing birds more research needs to be done.

In fact one recent study already found that tropical birds, leading a slower life and expending less energy, tended to live longer than birds that had to survive harsh winters. The researchers traveled to Panama where they captured tropical birds and measured their basal metabolic rate (BMR) – the minimum amount of energy they expend at rest, solely to maintain their vital bodily functions.

They compared these measurements with the BMRs of temperate birds. They found that tropical birds used about 18 percent less energy, as measured by BMR, when compared with temperate birds.

The researchers also tested neotropical migrants – those birds that live in the tropics much of the year, but migrate north to temperate climates such as the United States and Canada to breed. Results showed these birds expended more energy than those species that live year-round in the tropics, but still used less energy than birds that were permanent residents in colder states like Michigan.

Scientists believe that tropical birds may have a slower pace of life because it fits with the rest of their life history. Tropical birds, compared to those from temperate regions, tend to live longer, and produce fewer offspring which develop slowly and mature relatively late in life.

Makes me glad I feed the hardy birds that choose to stay year-round in Michigan. As the temperatures dip and natural food sources may become covered with snow or locked in ice, I know that the supplemental food and water that I provide is more widely appreciated and has a bigger impact on the birds’ survival.