While American robins are increasingly common and found all over the country, there are plenty of things you might not know about them.
These cheerful singing birds are foragers that primarily eat earthworms, invertebrates, fruits, and berries.
They like fermented berries that thaw after a long winter and eat so much that they can become intoxicated. They also eat up to 14 feet in length of earthworms daily!
Robins are so popular that they are the state bird in 3 states, the theme of songs, and are often confused with other red-bellied birds.
In this article, you’ll also learn how to tell the difference between a male and female robin, and how they help scientists determine the health of ecosystems.
Read on to learn about these facts and more about American Robins.
1. American Robins Can Get Intoxicated On Fermented Berries
American robins are omnivores and active ground feeders. In the spring and summer, they forage insects and worms. In fall and winter, they eat more fruits and berries.
Yeast fermentation occurs naturally with the sugars in berries after they have been overwintered and thawed. This creates a fermented berry that is like drinking alcohol.
Robins will experience fermentation toxicity when they gorge themselves on fermented blackberries, juniper berries, crabapples, and more.
They become tipsy and unable to fly when they eat a large number of these fermented fruits.
2. They Eat Up To 14 Feet Of Earthworms Daily
Robins tend to stick to the ground foraging and eat softer foods such as earthworms with their short straight beaks designed for this task. Robins can eat as much as 14 feet worth of earthworms daily.
However, worms and other invertebrates are only about 40% of their diet and fruits and berries are the remaining larger portion.
3. American Robins Are The Largest Thrushes
American robins (Turdus migratorius) are the largest North American thrushes, with lengths of 7.9 to 11.0 inches and weights of 2.7 to 3.0 ounces.
These birds are often used as a reference when comparing the sizes of other birds, stating them to be “larger or smaller than a robin”.
They belong to the Turdidae family along with other thrushes in the genus Turdus, such as bluebirds, solitaires, and fieldfares.
Generally, thrushes are songbirds with slender bills and legs covered with a single, long scale (instead of multiple ones).
4. American Robins Have Look-Alikes
There are several subspecies of American robins such as T. m. achrusterus and T. m. caurinus which largely present with different colorations or patterning.
However, there are other birds often mistaken as robins due to their red-colored chests.
These include the following:
- Red-breasted nuthatch
- Spotted towhee
- Varied thrush
- Black-headed grosbeak
- Common redstart
The American robin was named by early American settlers due to its resemblance to the European robin (Erithacus rubecula). However, they are not related. European robins are in the family of Muscicapidae.
The term “robin” is used in other non-related birds’ names such as the following due to their resemblance to American robins:
- Indian robin (Saxicoloides fulicatus)
- Bush robin (Tarsiger johnstoniae)
- Pekin robin (Leiothrix lutea)
- Magpie-robin (Copsychus saularis)
- Scarlet robin (Petroica boodang)
5. The Time Of Day & Seasons Impact What The Robin Eats
Robins typically eat more earthworms in the mornings of spring and summer when they are more plentiful. Morning dew drops and periods of rain also bring worms to the surface for a readily-available snack.
As the day gets later as well as in the colder seasons of fall and winter, robins consume fruits and berries. Berry availability depends upon the climate and the types of berries that grow in different seasons.
6. They Have Monocular Vision
American robins not only use their sensitive hearing to listen for worm movement vibrations, but their eyes can also detect subtle shifts in the ground created by earthworms.
They have monocular vision, meaning that they can independently use an eye on one side of the head to locate an item.
7. Robins Are Vulnerable To Poisons & Predators
On average robins live about 2 years in the wild but have a population of over 3000 million. They have a short life often due to pesticides and predators.
When any pesticides are used around residential and business buildings, they are often applied to grass. As a result, this creates poisoned food sources for many birds, including robins.
Other threats to robins (and their eggs and hatchlings) are predators, which include cats, foxes, hawks, snakes, blue jays, and American crows.
8. Robin Have A Distinctive Red Breast Pattern
Male and female robins have slight color differences. They both have red-, orange-, rust-colored chests and light-colored eye rings. However, males are brighter than females, who have a subdued coloring.
Males have dark black heads with brighter toned eye rings and chest color. Females have a gray head, like the rest of their body, and a paler-toned chest color and eye rings.
Juvenile robins look more like females, regardless of gender. They also have spotted plumage before they have their first (annual) molt.
9. Males & Females Have Differently Colored Beaks
Since males and females look very much alike, they can be hard to tell apart. However, if you can see their bill, you can more quickly identify what gender the bird is.
Males have bright yellow beaks, and females have a duller yellow with a black tip.
The following can help you remember this:
“If the beak is yellow, it’s a fellow.
If the beak is black, it’s a Jill, not a Jack”
10. Not All American Robins Migrate
Not all American robins migrate depending on where they live. Northern populations often migrate south, but they will stay local if there are adequate food sources.
They may travel as groups to hunt for berries, flocking and roosting in trees together at night.
If they do migrate, they are capable of traveling thousands of miles. American robins call many places home, both in the wild, in forests, and in towns and cities.
In the winter, you are not as likely to see them foraging on the ground, but they may be around up in trees.
11. Male Robins Dance & Sing To Court Mates
Male American robins tend to pair up with different females each spring.
When it is breeding season, males put on an impressive show by shaking their wings, fluffing up their tails, puffing their throats, and belting out a melodious song.
Males often sing at dawn to attract fertile egg-laying females. They also sing to claim territory. Robins use a syrinx, their voice box, to create high-pitched and variable warbling sounds.
12. Female Robins Pick The Nesting Sites
Female American robins pick nesting sites in various places such as thickets, tree branches, on the ground, on top of light fixtures, in potted plants, and so on.
They build cup-shaped nests using a variety of materials such as straws, twigs, and dry leaves. Mud helps hold it together and it is lined with moss and feathers.
The completed nest is about 6 to 8 inches in diameter and 3 to 6 inches deep.
13. They Sort & Remove Brood-Parasitic Eggs
Brown-headed cowbirds are brood parasites, laying their speckled eggs in other birds’ nests, including a robin’s.
If these eggs hatch the nestlings compete with the other babies for food and care, with some of the original nestmates dying.
Interestingly, robins can often recognize and remove these unwanted eggs before they hatch.
14. Robin Chirps Are Higher Pitched To Combat Noise Pollution
The increasing amount of competing noise in cities and areas with wind turbines has caused robins to alter their chirps.
Robins use their chirps to communicate and when other low-frequency sounds interrupt their communication they change it by using higher pitches.
Check out this video of a robin chirping:
15. They Are Used As Markers For Environmental Health
The health and population trends of robins help ornithologists detect environmental concerns.
For example, pesticides in soil and groundwater were accumulating in earthworms, and as the robins ate them, they were poisoned.
In the mid-1990s, robins and other birds were rapidly dying from the use of the chemical pesticide DDT. This led to a ban on the substance and the bird population began to recover.
If the abundant and widespread numbers of robins decrease, it tells scientists that something is wrong in the local ecosystem that needs to be investigated.
16. Roosting Groups Are Communal
Robins will roost together in large groups, with as many as hundreds of thousands of birds.
In the summer, females sleep at the nests, and males roost together. Juveniles will join the males as they become independent. Females join roosts once they are done nesting.
17. Robins Will Fight To The Death Over Territory
Robins are territorial with each other over mates and nesting areas. Typically the fighting is to show a display of strength.
They use their claws and beak to scratch and peck at each other. If a perfectly aimed peck is delivered to the spinal cord the injured robin will die.
18. They Produce Up to Three Broods Each Year
American robins produce up to 3 broods each year of 3 to 5 eggs.
About 40% of these nests successfully produce offspring, and about 25% of the fledglings survive the first 6 months.
The female incubates the eggs for 12 to 14 days. Hatchlings remain in the nest for 14 to 16 days to develop flight feathers before leaving.
19. Robin Eggshells Are Blue
American robin’s eggs are a lovely vibrant blue or bluish-green color (cyan).
The female robin’s blood has hemoglobin and bile pigment (biliverdin) that turn the shells blue as they are formed. Higher biliverdin levels create brighter blue eggs indicating a healthy female.
20. Fledglings Stay With Their Parents
Once the chicks have left the nest, they stay with their parents for another two weeks. Their parents continue to feed them until they can fully fly independently.
If they survive to the age of 1 year they are mature adults and capable of breeding.
21. Female Robins Eat The Discarded Eggshells
After the hatchlings have come out of their shells, often the mother will eat the shells. This gives her a boost of much-needed calcium. This helps her replenish her strength for the next brood as well.
While robins do not typically eat bird seed, avid bird watchers will also add eggshells to bird seed mix for the same purpose for all types of birds.
22. American Robins Will Feed Other Chick Species
Even though robins are territorial towards each other over nests, they are not necessarily territorial towards other species of birds.
Robins’ parental instincts kick in, and they will help feed chicks and fledglings of other species such as the song thrush, spotted flycatcher, and willow warbler.
23. They Fly Faster At Higher Altitudes
American robins can fly from 30 to 36 miles per hour.
They tend to move faster in clear skies at higher altitudes as compared to flying around a neighborhood.
24. American Robins Are Highly Recognized
Robins are so common that they are well-known birds to many people. It is the state bird in 3 states: Wisconsin, Michigan, and Connecticut. Its likeness can be found on flags, coins, and more.
For many robins are a sign of spring and represent new beginnings or renewal. Folklore and legends tell of robins as symbols of peace, safety, or nurturing.
There are even songs using the robin’s name such as “Rockin’ Robin” recorded by Bobby Day in 1958.
The beloved American robin is a welcome sight to tell us that spring is coming. These birds will fight each other fiercely over territory, yet use strong parental instincts to care for their young as well as the chicks of other bird species.
While males and females look a lot alike, females are duller in shade and have black tips on their beaks. Many other species of birds are often confused with robins since they too have red bellies.
The health of robins and the strength of their populations help scientists track and discover if there are environmental health concerns, especially those that are leaking contaminants or toxins into the soil.