Answers from the Robin Expert
Spring 2011

Teaching Suggestions

Special thanks to Laura Erickson for providing her time and expertise in responding to your questions! Look for answers to questions like these:

  • Why are robins so noisy at dusk when they are preparing to roost?
  • What makes the eggs blue?
  • What is the average lifespan of a robin?

Laura Erickson

Questions and Answers

From: Toledo, Ohio

Q: Have you ever heard the answer to the question what are the robins singing? My Great grandmother told me when it was about to rain that they were saying "gonna rain Peter." I am 72 years young and she was born in 1876.

A: I have a book from 1904 by F. Schuyler Mathews titled Field Book of Wild Birds and Their Music. In it, Mathews describes the robin song as “Cheerily, Cheer up, cheer up, Cheerily, Cheerily, Cheer up.” In Frank Chapman’s 1895 Handbook of Birds, he writes, “The songs and call-notes of the Robin, while well known to every one, are in reality understood by no one, and offer excellent subjects for the student of bird language. Its notes express interrogation, suspicion, alarm, caution, and it signals to its companions to take wing; indeed, few of our birds have a more extended vocabulary.” Your great-grandmother may have read these books when she was a young woman. Interestingly, robins often do sing before a rain, perhaps responding to changes in barometric pressure or something else, so her interpretation was quite apt.

From: Dunedin, Florida

Q: I know that Robins migrate past my house in Dunedin FL in February. They fly faster (15-18 mph) than they do when in the backyards. How long can they continue this fast pace without refueling and resting?

A: Believe it or not, we don’t know! We do know that some of them may occasionally cover one or two hundred miles in a day, but overall in spring, most of them make rapid flights by day, heading north, while looking carefully below for fruit trees or thawed ground where they may find worms, and take many breaks for food even during the peak of migration. And because they migrate by day, they can spend the night sleeping.

Q: Do their rest stops vary in length or is there an approximation that can be used to determine the time it takes to go 200 miles? My son lives in Tallahassee FL and the robins start arriving there some 10 days to 2 weeks after we see them go by. Is it probable that these are the same robins that go by my house in Dunedin?

A: This is impossible to know for sure. There are so many robins, and they wander quite a bit during autumn, winter, and spring that few researchers invest the time and technology to color band robins to keep track of individuals. What we know about robin movements is based on watching large masses of them, not individuals. It would be splendid to track some individuals with satellite transmitters, wouldn’t it?

From: Durham, North Carolina

Q: What compound in the eggshell makes the eggs blue? Does this compound require a special nutrient in the robin's diet?

A: The eggshell color comes from pigments in the mother robin's blood! Hemoglobin from ruptured blood cells is transformed into "bile pigments," which are carried by the robin's blood to where the eggshell forms. So she doesn’t need anything special in her diet to have properly colored eggs.

Q: What proportion of the robin's diet are earthworms? Does their diet change during breeding season (ie do they have special nutrient requirements for egg laying like increased calcium intake)?

A: In winter, especially in northern areas, a robin’s diet may be 0% worms! One study, conducted in Wisconsin from Jun to Aug 1976, compared the time spent on different foraging substrates. Of 452 minutes of observation, 78% of foraging occurred in vegetation (prey captures typically involved large insects, such as adult lepidopterans and odonates, taken from the air or foliage), 15% occurred on the ground (where they would get earthworms as well as other invertebrates), and 7% occurred on fruits. A stomach content analysis of 1,169 robins found that the invertebrates they take belong to over 100 different families! Worms are important, but robins have a varied diet, which provides the right balance of nutrients for producing young.

Q: Why are robins so noisy at dusk when they are preparing to roost?

A: When I was a little girl, I thought they were all saying good night and telling one another stories about their day’s adventures. Of course, that’s not it—though sometimes I still wonder! But many of the calls they make as they go to roost are warning calls. As they settle in for the night, they are probably hyper-vigilant, looking for any snakes, screech-owls, cats, and other potential dangers that might be lurking about. They’re probably also competing for the safest roost spots.

From Rogers, Arkansas (Bonnie Grimes Elementary)

Q: What is the average lifespan of an American Robin?

A: Scientists look at lifespan in many ways. Only about 25% of robins hatched survive to be one year old, because they encounter so many hazards from the time they’re inside the egg, and then nestlings, and then fledglings, and then migrating to strange places with different dangers that they don’t expect. But once they do survive a whole year, their life expectancy goes up dramatically. One study found that most robins live less than six years, but one banded wild robin lived to be 13 years and 11 months old.

From: Western Springs, IL

Q: I just purchased some dried mealworms at Farm and Fleet. They were actually purchased to feed bluebirds, but I doubt that we will get them in our suburban back yard. Do robins like mealworms? Should I rehydrate them before I put them into the bird feeder?

A: Don’t rehydrate dead mealworms—they will quickly spoil. Very few people feed robins, so most robins have no clue about bird feeders. I’ve had them visit my feeder for live mealworms, which they have an easier time figuring out because they notice the movement. You might purchase a small container of live mealworms to mix in with the dehydrated ones until they figure it out.

From: Swift Current, Saskatchewan

Q: What species of worms do Robins most prefer/like more?

A: Robins eat a huge variety of worms, insects, spiders, and other invertebrates. A balanced diet for them requires them to take a wide variety, so they don’t seem to have a preference, except that when facing two worms, they will usually take the larger first.

Q: During cold days, would parent Robins feed their young fruit if worms/insects are not available?

A: Yes, but fruits aren’t high in protein, which is essential for growing babies. That’s why female robins return in spring a week or two after the males, and take a while to build their nest. By the time their eggs hatch, there is usually enough animal food for them.

Q: In the Winter, will Robins huddle to stay warm?

A: No, but there may be a hundred in a single tree, so there is at least a little shared warmth.

From: Romulus, Michigan

Q: Why do some robins not leave for the winter how often do they make it through the very tough Michigan winters?

A: Robins have two competing needs—to arrive first on the best territories in spring, and to have enough food to survive winter. Males are the ones most eager to get on territory in spring, and they are also the robins most likely to winter in the north. They move about quite a bit, eating fruits and moving on when they clear out the fruit from wherever they happen to be. If there are lots of fruits in an area, they may remain there all winter, but continue to move south little by little until spring.

Q: Why do some come back in the worst of weather when there is food or bugs or worms?

A: Robins have a huge hormonal need to move north when they perceive days getting longer; this need is controlled by weather, too. But the big movement of males follows the 37-degree isotherm, when nights can still be in the 20s or even teens. When they can’t get insects and worms, they pick up the last of the dried fruit from last fall.

Q: Why do some leave and some don’t?

A: For the same reason that some people like peanut butter and others don’t. Robins and other birds have a lot of individual differences.

From: Liverpool, New York

Q: A friend of mine who lives in the Fingerlakes region of upstate NY Has told me that he has seen Robins a couple of times in the past 2 weeks. I live in Syracuse and have not seen or heard any robins. Is it possible that this robin he is seeing has wintered over here or just an early, early, arrival?

A: Either is possible. Some robins do winter in the Finger Lakes region. But some males have a stronger urge to move north than the majority, and they may head north days or even weeks ahead of the bulk of robins.

From: Aurora, Illinois

Q: We had flocks (25-30+) in Aurora in Mid-January twice with heavy snow cover! Were they coming back early or do some Robins overwinter? I lived in Nashville, TN for 20 years and they always came in the spring 500 miles south of Aurora.

A: Flocks of robins do overwinter in Illinois. Interestingly, in the dead of winter you’re more likely to find flocks than individuals, because they do tend to gather in groups for the season. As long as they can find crabapples, mountain ash, and other fruit trees, they usually do fine even in very cold winters. I’ve seen them in January all the way up in Grand Marais, Minnesota!

From: Providence, Rhode Island

Q: I am a member of the RI Wild Plant Society, and have read Douglas Tallamy's book which talks about the co-evolution of native plants and animals. Since the majority of earthworms in our yards are not the native species, how is it that robins have adapted to using them as a primary food source in just a few hundred years (very short in evolutionary terms)?

A: Robins eat a wide variety of invertebrates—from at least 100 different families. They capitalize on whatever happens to be most abundant, and as worms have become abundant, robin numbers have increased, but they’re still found in northern woodlands where worms haven’t lived since the time of the glaciers. So this isn’t really a case of co-evolution as much as simple adaptation.

From: Kentwood, Michigan

Q: When male robins fight, do they actually injure each other? Sometimes the fighting seems very intense. Have any fights actually resulted in death? (hope not).

A: Sadly, once in a while, one will be mortally injured in a flight. But just as with people, most fights don’t end tragically—one eventually figures he’s going to lose and gives up.

From: Collegeville, Pennsylvania (Perkiomen Valley HS)

Q: We have planted several winterberry holly female bushes around our school. They were filled with berries in the fall, but no birds ever came to eat them and now they are all shriveled on the twigs. Are there some kinds of berries that the robins really like and others they will take only in a starving time?

A: Robins do have a few strong preferences. I see them most often in crabapples and mountain ash. But they take a wide variety of fruits. I’m not sure when winterberry holly berries are sweetest—some berries are completely ignored by birds during fall and most of winter, and then suddenly are devoured by a variety of birds.

Q: We also planted summac in our storm water basin and those berries were not eaten either. Do the birds need a whole bunch of bushes together so that they get noticed, or should we plant something else?

A: Robins notice berries when they are already living in the area or when they’re flying over. So planting them where there is a clear view from above is best. If normal flight patterns are from north to south in fall, they might not notice plants too close to the south side of a building.

From: Lovelock, Nevada

Q: We have seen so many robins in Lovelock, NV. this week - Groups of 100 or more - is that usual? Where are they going or are they staying in our valley? We live in the high desert of northern Nevada and it is still snowy and rainy here.

A: This time of year (March), robins are extremely restless, but still in their large winter flocks. So if there are 100 robins in a large city, they are pretty likely to be in just one or two flocks. Some people will see 50 or 100, and others will see none at all.

From: Fairfax, Missouri

Q: How long will Robins stay in one place when migrating? We have had thousands the last few days in our small town and I was wondering how long this would last. It is truly amazing. I'm assuming they all will move on; surely they will not all stay here?

A: They stay in places for as long as there is a good source of food. If they deplete the food, they’ll move on, but not necessarily north if the weather isn’t averaging 37 degrees yet.

From: Kalispell, Montana

Q: Do robins return to the same place each year and do they use the same nest?

A: They do not normally use the same nest year after year, but if they have good nesting success in a place, they very often return there. If not, they may move even within the same season.

Q: We have lots of snow on the ground. How do they eat? Can I feed them?

A: They are getting mostly fruit while snow is on the ground. They occasionally visit feeders for earthworms, mealworms, and/or fruits, but robins often don’t even notice feeders offering these because it’s not part of the normal “search pattern” robins use for finding food.

Q: How long do they feed their babies?

A: After the eggs hatch, both parents feed the young while they’re in the nest, for about 13 days. Once the babies fledge, both parents continue feeding them for a few days, until the mother has produced a new clutch of eggs. Then she spends her time in the nest incubating while the father continues to feed the fledglings another week or so, until the new eggs hatch.

From: Taunton, Massachusetts

Q: I live in Massachusetts (I'm a senior citizen) and every year on March 1st the robins arrive in my backyard. The timing is amazing. Do they have some innate timing mechanism connected to migration?

A: They respond to day length by growing restless and, when they move from place to place (which they do all winter), suddenly making those movements northward. But they follow the 37-degree isotherm, so their arrival in most places can vary by as much as a couple of weeks. You’re lucky to see them every March 1!

From: Camas, Washington

Q: Every spring we have the same robin trying to get in our window. We have named him Charlie. This has been happening for around 3 years. He bangs the window and sits on the upper window sill. There are feathers left from his wings and he is here every day. He acts like he wants to get in. This year I have sheer window treatments on that window but that does not distract Charlie. Have you heard of other robins doing this?

A. Most robins that repeatedly crash into windows are territorial males. If a male sees his reflection in the glass, he thinks it could be another male on his territory. Normally when one male robin intrudes on another's territory, he skulks around, and flies away when the actual holder of the territory approaches. Not so with a reflection!

Every time your robin gets close to the window, that robin image also comes closer. When your robin assumes an aggressive stance, rather than turning tail and flying away, the image robin assumes an equally aggressive stance, and at every level of increasing aggression in your robin, his reflection matches it. Male robins spend a lot of time and energy keeping intruders away during the time the female is nest-building and incubating eggs.

The only way you can help is to get rid of the image bird by breaking the reflection (without breaking the window). Closing a curtain from within seldom works, because birds can see very well, so even a faint image is very evident to them. Taping paper or cardboard to the outside of the window can be unsightly, and destroys the whole purpose of having a window, but is 100% effective. Soaping the window from the outside can work, but you really need to cover the entire thing.

One thing that sometimes works is to hang helium balloons from the window, tied to a two- or three-foot length of string (or longer) floating at just about the level the robin is focused on. For some reason, birds seem to fear helium balloons—I think because nothing they ever encounter in the natural world falls up so the movements seem very unpredictable. A rubber snake or plastic owl sometimes works, but birds often figure out within a day or two that they're fake. Once the baby robins hatch, your male will get so busy tending to their feeding and care that he will stop worrying about that phantom image of himself.

From: Old Saybrook, Connecticut

Q: When can we expect to see our first Robins in eastern, coastal CT?

A: Usually sometime in March, but the first big push would normally track with the 37-degree isotherm, so is highly weather-dependent.

From: Plum Borough, Pennsylvania

Q: I'm interested in making the Robin platform nesting box from the plans given but I would like to have some ideas on where I could install it in my yard. I have maple trees. What is a good direction for it to face? Thank you.

A: Most people construct nest platforms for robins on buildings, often where there’s an overhang above to protect the nest from at least some rain and wind. When nesting in trees, robins tend to choose a conifer for their first nest, so they can count on protective branches above before leaves are fully out; they move to deciduous trees later in spring and summer.

Regarding your comments, wherever birds construct their nests, there are risks. Predators may quickly learn to associate nest platforms and boxes with tasty eggs and nestlings. Babies falling out of nests over a sidewalk or patio may die from the impact. Older and more experienced parents learn about some of the hazards the hard way, and so birds are more likely to choose better nest sites and construct better nests as they get older. Robins normally tend to build their mud nests on very thick branches, where wind and rain wouldn’t be as much a concern as they are for birds who nest in thinner branches. It’s heartbreaking to witness such a sad thing, but any nest in a tree, in a platform or not, is at risk from limbs breaking in a storm. And platforms in trees can be more vulnerable to crows and jays than one the robins build themselves, which can be more easily hidden from hungry eyes.

I know of no studies that indicate that robins are more or less successful using nest platforms than the natural sites they would choose without nest platforms. But when we do have a well-placed nest platform, it’s very enjoyable to watch the family grow.

Comment: A few years ago a nest high up in a maple had the bottom break out from a lot of rain and the babies landed in the grass below, The parents were so upset and were chirping like crazy (which is how I knew something was up). This went on for some time. The birds had no idea to look on the ground for their young. The young bird was trying to chirp back but wasn't loud enough for them to hear. The whole day went by and at dusk I decided to record the baby and play it back so the parents heard it. They then started to come down lower in the branches and then found their young one. They started feeding it right away. The other one had died already. So I think the platform box would be a good thing

From: Washington

Q. We have a robin building her nest in the same location on our front porch high up on a pillar for the second year in a row. Is this likely the same
robin or her offspring?

A. This is much more likely to be the same robin pair using a familiar place where they've had success before. Young robins aren't very likely to return in spring to where they were hatched. When they migrate in spring, they may end up hundreds of miles from where they were hatched.


Q. Our robin's eggs just hatched in their nest on our front porch high up on a pillar four days ago. I heard a rustle and ran out to find a crow raiding the nest. I was a moment too late as it had a mouthful and three robins were chasing it. I am heartbroken to see nature taking its course. The mama bird came back to the deck railing twice and chirped. She guarded the nest as the crow lurked for more and I scared him off once. Yet, she has not flown back up to the nest. I figure the crow must have either taken all of her babies or that she fears returning. Now that her nest site is compromised, is she likely
to ever come back? I felt honored she felt safe here for two years and now I am sad to think it may be over. If we don't see her return, should we remove the nest and how long should we wait? Generally I try not to interfere with nature.

A. What a sad story for your robins. Crows or jays usually return to a
nest until they've removed all the nestlings, so this will probably end badly for the whole family. Robins tend to choose a new nesting spot when they lose their eggs or chicks, which is especially wise when a jay or crow raided the nest, because these intelligent birds do remember where they found food and return. Sadly for robins, crows and jays are raising their own young at the same time robins are raising their young, and they need small birds to feed their young as robins need worms. Robins seem to only half-heartedly continue caring for eggs or young once a nest is raided, perhaps understanding that the crow or jay is very likely to return. If the parent robins continue to care for the young, it's possible that one or two will
survive, but if indeed the nest fails, the robins are likely to try again in another place that the crow hasn't discovered. I hope it's in a place where you can watch again.