Help from the Robin Expert
Contributed by Ornithologist Laura Erickson
- windows and houses
- wintering robins
Q. Can I move and relocate a robin’s nest?
A. Unfortunately, no. If you move a robin’s nest the parents will most likely abandon the nest, eggs, and young. Nest-site fidelity grows during the nesting season. The more time and energy the birds invest in the nest, the less likely they are to abandon it when disturbed. However, actually moving the nest is not merely a disturbance—it makes the entire nest environment different. The birds’ fidelity is to the whole nest setting
Q. After the baby robins leave the nest, should I leave it for her to use again, or take it down?
A. While robins might repair or build on top of a previous nest, most of them build a new nest. This is best for many reasons. A used nest is a mess, stretched out and often home to insects or parasites and possibly poop. Take the nest down and the site will be ready for the next robin.
Q. Will the male robin take over the nest if the mother cannot?
A. If the female was killed, the eggs are doomed. The male doesn’t have a brood patch and doesn’t know how to brood eggs. If it was the male who died, the female might continue to incubate, but may just give the nest up for lost because the chances of bringing off more than one or two nestlings is very slight with just her to feed them. Also, the female starts focusing on a new batch of eggs after the young fledge, so the father is quite essential for the ‘finishing school’ lessons on surviving.
Q. Is it common for a robin to build more than one nest at a time?
A. This is a question we hadn’t been asked before, so we wrote to Len Eiserer, the author of The American Robin: A Backyard Institution. Len answered,
Building multiple nests simultaneously happens every now and again with robins. One started 26 different nests on roof rafters of a garage under construction; another built 8 on successive steps of a fire escape. Support from underneath is the primary site selection factor for the female robin — it’s more important than concealment. Because some human structures provide repetitive sites with strong support, the female can get seduced into building multiple nests.
This is an example of “supernormal stimuli” — artificial stimuli that are even more effective than those provided by Mother Nature (tree limbs). Animals have a hard time resisting supernormal stimuli. There are many examples. Your robin will probably settle on one site and just lay eggs in that nest, or else just incubate eggs in that nest after laying, say, one egg in one nest and two in the other. She won’t lay two complete sets of eggs and try to incubate both of them at the same time.
Q. Will a blue jay steal eggs from a robin’s nest?
A. The main predators of robin eggs are snakes, squirrels, blue jays, and crows. Deer eat a lot of bird eggs and nestlings, too, but only from ground nests.
Q. What can we do with the robin egg we found in our yard?
A. The best thing to do with an egg that you find is to simply leave it be. I know you’re concerned about the little baby growing in it, but there is a strong chance that there may not even be a baby in there. This may be an egg that wasn’t fertilized, or didn’t develop properly. After the other babies are a day or two old, the parents get rid of unhatched eggs just in case one of the growing babies accidentally crushes it. Rotten eggs are no fun!
Even if the egg were perfectly healthy, the chance of a human successfully incubating the egg and then successfully raising the baby from a hatchling is VERY remote. Robin eggs require high humidity, gentle daily turning, and level heat. You’d need a high-quality incubator to do it properly. Then once the babies hatch, parent robins feed them regurgitated worms and insects for the first three or four days—something humans just can’t do!. Newly hatched robins are weak and helpless, and their parents are designed precisely and have the exact right instincts for taking care of them. Our human hands are clumsy, and we have too many other concerns in our daily lives to devote every waking moment to a baby robin, as its real parents would do naturally.
There are very good reasons why it is against state and federal laws in the US to raise wild baby birds. Death at the hands of well-meaning people who aren’t feeding a robin nestling the proper diet can be painful for the baby. Far, far better to just allow the egg to cool. If a baby is still alive in there, it will simply stop developing within the egg, before it develops any awareness of pain.
Q. How long does it usually take a robin to build a nest?
A. It takes two to six days for robins to build their nest.
Q. Does the female robin live someplace separate from the nest she is building?
A. Remember that the nest is not a bed; it’s an incubator and baby cradle, so the robin isn’t supposed to be on the nest at night until she has a full clutch of eggs. Until then, she roosts on a branch.
Q. Should we try to raise abandoned eggs ourselves?
A. Robins only abandon their eggs when something happens that tells the robins they will have a poor chance of success. It seems unlikely that humans will have greater success. I know how sad it is to see these beautiful eggs and how very tempting it is to want to save the tiny babies inside. But it’s just as heartbreaking to watch the babies start out healthy, with their egg sac to provide some nutrition for a couple of days, and then wither and die at our hands.
Q. My robin built a nest and then disappeared before laying eggs. What happened?
A. Here are some possibilities to explain why the robins have not come back to use the nest:
- Something dire happened to one or both robins: hit by a car, taken by a predator, etc.
- She laid an egg but then something came and got the egg, and she quit laying.
- She discovered a potential predator, such as a cat, jay, chipmunk, or snake, eyeing her nest and abandoned it because it wasn’t a safe place to raise babies.
- She built her nest more quickly than expected (perhaps there was a a good supply of mud from a recent rain?) and she wasn’t quite ready to start laying eggs.
If she does not return after 2-4 days, go ahead and remove the nest. Any other robins that come will build their own nest.
Q. How do we know if the bird inside a robin egg found on the ground is thriving?
A. You are going to be for serious heartbreak. If a robin egg is on the ground, it was either infertile and dumped by the parents, and won’t hatch—or was carried off by a jay or crow, and the robin parents chased them and forced the thief to drop the egg. The shaking and dropping could have badly damaged the embryo, and if the egg did hatch, the baby would not be likely to survive long.
Even if the egg were healthy, most of us just don’t see all the work that goes into incubation. the right temperature is important, but so is humidity, and so is frequent turning to ensure that no part of the growing chick gets dried out or stuck to the shell. Then if it doe survive to hatch, keeping this tiny chick alive is very, very difficult to do successfully, even by a trained wildlife rehabilitator. These are some of the reasons it is against state and federal laws to keep any wild bird egg or chick.
Q. What should I do if I find an injured bird or abandoned baby robin?
A. It is against state and federal laws in the United States to possess any wild native American bird in captivity. Raising a wild bird is only legally entrusted to licensed rehabilitators. It is impossible to save every injured or abandoned bird. The most important thing to remember is to get it to a licensed rehabilitation center as soon as possible.
Q. When a nestling falls from the nest, can I put it back? Can I handle them with gloves?
A. Robins identify their babies the way we humans recognize ours-by sight and sound, not by smell. So if you can safely put the babies back in the nest, go ahead!
Q. Why has the mother stopped sitting on the nest at night?
A. By the time the babies are about a week old, the nest is getting crowded, and the babies are capable of keeping themselves warm, all snuggled together. At this point the mother robin starts sleeping on a tree branch again. If she is a wary mother, you might not see her feeding the young because robins are so fearful of alerting predators that they simply don’t go near the nest if they notice anyone observing them.
Q. My male robin was killed. Will the female find another mate?
A. During the time that robins are establishing territories, many individuals are still migrating. If they find an open territory en route, they often take it over. Also in most healthy bird populations, there are “extra” birds called floaters that wait in the wings for a territory to open up. Floaters in your neighborhood might be timid about entering the yard for a while, if your robin taught them that he was going to attack if they crossed his boundaries. It will take a little time for them to relax and check it out. Meanwhile, robins passing through may well notice an opening and fly right in. Normally females chase other females out, but fairly quickly adapt to a strange male.
Q. How can I prevent a robin from crashing into my window?
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.
Q. How do I get rid of nesting robins without hurting them or the eggs?
A. There is really no way to get rid of them without hurting them or the eggs. During this awkward time, you need to figure out how to use the backyard without stressing the robins, leading to attacks. They are at their worst just before the eggs hatch—once the babies are being fed, they usually spend so much time finding food for them and protecting them from real predators that they don’t have time to attack people.
Birds defending their nests virtually always attack the highest part of their perceived enemy. Whenever you walk past, hold a broom, balloon, or pole so it is well above your head. DON’T strike the bird with it! Just hold it vertically, and if the bird is exceptionally aggressive and does approach close enough to hit, it will hit that instead of you or your children. One other strategy I’ve heard a couple of people use successfully is to get someone else to tie up a LEASHED cat near the nest site and leave. As soon as the robins start making agitated sounds and dive-bombing the cat, go in and “rescue” them by getting the cat and bringing it in. They may well remember this kindness.
Q. What do robins wintering in the north eat?
A. Robins switch diets in fall. They turn from earthworms to berries and other fruits. Because some forms of fruit (such as mountain ash berries and crab apples) remain available all winter long even in the north, a few robins can stay in an area with food enough to support them all winter. These robins are most often found in areas where there is a bit of open water from a nearby spring, stream, river, or large lake, and where there are fruit trees. The water and fruit get them through the season.
Q. Why does a robin stay during winter? Doesn’t it know to migrate south?
A. Robins are a migratory species, but their migration is far more complicated than simply a shift southward. There seems to be a great deal of individual variation in where they spend the winter, though males are far more likely to remain in the north than females. There are good reasons. Come spring, the male’s main job is to find and defend a territory. The females’ main job is to create and lay the eggs. This requires a lot of good nutrition and food energy, so females go where they are sure of good food supplies in winter. Yes, they have to use up food energy to migrate north. But migrating and laying eggs are easier for well-nourished birds.
Q. Won’t the cold hurt robins?
A. Cold temperatures don’t hurt most birds—as long as they have food. As nights grow cooler during fall, northern birds start growing more down feathers close to their bodies. These feathers work like a down jacket. The down feathers insulate the birds, keeping the heat of their bodies inside. The robins make their body heat by shivering; as long as they have food to give them energy, they can survive extreme cold.
Q. Should I be feeding a robin wintering in my backyard?
A. Robins only spend the winter in areas where there is food available, so feeding them isn’t necessary. Nevertheless, a lot of people enjoy offering them food, creating a special bond with this pleasant bird. Robins will NOT take birdseed. Sometimes they’ll take frozen fruit, though it’s often hard to teach them that fruit in a feeder is food! Robins learn at an early age that fruit grows on trees and shrubs. They simply do not expect to find it anywhere else. One of the best kinds of food for wintering robins—and the easiest for them to discover—is mealworms. You can put out a dozen mealworms on a sunny day when the temperature is above freezing, and nearby robins will often notice their wiggly movements and investigate. Once robins discover the mealworms, they’ll come back even when the temperature is below freezing and the mealworms are stiff. If you start offering fruit in the same spot, the robins are more likely to notice it. Some favorite foods are blueberries, raspberries, and strawberries. Buy bags of frozen fruit for them, since it will freeze outside anyway!
One of Journey North’s correspondents from Wisconsin used a heated bird bath to keep mealworms thawed and moving. He thought this would allow him to feed his whole flock of wintering robins, but one of the robins took over and defended the bird bath food source against all the other robins in his yard. This arrangement still helped the other robins, who were sharing the fruit on neighborhood trees, because now there was one fewer bird to share with, and it made the one particular robin VERY happy!
Q. Do robins need water in the winter?
A. In northern climates where ponds, rivers, streams and lakes freeze over in the winter, a bird’s most available water source is often snow. But it takes energy to melt snow. Birds needs to drink and, if possible, bathe even in the winter. Dirty feathers lose much of their insulating properties, so a clean bird is a warm bird. If you have a heated birdbath and worry about birds bathing and then being unable to fly off in sub-zero weather when the water freezes on them, you can modify the birdbath to allow them to drink but not bathe. Cover the top of your birdbath with a piece of plastic-coated quarter- or half-inch hardware cloth or lace twigs or small branches across the top. Either method will allow the birds to stay dry while they drink through the openings.
Q. Why are we seeing dozens and hundreds of robins this winter?
A. The robins have likely dropped in because they discovered a rich food source.
Q. How do robins prepare for winter?
A. In October they start seriously adding down feathers to improve their insulation for winter. Also, summer food supplies have diminished; there are still plenty of berries around to eat, but robins get seriously on the move in search of plentiful food supplies for the coming winter. They start seriously moving in October. Back on October 1, 1988, birdwatchers counted over 60,000 robins migrating over Duluth in northern Minnesota, so that’s serious migration. But in fall and winter, robins don’t stay in a single spot for long — they wander about searching for new sources of still-fresh fruits.
Q. How do scientists learn where robins from one state/province migrate for the winter?
A. Scientists study bird banding data to learn where robins go. They put thousands of numbered bands on robin legs, but they know they will only recover data from a few of these birds in the future. So it takes a long time to amass enough data for them to draw accurate conclusions. Meanwhile, robins can change some of their migration patterns, making the research even more complicated. To see the U.S. Fish and Wildlife Service’s robin banding data to learn where robins from your area go in the winter, see our Bird Banding Data Study.
Q. What can I do to help robins in autumn and winter?
A. You can make your backyard bird-friendly. That means don’t rake too much. Dead leaves left under trees and shrubs are ideal spots for birds to forage for insects as weather gets colder. You can also provide cover. Birds need shelter from harsh conditions, and vegetation in your yard will help provide it. Don’t prune back dead vegetation like vines and stalks, as these provide both valuable winter cover and nesting material for birds in the spring. If you have berry bushes or fruit trees, don’t pick them bare because those fruits are food sources for robins migrating through, or overwintering in your area. The best thing you can do is to plant native fruit trees and shrubs that will provide robins with fresh, wild food. To feed them in winter, one Journey North friend set out fruit and mealworms in a heated birdbath filled with sphagnum moss rather than water.
Q. Can you tell a migrant just by its size or color?
A. Although different populations of robins are slightly different sizes and the color intensity of the plumage varies somewhat geographically, robins don’t really show the cut-and-dried plumage variations that populations and subspecies of others birds do. On average, robins are smallest in the warm, humid southeastern US, and smaller than average along the humid coast of northern California and the Pacific Northwest. Robins are largest in the high, dry Rocky Mountains, northern Great Plains, and northern deserts of the West.
Robin plumage is darkest in birds in the Pacific Northwest and in Newfoundland—both places where the humidity is exceptionally high. The amount of white in the tail is largest in the East and smallest in the West. An isolated robin population in the Baja California Sur is exceptionally pale.
But robins live up to their scientific name, Turdus migratorius (the “migratig thrush”), wandering widely and unpredictably in winter and often ending up in spring in entirely different areas from where they were raised, so there’s a lot of mixing. That means that size and color differences among populations are subtle at best; even with perfect views, we can never be absolutely certain where robins came from by either size or plumage.
Q. Why don’t birds sleep in their old nests in the wintertime?
A. Nests are nurseries, not homes. Even if they were not, the nests that served robin families so well in the summer are built to last a single season and aren’t in the best shape by now. Most nests were built on branches of deciduous trees and shrubs, and autumn’s leaf fall exposes those nests to both elements and predators. But one creature that appreciates an empy bird nest is the deer mouse. These tiny mammals will build a roof over an old cup nest and stay warm all winter!
Q. Is there enough food for wintering robins birds that do not migrate?
A. Worms have much more protein than berries. But some birds manage to achieve a “balanced diet” over an annual cycle rather than day by day. Robins require protein especially when females are producing eggs and when both sexes are molting-these activities occur only during the time of year when they’re eating worms and insects. During winter when they switch to a diet of fruits, they are getting plenty of vitamins, and the carbohydrates give them plenty of energy to sustain their bodies. Winter is the time when their activity is limited and they aren’t growing new plumage or producing young.
Regarding berries, there are many different species, and some have a bitter taste until winter. So some berries are avoided during late summer and fall, and these are the ones that remain for winter food. Robins also eat crab apples. There is clearly not enough fruit to sustain as many robins in winter as live in New Hampshire in summer, but there is enough fruit to maintain a small but robust winter population. And robins aren’t like some birds, especially neotropical migrants, that maintain winter territories. When one food source becomes depleted in winter, a robin flock will move to another place. The only time robins are sedentary, remaining in one fixed place for weeks at a time, is during the nesting season when they are in their territories.
Q. I saw a robin eating suet, which was strange to see. Is this normal?
A. It’s not unheard of, but is unusual. A robin’s warm-season diet is full of high-protein insects and worms. Suet is another source of protein. The robin you saw seems quite smart, as he’s taught himself a new feeding strategy by watching other birds at your feeder!
Q. What are good trees we can plant that provide food for robins?
A. Choose species native to North America. Some summer berry trees include:
- Red mulberry
- Wild plum
- Pin cherry
Fall berries include: Dogwood
- Mountain ash
Winter berries include: Bittersweet
- Red cedar
- Highbush cranberry
Q. Is it possible that I heard a robin in England?
A. You didn’t hear an American Robin. What you saw was a European Blackbird. Remember the nursery rhyme, four-and-twenty were baked in a pie? Those are the birds! Yes, they are very closely related to our robin—actually in the same genus. Meanwhile, the Robin Red-breast of England isn’t at all related to our robin. Homesick Europeans who settled in America named our birds for the ones they missed at home. Our American Robin is bigger and duller than theirs, but is the closest they could find to fit the bill, so to speak.
Q. How can we help robins?
A. Keep cats indoors, set out nest platforms for robins, stop using insecticides in lawn sprays and only spot spray weed killers rather than spraying the entire lawn. Plant the kinds of berry trees and bushes that provide abundant food for robins and the kinds of trees and shrubs that provide good cover for nesting. Set out bird baths and set out robin feeders.
Q. How can we make a robin feeder?
A. Robins don’t visit bird feeders for seed, because they just don’t eat seeds. But some robins do learn to visit feeders to take berries, chopped up apples, and mealworms. You can also offer mealworms in plastic dishes or acrylic window feeders.