From: NORTH CAROLINA
Q. How do you tell a robin's age?
A. Baby robins that hatch this year will have spotted breasts. When they are just a few weeks old, they will also have a very short tail, but when the tail feathers reach full length, the young birds will look pretty similar. They begin molting into their first "adult" plumage during summer, and then look like adults. Bird banders and ornithologists can often still recognize the young of the year because their plumage looks a bit paler and browner, and the white spots in the tail are smaller. By the time birds are a bit over a year old, they can't be aged anymore-we just call them "adults." Sometimes very old individuals develop whitish spots around the face or in other places on their bodies, but these white areas can develop from other causes, too, and sometimes birds are born "partial albinos" that have white areas on their bodies their whole lives, so this isn't really helpful in figuring out how old a bird is. We've tried asking, but the birds just won't tell us!
Of course, scientists have one very accurate way of telling how old some individual birds are: they put a numbered band on one leg of birds they've trapped in special nets called mist nets, or on one leg of nestlings. These numbers are impossible to read unless the bird is in the hand, so sometimes when scientists study specific populations of robins, they add colored leg bands so they can recognize individual birds. When birds are found dead or caught again, or when a bird with a colored leg-band is seen, scientists know how long that individual bird has survived since banding-when it was banded as a nestling, they know exactly how old it is. This is how scientists aged the oldest robin we know about--it was 13 years and 11 months old.
Q. Why do robins stay about 10-15 feet away from each other when eating?
A. Robins, like most birds, are territorial, and even during their period of flocking during migration and winter they feel most comfortable maintaining a certain amount of space around their bodies. Birds usually space themselves naturally, but occasionally one comes closer to another than that other bird likes--then sometimes they fly at each other aggressively to get the other bird to back off a bit.
Q. Is this year's migration population more or less than the average?
A. It's hard to say, because robins spend the winter in so many places that when numbers are low in one place they may still be very high in another. In some cities and towns, robin numbers are declining because of problems such as lawn pesticide use, house cats, and increasing crow numbers, but overall, based on Breeding Bird Surveys and other long-term studies, we know that robins are doing very well, and their population has been stable to increasing since DDT was banned in the early 1970s.
Q. One of my first graders wants to know what color nectar is?
A. Nectar is clear, and usually colorless. That is why it's unnecessary to add food coloring to sugar water you're setting out for hummingbirds and orioles. The coloring doesn't add any value to the food, and may be bad for them.
Did you know that there are several different kinds of sugar? Sucrose is the kind we humans use, and the kind we put into our hummingbird and oriole nectar. Robins are fond of sweet things, but NEVER drink the nectar from these feeders because they probably have an aversion to (that means they just don't like) sucrose--this is because their bodies can't even digest it. Sugars that they prefer are fructose and glucose--two sugars found more regularly in the fruits that robins eat.
Q. Is it always clear? Does it change colors?
A. Usually when natural things have a color, there is a reason. There is no natural color to nectar, and because it stays hidden in flowers (which are colored to attract the animals that pollinate them), there isn't a reason for nectar to have a color or to change colors. When it gets cloudy, that is because fungus or bacteria is growing on the sugar.
Memorial Elementary School
Q. How do Robins find worms?
A. Robins almost definitely find their worms by seeing them in their burrows. They cock their heads to improve their ability to look at the ground. Some robins find worms the EASY way-they learn that worms emerge from burrows after rain, and can be really easy to pick up on sidewalks then.
Q. Do they see, smell or feel them in the ground?
A. A scientist named Frank Heppner conducted a study that established that vibrations, odors, and sounds do NOT help robins find worms. They see them inside their burrows or wiggling on the ground.
Knoxville Alternative Homeschool Group
Q. We have a robin nesting on our deck in a high traffic area. They don't seem to mind that their nest is 2 inches away from the latch on our gate. I put a board up to give them more privacy...my question is will they harm my young children going up and down our stairs once eggs are involved?
A. It's hard to predict animal behavior, but if robins are accustomed to children as they build their nest, they aren't usually concerned about them when the eggs are laid and after they hatch. Normally the worst that will happen is that when you or the children walk past, they flush out of their nest and stay away for a while. But a very few robins are unusually aggressive in defending their territory, especially after the eggs are hatched. Normally when robins "attack" people, they go for the back of the head. If your pair does become extremely territorial, they won't hurt your children but could easily frighten them.
Q. I read that they will seek a new nest around June. Why aren't they bothered by our presence? It is a new neighborhood and my guess is that we have ruined their ideal nests sights and this is what they chose. The Jacksons
A. A robin's ideal nest sites are often right on a window ledge or a porch light on a house, so the new neighborhood may be just what the robins wanted! Although some robins do live in deep woods, most of them prefer areas with open lawns and ornamental fruit trees. Many bird species decline with development, but robins seem to thrive on it when they don't have problems with lawn pesticides, cats, and crows.
Journey North Science Writer