Canada geese often provide day care for other goose parents

Q: I was driving by our local lake recently and saw an amazing sight, one adult Canada goose and 15 little goslings. Isn’t it unusual for a goose to have this many babies?

A: Yes, it would be highly unlikely for a pair of geese to have this many youngsters. The group you saw was instead a goose nursery, sometimes called a crèche, and it’s a good strategy for keeping goslings safe while allowing their parents to take some time off. Those 15 goslings probably came from three families, since Canada geese usually have five youngsters. One or a few adults keep watch while others feed themselves or loaf somewhere nearby for an hour or two. Adults often group together for several days or weeks in these “day care” flocks. There may be 10 goslings from two families or as many as 100 from many nests. Adults watch over the youngsters communally, and their many watchful eyes provide greater protection from danger than if one set of parent geese watched only their own young. This kind of brood amalgamation is common, but not universal — some adult Canada geese merge temporarily with a group, some don’t.

Q: Robins decided to nest under our deck, but they have built two nests, and even started building a third. It appears that the female is sitting on both nests alternately, and I can confirm that at least one nest has eggs, but don’t want to disturb her on the other one. This seems pretty unusual to me, have you ever encountered this?

A: I haven’t, but checking into it I learned that it happens from time to time in the robin world. Sometimes a pair will build nest after nest and try to maintain them all. However, after the female lays eggs and begins to incubate them, she’ll spend more time on one nest than the other. There’s no way she can successfully keep two sets of eggs warm simultaneously, so the eggs in one nest won’t get as much attention and will end up not hatching.

Q: I’m confused about feeding suet during warmer weather. My woodpeckers love it but I have heard mixed opinions, some saying not to put out suet in the summer.

A: Good question, and suet can be a problem in warmer weather. We should never offer raw suet after outdoor temperatures rise above freezing: It melts and the fat can drop onto birds and impair their ability to keep their feathers clean and dry. However, rendered suet cakes don’t melt as easily but still become very soft on hot days, and some bits may get dropped on the ground as birds feed. Parent birds make good use of suet for feeding nestlings, and it saves them time that they’d have to spend hunting down insects for their chicks. But I take down my suet feeders in July and August if we’re having a hot summer.

Q: We put out grape jelly for orioles, and many kinds of other birds show up for a taste, too. But a neighbor told us that commercially made grape jelly is not good for birds, due to the high sugar content and artificial coloring. Is this true, or is this an area where “all things in moderation” might apply?

A: Good question, and I think you’re right, that grape jelly isn’t harmful if eaten in moderation. Grape jelly is much sweeter (usually through the use of high-fructose corn syrup) than natural fruit, but if orioles and others use it as a supplement to more natural foods, they should be fine. I know of people who buy only jelly made without high-fructose syrup and it would be worth the effort to track this down. Putting out jelly in small containers is best, to reduce the chances of birds falling in and getting their feathers saturated with this sticky stuff.

Laura Erickson, renowned bird writer and birder, says that she puts out only small amounts of grape jelly each day, because insects tend to fall into it and bacteria probably thrive, too. Also, some birds don’t practice moderation and gobble jelly all day long and teach their offspring to do the same, to the exclusion of foods that are better for them. There’s no getting around the fact that grape jelly isn’t a natural food. But in spring, when there is no fruit available in the natural world, many birds welcome the stuff. Erickson offers an interesting idea: How about setting out chopped grapes for birds, instead of jelly?

Q: I’m familiar with black and white woodpeckers, but now I have one of these birds coming to my feeders and it doesn’t look like a normal woodpecker. Where others have white feathers, this bird’s feathers are a light brown. Is this some kind of hybrid?

A: That’s an excellent observation, and the photo you sent shows a hairy woodpecker with tan body feathers. I see similar woodpeckers from time to time at my feeders, too. In fact, just this week, I’ve noticed a hairy woodpecker that would normally have white body feathers but instead has a buffy color all over its chest and belly. I can’t find much information about this, but it seems as if this occurs from time to time with downy and hairy woodpeckers and could be due to a gene variation that leads to the buff color. People sometimes report woodpeckers that have a dark brown wash on their backs or wings, but this seems to be due to exposure to tree tannins, and is different from the buffy wash phenomenon, which is likely due to pigment produced in the feathers.

Q: I love the fact that Baltimore orioles come back to my area every year in early May. I’m wondering if I’m seeing the same pair of birds each year — do a male and female mate for life?

A: These beautiful orange and black birds are a pleasure to see and listen to each spring. And the birds in your area might well be the same pair that nested there last year, since experts say that orioles that survive fall and spring migration will likely return to the same territory they used the previous year. However, the odds are against this happening: There’s only a 25% chance that both birds will make it through two arduous migrations, fall and spring. Generally, they mate for life, but their lifespan tends to be only one year. If only one makes it back in the spring, he or she will quickly pair up with another oriole.

Q: It makes me a bit queasy to watch robins tugging earthworms out of the lawn. How many of these does a robin need to eat in a day and how about their young in the nest?

A: An adult robin might eat 50 nightcrawlers a day, and these large worms run between 5 to 8 inches long, so these figures might be the source of a popular internet claim that robins eat 14 feet of earthworms a day. They feed their nestlings a high-protein diet made up of caterpillars (50%), earthworms (29%) and insects like ants, flies and beetles (21%). For their first four days, robins regurgitate a diet of partially digested insects and worms to their hatchlings, then gradually change to earthworms broken into small pieces and finally whole worms and insects. Young birds mature fast on such an all-protein diet and the youngster are almost the same size as their parents when they leave the nest after about two weeks.

Q: I miss my chickadees! All winter long I enjoyed their visits to the safflower feeder, but now they’ve disappeared. What happened?

A: The most likely explanation is that your chickadees are extremely busy raising their brood somewhere nearby, in a tree hole or stump. They and their nestlings are eating a diet made up almost entirely of insects and worms, and it takes a great deal of time to locate enough of these to feed up to eight chicks. They don’t spend much time at seed feeders until after their youngsters leave the nest, at which time you might see quite a few chickadees at your safflower feeder. And at your birdbath, since all birds need to drink and bathe.

Q: We have a bluebird house on our property and put a brass plate around the entrance hole to make it smaller to keep non-bluebirds out. It certainly keeps the wrens out but we’re wondering if it is frightening the bluebirds away?

A: It all comes down to the size of the entrance hole inside the metal plate. The North American Bluebird Society says bluebirds can use a 1 ½ inch round hole, or a 1 ⅜ by 2 ¼ inch vertical oval hole. If the hole inside the metal ring is now smaller than one of these dimensions, then it’s too small to permit bluebirds to enter. I suspect yours is too small, if it’s keeping wrens out, since wrens are smaller than bluebirds. I’ve seen metal rings (called excluders) at wild bird stores that are large enough to allow bluebirds to enter a nest box. You might enjoy the Bluebird Society website: nabluebirdsociety.org.

St. Paul resident Val Cunningham, who volunteers with bird organizations and writes about nature for local, regional and national newspapers and magazines, can be reached at valwrites@comcast.net.