Robins get a ‘jump’ on invasive worms

Q: Do robins eat jumping worms? I’m hoping they do.

A: Sounds like you are having problems with these invasive worms that alter the soil and create big problems in forests. There are conflicting opinions online, so I contacted University of Minnesota Extension, always a good source for gardening questions. Yes, robins do eat the alien worms, is the reply from Angela Gupta, a professor and educator for Extension. She managed a project that studied the worms for two years, and said volunteers in the project reported an increase in the numbers of toads, frogs and robins in their study areas, indicating an increase in the worms. Other animals, including wild turkeys, raccoons and opossums, also ate the worms. One volunteer noted that she was alerted to new hatches of the worms by an increase in robins feeding in her yard. Gupta herself has observed robins eating jumping worms in her own gardens. So yes, robins do eat them, but there are probably more worms than robins can keep up with in a landscape. These invasive invertebrates reached our area via mulch and potted plants.

Q: I haven’t seen many hummingbirds lately, but my nectar feeder is being emptied frequently, in about two days. And then last night my rain gauge next to the feeder was snapped off. Who or what is doing this, could it be raccoons?

A: It certainly sounds like raccoons are the culprits — they’re good at standing on their hind legs and tipping nectar feeders so they can slurp up the fluid. You could try bringing in your feeders in the evening, then putting them out just at sunrise, to give hummingbirds a good boost of energy to start the day.

Q: A pair of swans spent the summer on a lake in my suburban community. Is finding them in this kind of location unusual?

A: Trumpeter swans used to be a rare sight but their population is now on the upswing and they can be seen on many lakes around the metro area. I’m assuming that the swans you observed in August had no cygnets, and would guess that their nest failed, maybe due to the major rainstorms in the spring washing out their nest, eggs and all. It’s also possible that a predator snatched their eggs. A third possibility: These might have been birds that formed a pair bond before they were old enough to breed.

Q: Green herons nested in a white pine in our front yard. There are four young birds and they have been buzzing close by my wife and me when we are outside. Then they fly to a nearby perch and watch us. What’s this about? They seem as if they want to get our attention.

A: What fun to have a family of green herons nesting nearby. I’m sure these young herons mean you no harm; they’re probably just curious and approaching you to see what’s up. Young animals often are intrigued by any activity, since everything is new to them, and they need to learn about this new world they’re entering. And frankly, youngsters have periods with not much to do, so any diversion is welcome. I’d enjoy them while you can, because they’ll migrate away in the fall.

Q: This is the second year I’ve noticed several of the blue jays at my feeders that are missing the feathers on their heads. They look so strange and I worry that they’re ill and maybe will pass the illness to other birds.

A: Bald birds are a disconcerting sight, but they’re not sick, they’re just undergoing a brief bald period after all their head feathers fall out. This condition is reported most often in cardinals, blue jays and robins. These bald birds suggest birds’ dinosaur ancestors to some people. Experts don’t agree on its cause, some attributing such baldness to a gene-dictated very fast molt, while others feel feather mites might be the cause. I tend to align with the “fast molt” camp and agree with a blogger who used the term “blue vultures” to describe bald blue jays. New head feathers grow out in a few weeks and the birds are ready for the winter season.

Q: I enjoy the catbirds in my yard all summer long and miss them when they leave. Can you tell me where they spend the winter?

A: I feel the same, as my backyard is enlivened by the presence of these fruit-loving birds. They spend the late summer gorging on elderberries and dogwood berries, then they head southward. Catbirds from our area tend to spend the winter in Central America, and I remember the thrill of seeing what might have been “our” birds in Panama and Belize. Many others spend winter along the Gulf Coast and into Florida. Their rich warbling songs, interspersed with sounds they mimic, is easily recognizable. Watch for catbirds to return next April, possibly even the same bird that spent this summer in your backyard.

Q: Do male and female birds that formed a pair to raise young migrate together in the fall?

A: Generally not, says the Audubon Society. Male songbirds often depart before females and pairs do not stay paired up.

St. Paul resident Val Cunningham, a member of the St. Paul Bird Alliance (formerly Audubon Society), writes about nature for various publications. She can be reached at valwrites@comcast.net.