From grape jelly to high-protein insects, orioles' diet changes with the seasons

Q: I love to see the orioles at my grape jelly feeder each spring, but wonder why they disappear in late May? What can I do to keep them around?

A: It's not that you're doing anything wrong with your oriole feeding system, it's just that their needs change as breeding season arrives. Those early Baltimore orioles were happy to gulp down your grape jelly, but now that they're feeding youngsters in the nest, they need high-protein insects for their young. This diet speeds up nestling development and lets them grow to the size of their parents in less than two weeks.

The orioles may return in July, as parent birds teach their brood to feed themselves. Experts now warn that the high concentration of sugar in grape jelly isn't healthy for birds, so they advise setting out only small containers of jelly at a time, maybe in a jar lid, so the birds don't pig out.

Q: I had an odd experience around 11 at night in early April. At first, I heard owls hooting, but then this changed to very loud noises that sounded like jungle birds or monkeys, and it seemed like there were more than two owls. This went on, off and on, for an hour. What was this all about, and were these great horned owls?

A: It's much more likely that these were barred owls engaging in courtship calls. An article on Audubon's website refers to this species' siren calls, wails and "wonderfully entertaining monkey call."

Karla Bloem at the International Owl Center in Houston, Minn., notes that barred owls are famous for making these loud calls and shrieks. Barred owls put on a similar performance in the night woods near a cabin where I was staying outside Duluth some years ago, and I agree, it's eerie.

Q: My neighbor has put up a very loud wind chime and I'm worried it's going to frighten birds away from my feeders.

If wind chimes worked to deter birds over the long term, all sorts of businesses that want to keep birds away would put them up.

Q: Crows are bringing gross things to my birdbath. Last year it was dead frogs, but I can't even tell what it was last week. What are they doing, are they washing their food?

A: Crows can leave a disgusting mess in a backyard birdbath, as I've found on occasion. They do this to soften up dry food, such as stale bread pieces, and/or to soften and add moisture to food they're bringing to their nestlings. There probably is an active crow nest in your neighborhood and parent birds may be immersing scavenged food items (and leaving bits behind) to make them easier to go down their youngsters' gullets.

Q: A group of bald eagles began showing up at the local lake, two of them adults and the rest young birds. The adults would sit in a tree and occasionally fly down to the water, with the juveniles following, all of them swooping and swerving. I'm wondering if the adults were training the young eagles in how to fish. Could these be their offspring from past years?

A: "Eagles are scavengers more than hunters," says John Moriarty, senior manager of wildlife at Three Rivers Park District, and a longtime observer of eagles. He surmised that the young eagles in this situation were attempting to steal fish caught by the adults or watching for food scraps to be dropped by them. If any instruction in fish-catching was taking place, it was inadvertent, he added.

Q: I read a news story that claimed that a single Canada goose could produce up to 4 pounds of droppings a day. No wonder they have such a bad reputation, if this is true. And do they poop while flying?

A: I read that same claim and wanted to find the source, which appears to be a wildlife management company, which would have a commercial interest in estimating on the high side. As often happens on the internet, many sites now use this same figure, without citing a source. In doing some research, I found one expert who estimates a Canada goose could produce a pound or more of droppings in a day, which seems more believable. Since Canada geese enjoy the grassy habitats we provide, on golf courses, lakefronts and parks, and tend to congregate in groups, they can leave a messy poop load on grass and paths.

It's unlikely that a goose would poop on you while flying overhead, since they tend to relieve themselves just before or at takeoff. And they generally avoid taking off in the direction of humans.

Q: How far do birds migrate in a day?

A: As you can imagine, this varies a great deal, depending on the species, season, weather conditions and availability of food along their migratory route. Migratory birds are in a hurry to claim nesting territories in the spring, but not so rushed in the fall, after breeding season is over. If they encounter storms along the way, birds may remain in an area until the weather improves (or fly ahead of a storm to avoid it). And if food is abundant at a stopover site, birds may linger to consume calories to provide more fuel for the flights ahead. Some songbirds have been found to travel 30 to 50 miles each night, while others make journeys of up to 200 miles per night.

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