Tree swallow pair

Jim Williams, Special to the Star Tribune

The early birds don't get the bugs

  • Article by: VAL CUNNINGHAM
  • Contributing Writer
  • May 22, 2012 - 2:53 PM

Q I began noticing tree swallows very early in the spring, and it worried me, because I am aware that they live on insects. There weren't many bugs around so I'm wondering if the swallows found enough food to survive.

A Good observation, and I worry about very early swallows, too, because they often appear ahead of the insect bloom. Tree swallows return from their winter homes earlier than many other kinds of birds that consume flying insects. They're known as aerial insectivores, and if they can't find enough insects to eat, tree swallows have another survival strategy -- they can consume berries, even the dried-up, meager crop remaining on bushes in early spring.

Can birds control beetles?

Q Since Japanese beetles lay their eggs underground, could birds help control these destructive insects after they hatch?

A I asked Jeff Hahn from the University of Minnesota's Department of Entomology for his reaction. He notes that Japanese beetle grubs live fairly deep in the ground, from 2 to 4 inches below the surface. This would seem to put them out of reach of birds that probe into soil with their beaks, such as European starlings and Northern flickers.

So it sounds as if we can't look to birds to help control this invasive landscape pest. For helpful information, check, and then type "Japanese beetle" into the search box.

Telltale feathers

Q A screech owl occupies my wood duck house each winter, and when I go to clean it out in the spring, I invariably find red feathers piled up inside. Does the owl eat cardinals or are cardinals using the box, too?

A Interesting question, and the answer is based on the behavior of each of these species: Cardinals don't nest inside cavities so they would be very unlikely to enter your wood duck box willingly. However, songbirds are a major prey item for screech owls, so your owl is probably killing cardinals and bringing them back to the box to consume during the winter.

Something to crow about

Q I am fascinated by crows and have begun cawing to them as they perch. Now they fly around my back yard when I'm outside and reply to my calls. Is this a bad thing to do?

A Glad to hear that there are other crow fans out there, and you must be an accomplished mimic, if your neighborhood crows call back. I'm sure you're doing no harm by conversing with your back-yard crows. They're among the most curious of birds, so are probably fascinated by a human who sounds like they do.

Badly placed nest

Q Last year raccoons killed all the young robins in a nest in a low tree in my garden. This year the robins are building a nest in the same place and I want to avoid a repetition of last year.

A Raccoons like nothing better than finding a nest full of helpless young birds (the same goes for squirrels and cats). You may not be able to deter your nest-building robins but you could buy or build a robin nesting platform, essentially a shelf with three low sides, and place it under a roof eave, within sight of the current nest.

Robins nest twice a season, so it might catch their eye for their second brood. I haven't seen any kind of fencing that would keep raccoons away from the nest in the low tree, unfortunately.

Window deflectors

Q I wanted to share a trick that works for me for keeping robins from attacking my windows. I hang compact discs on fishing line, then hang them from a horizontal bar made from a wire coat hanger. Set this outside in front of a window but not so close that the CDs bang into the glass. It helps to drill a hole in a few CDs, then hang one below another, so you end up with several per hanger. A tiny breeze is enough to move the disks and spook the birds.

A This sounds like an excellent system for deterring robins, cardinals and others from attacking their reflection in a window. Many people have problems with birds repeatedly and intentionally smacking into a window in the springtime, when birds' hormones increase their aggression toward perceived competitors. This also sounds like it should help prevent birds from colliding accidentally with windows. Thanks for a great suggestion.

Bluebird behavior

Q I watched a bluebird land on a telephone wire, and then suddenly drop to the ground. I watched for five minutes and the bird didn't move, so I approached and found it sitting on the roadside with wings spread wide. Any ideas about this behavior?

A You've described the hunting style of the Eastern bluebird -- watch and then drop onto their insect prey. I'd bet that your bluebird spied a tasty-looking beetle on the ground and dropped down to eat it. Or it could be that the bluebird was sunbathing or dustbathing, both normal activities for many kinds of birds.

A third possibility is that the bluebird spied an ant colony and stationed itself over the anthill so that ants would crawl on its feathers and leave formic acid behind. This acid kills other kinds of insects that may be infesting a bird's feathers.

Food for doves

Q We seem to have mourning doves around my house all year long, even though I thought they were migrants. Is this normal and what should they be eating? I scatter cracked corn for them, and dried fruit and seeds.

A Yes, it's normal: Mourning doves are found in our area all year long. You're feeding the right foods to the doves in your back yard. These ground feeders are big fans of corn and will enjoy the fruit and seeds, as well. You might consider setting up a heated birdbath because doves are always eager for a drink. In winter, a large group of mourning doves shows up at my birdbath just before nightfall and drinks with great enthusiasm.

Eagle food

Q When I looked for the source of the fur dropping down from a tree in my neighbor's yard, I saw a bald eagle stripping the fur off a rabbit and eating the meat. Is this usual?

A It was news to me that a bald eagle would catch and eat a rabbit. But after checking several sources, I see that there are records of eagles dining on rabbits. Fish are their first choice but when fish aren't available, eagles turn to a wide variety of other foods. A rabbit out in the open in the daytime would make a good lunch for an eagle.

Salty tears

Q We spent our vacation in Alabama, on the Gulf, and I was surprised to see loons on the water. Aren't they freshwater birds?

A Turns out loons are freshwater birds in spring through fall and saltwater birds the rest of the time. Winter loons have salt glands that remove and concentrate the ocean's salt, which is then excreted through tears or nasal passages. When the birds return to inland lakes to breed and raise their young, the glands aren't needed, so they shrink until the loons reach saltwater again.


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