There are exceptions to all birds being equal in my book. And one of them is the lazy brown-headed cowbird female, who neither makes a nest nor raises her young. It is not her fault for being lazy, and do not blame Mother Nature.
For centuries, if not millennia, the cowbird followed the always-on-the-move American bison, also known simply as the buffalo — and this did not give the birds time to mate, build a nest and raise their young. So, somewhere in its history, it began giving up the time-consuming aspect of breeding by not bothering nest building and settled for dropping an egg here and there in available nests already built by another bird ready to incubate and raise its young.
Or it could have been the other way around; it was already a parasitic egg-laying species that encountered the bison, and by following the herds thousands of years ago that occupied grasslands from Alaska to the Gulf of Mexico, found a new insect food source.
The many millions of bison nearly became extinct in the late 1800s because of commercial hunting and wholesale slaughter (said to reduce the Native American population); another cause was diseases from domestic cattle. Their near-extinction dramatically reduced the insect food source for the cowbird, causing them to spread eastward in the 1800s for farming as forests were cleared for agriculture, homes, industry and energy.
I became suspicious of the cowbirds in our yard ,when I noticed them staying beyond the usual passing through, when I kept hearing the male singing to a female or two and visiting our birdbath. Then, on two separate days, I found robin eggs beside the arborvitae bushes and on the deck. There is a robin nest close by, and while not a guarantee, often a female cowbird will toss out an egg to make room for her egg. Also, I know of two chipping sparrow nests in our neighborhood, as well as a cardinal’s and a mourning dove.
I read somewhere that cowbirds are known to parasitize about 200 species of birds, although not all birds put up with the intrusion and don’t make suitable foster parents.
Q and A: Sometimes posted queries get misplaced either because of the post office or the cluttered condition of my desk. Regardless of which, I have a question from Janice S., of Cheshire, asking why she has not seen any juncos this year, even though we had plenty of snow. And usually we see lots of them enjoying the snow.
Dark-eyed junco, formerly known as the slate-colored junco, is a typical winter species in the valley, and why they missed your yard this past year is a mystery. You didn't mention having feeders, and if not, it might well be others in your neighborhood have provided a reason why this enjoyable species has discovered an excuse for spending time elsewhere. I am sure that it is not personal. Reports from other readers have not mentioned a lack for this species, and our yard and feeders' yards had their share.
Q: We have an old tree in our yard. Not sure of its name, some kind of maple, I think. It has to come down and has a little chickadee nesting in it. When will be the safe time to schedule its removal? And can I make a box that will replace the tree? If so, do you have dimensions?
A: To be on the safe side, I suggest the third week of July or later to have the tree removed.
According to René Laubach (retired director of Berkshire Wildlife Sanctuaries) and Christyna M. Laubach (retired science teacher and department head), authors of "The Backyard Birdhouse Book," 1998, Storey Books:
"Floor dimensions 4-inch, diameter of hole 1 1/8 inch diameter, box depth below hole six inches. Mount 4 1/2 to 15 feet above the ground. Box material wood and place about one inch of wood chips in the bottom of the box. Clean box after each use."
I know the answer, but wonder if your readers know the answer. What is the most serious mistake many gardeners make when feeding hummingbirds?
— Phillip, Pittsfield