Proliferation of cardinals a fairly recent event

By Bob Duchesne, Special to the BDN
Posted Sept. 21, 2012, at 11:26 a.m.

I admit, a column on cardinals is just shameless pandering. Who can resist reading an article on a bird so splendid? I’m often asked if northern cardinal populations are spreading in Maine. Yes, they are, and they’ve been doing so for a long time. Though there are probably many factors in the northward movement, the suburbanization of America and the proliferation of bird feeders probably have a lot to do with it.

Originally, cardinals were limited to the southeastern United States. About a century ago, they started to expand their range along the Mississippi River and its tributaries. Before that, they were seldom seen north of the Ohio River. By 1895, cardinals had reached the Great Lakes, and they spread into southern Ontario by 1910.

One of America’s earliest field guides asserted in 1903 that southern New York was as far as they had spread to the northeast. The first cardinal to be found nesting in Connecticut occurred in 1943, and by 1958 the species was discovered nesting in Massachusetts. It has now stretched its limits into maritime Canada. It is so widespread that it is the official bird of seven states — the most for any species.

It is the name of two major league sports teams and the mascot for at least a dozen colleges.

I recall seeing my first in Brunswick in 1978. Though I had not seen them here before, the whistled “chew, chew, chew” was unmistakable. Both sexes vocalize. In mating season, females whistle back at singing males. Cardinals are prolific parents, raising up to four clutches a year where conditions are ideal. Across the South, cardinals are forest birds that can be found anywhere there is sufficient brushy cover. In Maine, they are typically birds of the suburbs. They are easily attracted to platform bird feeders and they nest in ornamental hedges. Cardinals will shift their range as winter dictates, but they are generally nonmigratory. Their wings are relatively short, which is typical of nonmigrants.

In summer, insects compose up to one-third of a cardinal’s diet. In winter, vegetative matter is 90 percent of their food supply, mostly hard-shelled seeds. Their heavy bills can cleave the hardest seeds with no difficulty. And to make it easier, their beaks have a special adaptation. The edges of the lower bill fit into grooves in the upper mandible, and the cardinal uses its tongue to maneuver the seed into this vise.

The distinctive crest reminded American colonists of the ceremonial headdress worn by European bishops and cardinals: hence the name. In the nin19th century, cardinals were often trapped in the South and sold in the North as popular cage birds. Many thousands were shipped to Europe. That practice ended abruptly with passage of the Migratory Bird Treaty Act of 1918.

Cardinals are odd in other ways. Brightly colored birds generally migrate toward the tropics in winter. In an equatorial land of year-round flowers, bright colors are the norm. Vivid hues aren’t as noticeable to predators and, in fact, brilliant colors are sometimes a warning to stay away. But what chance does a red bird have of escaping notice against a backdrop of white snow? Cardinals don’t even have the good sense to molt into a dull winter plumage as so many birds do. Expect them to stay near bushes and cover in winter in case a quick escape is necessary.

When agitated, cardinals raise their crests to higher prominence. The crest is unusual, but certainly not rare. Blue jays and titmice have them, too. You can always assume that peculiar features of birds have something to do with attracting a mate or defending a territory. For instance, romantically inclined hooded mergansers raise their crests mostly in breeding season. For some species, such as kinglets, the colored crest is lowered and not visible except when raised as a sign of aggression toward competitors. For birds with permanently raised crests, expect it to be swept backwards for streamlined flying.

Since cardinals are nonmigratory, they are usually monogamous and mate for life, and males will care for females while they are nesting. They are aggressive about defending their territories and are particularly noted for attacking their reflections in windows and mirrors. They also will defend a favorite bird feeder from other cardinals. Cardinals molt at the end of nesting season, so perhaps you’ve seen a few unattractive ones lately.

The species remains a backyard favorite. If you want to impress children, show them one of these.

That’s my cardinal rule.

Bob Duchesne serves in the Maine Legislature, is president of the Penobscot Valley Chapter of Maine Audubon, created the Maine Birding Trail and is the author of the trail guidebook of the same name. He can be reached at duchesne@midmaine.com.

 

http://bangordailynews.com/2012/09/21/outdoors/proliferation-of-cardinals-a-fairly-recent-event/ printed on September 23, 2014