Blane Klemek column: Rock doves are common feral birds
There was a time in my life that I lived and worked in downtown Chicago.
European starlings, house sparrows and pigeons were the most widespread city-dwelling birds that I encountered, but other common songbirds were also plentiful, especially throughout the residential neighborhoods, suburbs and the city's surprisingly diverse and numerous nature preserves.
No bird, however, was more ever-present than the "rock dove," better known as the pigeon. Gathered in large flocks everywhere and anywhere that food or preferred nesting and roosting sites existed, Chicagoans and rock doves coexisted in the best way that they could.
I was forever amused by the interactions between people and pigeons; some were obviously annoyed, as they hurried along city sidewalks through sedentary flocks, whereas others went out of their way to feed the birds or coax them to come even closer. Some people loved pigeons, but most seemed to either detest the birds or simply cope with them.
Pigeons belong to the family Columbidae. This is the same family that doves belong to. In all, 14 different species of pigeons and doves are found in North America. Here in Minnesota, we have two commonly observed species: mourning dove and rock dove, the latter being the feral pigeon. And while records of other species of doves do exist in Minnesota, you are likely to see only the mourning and rock doves here in the Northland.
Like the European starling and house sparrow, sometimes called English sparrow, rock doves have their roots in Europe. French settlers introduced the domestic pigeon to North America in the early 1600s. Thus, our non-native pigeons are descendents of the Old World pigeons. In Europe, pure and wild rock doves do exist yet today; these birds apparently only nest on coastal cliffs in Ireland and Scotland.
Wild rock doves' plumage is typically gray in color, darker gray on the head and breast, with two broad black wingbars. Other field marks include a white rump and a white "cere" (the fleshy covering on the upper part of a pigeon's beak), and falcon-like triangular-shaped wings with sharp pointed tips. Still, differences do exist. Pigeons exhibit a wide array of plumage coloration - from the natural rock dove plumage noted above, to patterns of dark, pied, checkered and brown and many colors and patterns in between.
Today, pigeons are one of the most recognizable and plentiful birds in both urban and rural communities. Pigeon fanciers, who train the birds for homing and racing contests, raise many thousands of domestic pigeons every year. Additionally, abundant numbers of these domesticated pigeons end up becoming a part of the feral population as escapees.
Not surprisingly, pigeon populations were never taken very seriously by birders and scientists. It wasn't until the Breeding Bird Survey began in 1966 that pigeons were officially reported and recorded. And it wasn't until 1974 when people participating in the National Audubon Society's Annual Christmas Bird Counts began tallying rock doves. According to these data sets, the National Biological Service reports that rock dove populations in North America have stabilized in recent times, following a sharp increase in the 1960s and 1970s.
Compared to many species of birds, pigeons and doves are unique. Some of their behaviors and physiology are worth mentioning. For example, pigeons tend to mate for life, and the pair raises their offspring together. The birds are said to be excellent parents. Instead of feeding their young like most other birds do, that is with insects or other foods carried and brought to the nest and nestlings, pigeons and doves regurgitate a liquid into the gaping mouths of their young. The thick substance is referred to as "crop milk" or "pigeon milk," which is part of the digestive system.
This highly nutritious food actually contains more protein and fat than human or cow milk and is very high in vitamins A and B. As time progresses, usually when the chicks are about a week old, the parents begin mixing seeds into the crop milk until a diet of seeds replace the milk substance altogether.
Another interesting pigeon and dove trait is the manner in which the birds drink water. As you know, most birds dip their bills into water, draw the drink into their beaks, but then must throw their heads back in order to swallow. Doves and pigeons have the ability to immerse their bills and drink continuously, like drinking through a straw.
No discussion about pigeons would be complete without mention of one species, and one particular individual of that species, of North American pigeon that is now extinct. Martha, named after Martha Washington, was the last passenger pigeon known to exist.
Martha died in 1914 at the Cincinnati Zoological Gardens at the age of 29. Once numbering between three and five billion, it is thought that passenger pigeons constituted between 25 and 40 percent of the total bird population in the United States. Unregulated hunting and habitat destruction wiped out the entire wild population by the early 1900s.
Coupled with our native mourning dove population of about 400 million, the current dove and pigeon population doesn't approach the magnitude that the passenger pigeon population once had. Even so, pigeons and doves, including the gentle, cooing, social, and docile "rock dove" so common in cities and farms, are here to stay as we get out and enjoy the great outdoors.
Blane Klemek is the Bemidji area assistant wildlife manager, DNR Division of Fish & Wildlife. He can be reached at firstname.lastname@example.org