Bob Pickett’s Appalachian Nature: March and the Pigeon Story
With March comes the birth of a new season. By the end of this month, spotted salamanders and wood frogs will have completed their mating for the year; mourning doves and starlings will be on their first egg brood of the year; and I will have already seen my first hepatica, bloodroot, trout lily, harbinger of spring, and cut—leaf toothwort.
If you’re a late riser and miss the March natural events, you would be missing the magnificent massing of tundra swans that use the area below the Conowingo Dam along the Susquehanna River in Pennsylvania as a staging area for their long migration to the tundra north of the Hudson Bay. For the first two weeks of March, up to 10,000 swans can be seen here and at the nearby Middle Creek Wildlife Management Area (WMA). For more information on the Middle Creek WMA, go to www.fieldtrip.com/pa/773315l2.htm or do a search on the Internet.
Salamanders Start Their Season
For me, the inaugural event of the season is the gathering of the spotted salamanders. On the first good rain event lasting into the evening in early to mid-March, with temperatures around 40 degrees, brave the weather and visit your local vernal pools. If you hit it right, you will find hundreds of spotted salamanders writhing in masses, known as congresses, in the midst of an all-night orgy. But if you miss the night of their passionate performance, you may have to wait another year to observe them, since they will leave the pools as quickly as they arrived, returning to the underground homes they occupy the other 360+ days of the year.
I have a site I check each year, near the Audubon Naturalist Society headquarters. It is on Jones Mill Road, just inside of the beltway (in sight of the Mormon Temple). Park at the playground, take the footbridge over Rock Creek, and you’ll find the pools at the base of the hillside. While several of the past years found these vernal pools dry, I’m counting on their being full this year!
The wood frog, like the spotted salamander, also breeds explosively, unlike most amphibian species such as spring peepers, which exhibit a more extended breeding period. The wood frog normally makes its appearance at vernal pools and permanent ponds early in March for a week of intensive courting and mating. The frogs’ distinctive duck— like quacking will be heard with, or even just prior to, the more familiar calls of our spring peepers. A week or so later, count on their being joined by the snoring of the pickerel frog and, if you’re lucky; the ascending trill of the vanishing upland chorus frog.
The Sad Passenger Pigeon Saga
The one March event none of us will see is the spring northern migration of the passenger pigeons. It is believed that this species once constituted 25 to 40 per cent of the total bird population of the United States. It is estimated that there were 3 billion to 5 billion passenger pigeons at the time Europeans arrived in America. The migratory flights of the passenger pigeon were spectacular. The birds flew at an estimated speed of about 60 miles an hour. Observers reported the sky would be darkened by huge flocks that passed overhead. In 1808, ornithologist Alexander Wilson observed a flock in Kentucky he estimated at a mile wide that passed him for four hours. Based on his calculations, the flock was estimated at 2.25 billion birds. These colonial birds would summer in massive cities. Surprisingly, for their staggering numbers, only 10 or 12 such encampments would exist in any year, congregating in two main areas, one in New York or Pennsylvania, the other in the Great Lakes region. One site in Wisconsin in 1871 contained an estimated 136 million birds spread out over an 850-square-mile area.
Densities in some colonies were as great as a hundred nests per tree. One can only imagine the enormous impact on the ecology of the nesting grounds. The sheer weight of the birds (slightly larger than mourning doves, our other native dove) mangled trees by breaking off trunks. Breaking branches would kill both adults and eggs and add to the tremendous wash of guano that covered the ground. The tremendous cacophony of the birds reportedly could be sensed from miles away (as could, perhaps, the smell!).
The passenger pigeon’s technique of survival had been based on mass numbers to overwhelm predators. John James Audubon wrote, “The howling of wolves now reached our ears, and the foxes, lynxes, cougars, bears, raccoons, opossums, and pole-cats [skunks] were seen sneaking off from the spot, whilst eagles and hawks of different species, accompanied by a crowd of vultures, came to supplant them and enjoy their share of the spoil.” It is believed that peregrine falcons specialized in hunting passenger pigeons, as did goshawks in the more northerly breeding areas.
People Step In
However Man changed the rules. And, with the telegraph and railroad, the fate of the colonial birds was sealed. With the knowledge of roosting site locations and with easy transportation to get to the sites, an annual mass hunting began on an unprecedented scale. By 1850 the destruction of the pigeons was in full force, and by 1860 it was noticed that the numbers of birds seemed to be decreasing, but still the slaughter continued.
A seasonal market for passenger pigeons existed for a month each year from April into May. By June, the markets were glutted with pigeons, the nesting populations were scattered, and the hunters largely dispersed.
One of the last large encampments of passenger pigeons occurred at Petroskey, Mich., in 1878. Here 50,000 birds per day were killed, and this rate continued for nearly five months. When the adult birds that survived this massacre attempted second nestings at new sites, they were soon located by the professional hunters and killed before they had a chance to raise any young.
Perhaps having an even greater impact than the hunting itself was the disruption of the breeding activity, driving adults from their colonies so that in some years there was a complete nesting failure.
The life history of this bird was based on mass colonial nesting sites. Bearing only one egg per brood, the remaining populations could not maintain the stock, and a final freefall into extinction occurred over the course of just some 20 years. By the early 1890s, the passenger pigeon had almost completely disappeared. Perhaps the last free-flying pigeon was shot in 1902 in McKean County, Pa., and in 1914, the last captive bird died in the Cincinnati Zoo. ~
4 March 2003 — Potomac Appalachian