Sunday, March 8, 2009

Purple Martins need your help

A soaring, darting, chattering flock is on its way to the Show-Me State, and the Missouri Department of Conservation has a publication to help bird-lovers prepare for their arrival.

Purple martins – usually older males – may arrive in Missouri as early as the first week in February. A few were reported near Farmington March 1. However, most mature birds arrive and begin nesting in early April. Reports of martin arrivals in Missouri are available at purplemartin.org/scoutreport/scout.php?Y=2009&S=MO. A map showing the migration progress nationwide is found at http://purplemartin.org/scoutreport/.

Getting an early start exposes them to hazards associated with cold weather. A late, hard freeze can kill martins outright, as it did in 2007 when temperatures dipped into the teens for several days running during the first week of April. Just as serious, such weather kills the insects on which martins depend for food. John Miller, a self-proclaimed “obsessed purple martin hobbyist,” noticed the impact on the purple martin colony he helps maintain in St. Louis’s Forest Park and the Missouri Botanical Garden.

“Many mature martins had arrived, and many perished,” says Miller. “Even into the 2008 season, there were reports from around Missouri of vacant housing where birds had died during the spring a year earlier.”

Miller said the colonies hardest hit were small ones consisting of just a few birds. Enough martins survived in larger, more established colonies to permit them to rebuild their populations fairly quickly.

While cold weather probably limits the northern extent of purple martins’ North American range, the hardy birds establish colonies all the way into Canada. Miller said the freak freeze of 2007 had little effect on martin numbers continent-wide, as indicated by observations in the North American Breeding Bird Survey. Martin numbers have increased slightly in Missouri since the first survey in 1965. For more information, visit mdc.mo.gov/8048.

Purple martins are the only wild birds in Missouri that rely almost exclusively on humans for nesting sites. Their association with humans began thousands of years before Columbus discovered North America. Indians hung gourds with entrance holes cut in them from poles to attract the birds, which devour flying insects, such as horseflies and wasps. For more about the history of martins-human association, visit purplemartin.org/main/history.html.

Miller, a member of the Purple Martin Conservation Association, has made a second career of being a martin landlord. He says the design and placement of martin houses and other nesting structures can be critical to a colony’s success. Nesting success also depends heavily on conscientious maintenance to get rid of old nesting material and the parasites it can harbor and on quick action when starlings or house sparrows try to move in on martin’s territory.

“Hosting martins is an opportunity to become an amateur wildlife biologist,” says Miller. “Martins thrive at sites where humans provide good housing that protects nestlings and allows more to fledge. There has been a wealth of information learned in the past decade based on research by the Purple Martin Conservation Association and members in the field. My advice to prospective purple martin landlords is to learn all they can.”

One way to learn about purple martins and their care is by obtaining a copy of “Missouri’s Purple Martins,” a comprehensive, 12-page booklet with illustrations. The booklet is available at mdc.mo.gov/12199. Printed copies are available by writing to MDC, Missouri’s Purple Martins, P.O. Box 180, Jefferson City, MO 65102-0180, or e-mail pubstaff@mdc.mo.gov.

“These are enchanting birds,” says Miller. “They can be a window on the larger natural world even as broad as global weather patterns and the health of the planet. They lack the bright coloring of our delightful bluebird, but they are highly animated and seem to be just joyous. They can make your heart soar.”--Jim Low, Department of Conservation

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