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The Purple Martin is North America’s largest swallow and one of the best known and most popular migratory birds in North America. Martins and people enjoy a certain similarity: they both like to live in colonies.

The Purple Martin is a Neotropical migrant that nests throughout Wisconsin but whose population here is declining. Purple Martins were either confirmed or given a probable breeding status in approximately a quarter of the state’s topographic quads during the 1995-2000 field seasons for the Wisconsin Breeding Bird Atlas. They were more common in the southeastern and east-central regions of the state.

Bird City criteria Working to increase the population of Purple Martins is a wonderful opportunity for Wisconsin communities interested in being designated as a Bird City Wisconsin (BCW) community.    Working on a Purple Martin project would help a community to achieve BCW status.

What sort of research is being done locally on martins? On July 13, 2010, with support from Bird City Wisconsin, Noel and Seth Cutright, Carl Schwartz and boat captain Tom Schaefer surveyed Purple Martin nesting structures for almost 12 hours from the water along the entire Lake Winnebago shoreline. Lake Winnebago, located in the counties of Calumet, Fond du Lac, and Winnebago, is about 30 by 10 miles and has 88　miles of shoreline. The cities of Fond du Lac, Menasha, Neenah, and Oshkosh are located along the shore.

Using four sets of eyes and binoculars, they attempted to detect every Purple Martin nesting structure located on the shore. They recorded 228 poles at 131 locations that supported 200 wooden or aluminum nesting structures (103 wooden, 97 aluminum) and supplied 3,078 nest holes. The number of holes available at a site ranged between 5 and 98. Of these available holes, 349 were gourds, including 4 that were dried gourd fruit, and 26 that were plastic tubes or cylinders.

A third of the sites where there was only a wooden structure(s) available were active, whereas where only aluminum housing was available, half of the sites were active. Wooden housing tended to be older and sometimes more dilapidated, was placed in less suitable locations to attract martins than aluminum housing, and served as ideal House Sparrow apartments. Sites where aluminum housing plus gourds were available had the highest active colony success.

Reproductive success in aluminum houses has been found to be no better than in wooden houses. However, aluminum houses are recommended from a management perspective because they are lightweight, encouraging people to lower them for nest cleanouts. Hinged doors, which few wooden houses have, further facilitate cleaning and maintenance. Aluminum houses do not require as much repair and repainting as wooden houses. For these reasons, aluminum houses enjoy longer life and ultimately produce more Purple Martins, while starlings and House Sparrows take over neglected wooden houses.

According to Wisconsin’s Wildlife Action Plan, there are 284 native bird species for which Wisconsin provides important breeding, wintering, or migratory habitat. Of these, 84 (30%) have been identified as Species of Greatest Conservation Need (SGCN), which are species that have low and/or declining populations that are in need of conservation action. However, the Purple Martin is not among them.

This  article was adapted from a paper publi in the "Passenger Pigeon," the quarterly journal of the Wisconsin Society for Ornithology. Its principal author was Noel Cutright, past president and current historian of WSO and a member of the Bird City Wisconsin steering committee.

Because of the lack of conservation priority being given to martins in Wisconsin, a specific monitoring program for the Purple Martin is not currently in place. This leaves the Breeding Bird Survey as the only real population monitoring program. Across North America, the Purple Martin population has been stable over the years 1966–2007. However, the BBS trend for Wisconsin shows a significant decline of 6.2% per year between 1980 and 2007. In neighboring states, the significant annual declines are 10.8% for Michigan and 6.6% for Minnesota, but there is only a nonsignificant decline of 0.8% for Illinois and 0.4% for Iowa.

To bridge the science-management gap, Bird City Wisconsin is joining the Martin paper's authors in strongly recommending the formation of a Purple Martin working group in Wisconsin, where the situation is most urgent. Since no Wisconsin-based organization has taken action to address the decline, we believe that formation of a martin organization is likely necessary to halt the decline. By default, the management of Purple Martins has remained largely up to layperson landlords and their supporting martin organizations outside the state.

Cutright argued in his paper that it is often more productive to expand the size of an existing martin colony than to attempt to attract them to a new location. One of the shining examples of this is in the city of Oshkosh where the Oshkosh Bird Club has worked at the city’s water treatment plant to establish and increase a martin colony.

In 1989, there was only one old martin house at the site that was in bad need of repair, had not been cleaned out in years, and was full of House Sparrows. However, one pair of martins attempted to nest in it. Tom Ziebell repaired and painted the house in 1990, and the Bird Club purchased six gourds. Three pairs nested there in 1990. Since then, more houses and gourds have been added, with 52 possible nest sites now available for martins. The last five years has seen 40-45 of the nest holes occupied by martins, and in 2010, it looks like about 45-50 are in use. More concerted efforts by individuals and groups like this are sorely needed.

The Lake Winnebago shoreline survey discovered a few active colonies on public property. There are 15 gourds in Fond du Lac County’s Columbia Park located west of the Village of Pipe. Although only 15 acres in size, Columbia Park has ideal habitat to allow expansion of this colony. Adjacent to Columbia Park is the 100-acre Shaginappi Park. High Cliff State Park, the largest state-owned recreation land on Lake Winnebago, has a very active colony with 54 martin holes available near the marina on this 1,187-acre property. Finally, the Stockbridge Harbor, which became fully operational in 1998, has a nice colony of martins and 22 holes available. Each of these colonies could be expanded easily. It would only take the energy and devotion of a few individuals or the appropriate organization to make this happen.