Thursday, November 18, 2010

The case of the louse and the passenger pigeon

The case of the louse and the passenger pigeon

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According to convention, detective stories begin with a dead body. But this one begins with a louse—a live louse. The trouble with this live louse? It was supposed to be dead, and not just sorry-he-just-couldn’t-pull-through, individual dead. This louse was supposed to be kaput as a species, absent from the face of the earth for nearly a hundred years.

The louse in question—whose status was even highlighted by his scientific name, Columbicola extinctus—was thought to have lived on only one host animal, the passenger pigeon. And the passenger pigeon’s time on earth ended with the demise of a bird named Martha at the Cincinnati Zoo, all the way back in 1914.

So what was Columbicola extinctus doing—very much alive—on another species of bird, the band-tailed pigeon, which occupies territory from Alaska to South America, on the eve of the twenty-first century?

That’s what Kevin Johnson wanted to know.

Johnson (pictured with museum specimen of a passenger pigeon, by L. Brian Stauffer) is currently an ornithologist with the Illinois Natural History Survey at the University of Illinois who studies the relationships between parasites, such as lice, and their bird hosts. But back at the time Columbicola extinctus was brought back from the dead, so to speak, he was working as a postdoctoral researcher at the University of Utah with one of the scientists who made the discovery.

The natural way to answer the question of why a louse that’s thought to be specific to one host is unexpectedly found on another is to look at how closely those host animals are related.

Previously, passenger pigeons had been thought to be most closely related to mourning doves, which are the doves you’re likely to know from seeing them in your yard. [Photo by author.] This association was based on shared physical characteristics, similarities in the coloring of their feathers and the length of their tails.

What Johnson set out to do, in cooperation with three colleagues from around the country, was establish how passenger pigeons were related to other species of pigeons and doves in terms of their genetic makeup.

I’d like to be able to portray the lab work and analysis they did as sexy and exciting, the way it is on CSI, but that’s beyond me as a writer. So I’ll give you the short version. Johnson and his colleagues compared genetic material from a museum specimen of a passenger pigeon with genetic material from 78 other species of pigeons and doves, a representative selection of the more than 300 species that occur worldwide today.

Using what they learned by comparing that genetic material, they constructed a revised evolutionary family tree for pigeons and doves, published as a scientific paper this year, which shows how far back you have to look to find ancestors that are shared by modern species.

On this tree, the now-extinct passenger pigeon occupies a branch much closer to the band-tailed pigeon than the mourning dove. So the louse, Columbicola extinctus, had gone on living after the demise of the passenger pigeon because the passenger pigeon was survived by an evolutionary cousin, the band-tailed pigeon. [USFWS photo by Gary Kramer.] And that cousin is also a suitable host for extinctus.

As we close the case of the louse that turned out not to be extinct, I realize I’ve said almost nothing about the life and death of the passenger pigeon as a species. So tune in next week for that story.

Friday, November 05, 2010

Campus composting: A step toward an integrated sustainable farm

campus composting: A step toward an integrated sustainable farm

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This week’s Environmental Almanac is a story in two parts.

Part one is the nitty-gritty tale of what happens to the vegetable scraps generated in the kitchen at Ikenberry Commons, the new, very green, student residence on the U of I campus.

To begin with, those vegetable scraps, which include all of the stuff you might expect, from lettuce stems to pineapple tops, are placed by Dining Services staff into bags that are kept separate from other trash, since they’re not headed for the landfill. Those bags, which are themselves biodegradable, accumulate in two large, rolling carts, which hold up to about 600 pounds each.

Those carts are picked up twice a week, on Monday and Thursday afternoons, by Matt Luedtke, who is with the U of I Environmental Change Institute. Luedtke retrieves the vegetable scraps from the kitchens at Ikenberry Commons to compost them, and I joined him for a run earlier this week.

He has been fortunate this semester to have help from undergraduate students in the College of Engineering who are part of a group called “Engineering in Service to Society.” On the day I met up with him, two of them came to help, Jason Kenyon, from Muscatine, Iowa, and Ryan Chan, from Hong Kong.

From the dining hall, Matt and his helpers drove the compostable material by pickup truck to a site on the U of I South Farms near the intersection of First Street and Windsor Road. There they loaded it with an equal volume of dry leaves into a manure spreader, which is essentially a small wagon with a rotating bar at the rear. [Photo: Matt Luedtke, left, and helpers Ryan Chan and Jason Kenyon, right, running the manure spreader to mix compost.] When the bar is engaged, a staggered line of paddles attached to it simultaneously mixes the vegetable scrap with the landscape material and flings off the back.

So far this Fall, the campus compost operation has generated two substantial mounds about twelve feet in diameter, with another having just been started. For now, when this material is ready to be used on a field, it will be transported a mile east to nourish the soil at the student farm, which, in turn, supplies fresh produce to Dining Services.

In the future, however, some on the U of I campus anticipate using the compost to nourish the soil on site, as part of a development known as the Integrated Sustainable Homestead.

This brings us to part two of today’s story, which is a vision for the future of the site at First and Windsor, which promises to become an important gateway to the U of I as Curtis Road is developed in Champaign.

Wes Jarrell, who is interim director of the Environmental Change Institute, sees today’s composting effort as a first step toward an operation that will demonstrate how food and energy can be produced sustainably at a local scale in Illinois. At the Integrated Sustainable Homestead, students would learn about where food comes from, how energy can be conserved and produced on a local scale, and how water can be used efficiently and sustainably, all through hands-on experience.

Picture, for example, a dormitory topped with solar panels, set among fields of a bioenergy crop, such as switchgrass, with forage plots for livestock and organic vegetable gardens filling out the scene.

You can get an even better idea of what the Integrated Sustainable Homestead might look like in a presentation by Matt Luedtke at the Environmental Change Institute’s annual symposium next Monday, November 8. The symposium, which is free and open to all, will take place from 2:00 – 5:00 p.m. at the iHotel and Conference Center. Details are available on the Web at