'Dog Days, Raven Nights': John and Colleen Marzluff chronicle the complicated world of ravens

University of Washington professor of wildlife science John Marzluff and his wife, wildlife biologist Colleen Marzluff, were newlywed and newly graduated when they signed on as researchers in a U.S. National Science Foundation-funded project in cooperation with biologist Bernd Heinrich "to solve a raven mystery" in Maine. From 1988 to 1991 they explored this question: Why, they wondered, do ravens share food?

The goal of their recently published, fascinating and beautifully illustrated book about their experience, the couple explains, is "to share our perceptions and discoveries with a wide audience" as well as to motivate young scientists. In "Dog Days, Raven Nights" (Yale University Press, 323 pp., $28), both write details of their behavioral studies in the field and at a giant aviary they built with generous local help. In fact, the story of their own lives — fitting in, making friends, attending auctions, church suppers and dog races — weaves a delightful, complementary thread to their professional works and days.

Early on, they trap a number of ravens, which, once fitted with leg bands of various color combinations and wing tags for identification, are released into the wire-mesh aviary. It is designed with two long arms and a central space — the whole thing encloses an acre — with doors allowing experiments with different groups.

Like chickens, they write, ravens have a hierarchy. The chain of command is fairly consistent, implying the birds "know each other as individuals." An alpha male is generally in charge, and adults dominate juveniles. But introduce food and, depending on who discovers it and if the alpha male's absent, dynamics change instantly. The next in line moves up. While it's generally another male, a female of high rank might take over.

The Marzluffs accumulate all sorts of "raven chow," including roadkill and dead livestock, lungs and livers, squashed opossums and earthworms, hauling it to their hungry charges with the help of dogs Topper, a Collie mutt, and Sitka, a husky. To readers having no familiarity with scientific study, the text is engaging and enlightening, revealing the researchers' pleasures and problems. Extreme cold, snow, rain, mud, stinky meat, climbing high into trees, bad roads, black flies ... it's all here, along with the constant quest for answers.

What purposes do the ravens' night roosts serve, for instance? Why do they set off together in the morning, but arrive higgledy- piggledy in the evening? Why do they soar? Why do they "yell," that is, make calls that perhaps "recruit" others to feast? Why and how do "gangs" form? What are the benefits of flocking?

In the second year, the Marzluffs raise 10 babies Heinrich brings from Vermont. When the couple later compares ravens raising chicks, they show a firsthand appreciation for nurturing those noisy, demanding, bottomless pits. And the Marzluffs make the interesting observation that the raven-raised babies have far less fear of new foods than the ones brought up in captivity.

Interspersed with their field work are outings to dog races, social events and John's search for a job once this post-doc research ends. Both mention stress during work with Heinrich, and their uncertainties about the future. But they give good account of their studies, and while they don't claim to have found definitive answers to all questions, they have "opened the door" to future research. And they've opened another door, as hoped, welcoming a wide reading audience, too.