BAR HARBOR — Based at his camp called “Kaflunk” in western Maine, biologist Bernd Heinrich spent four years trying to solve the riddle of the raven in winter. His writings and lectures have helped to crack the cover of the mysterious bird.

Beginning the work in the mid-1980s at what was then a tarpaper shack at the edge of Mount Blue State Park, the former scholar of bumblebees immersed himself in studying the strange, “left-wing” social behavior of the massive black birds often confused with crows.

The heart of the riddle was this: Why should typically solitary birds such as ravens share their food in the dead of winter, particularly in a raucous fashion, essentially advertising the presence of a meal to other competitors?

The question may seem academic, but at last week’s College of the Atlantic Summer Series presentation, Heinrich’s discussion of the question also shed light on other interesting aspects of the bird, as had his book on the subject.

Hailed by The New York Times as “one of the notable books” of 1989, Heinrich’s “Ravens in Winter,” written from his studies, reads like a combination diary, naturalist essay and detective story.

Heinrich saw his first ravens as a young child in his native Germany in the 1940s. He did not see another until the 1950s, when he and a companion saw one swoop over a ridge toward Mount Tumbledown in the Maine woods.

Then an avid egg collector, Heinrich never forgot the thrill of finding the first of many ravens’ nests 10 years later. His interest culminated in 1984, when, in Maine on sabbatical from the University of Vermont, the zoology professor saw a crowd of ravens near where he had intermittently seen the birds for decades.

At his presentation this week, Heinrich first set the stage for the synopsis of his detective story, explaining how to identify ravens.

“If you hear something strange in the woods and have no idea what it is, it’s probably a raven,” he said. The sometimes iridescent bird is much larger than a crow, with a heavier bill and a wedge rather than square-shaped tail. Unlike the crow, whose flight is characterized by steady flapping, ravens can soar like hawks.

Because they flourish in a variety of settings, ravens increasingly can be found in urban as well as rural areas — snacking in a Dunkin’ Donuts dumpster in the Southwest, nesting in treetops in the Maine Woods, or swooping from cliffs above the Arctic circle.

Yet a person could go many miles or months and never see one.

Nesting in March, ravens are most visible in wintertime. For Heinrich, winter study meant hauling bait carcasses up a snowy hillside and rising at dawn to crouch behind a blind awaiting his subjects’ arrival.

Some days there were none.

On better days, ravens “quork” sounds filled the air, and crowds of the birds appeared. Among other things, Heinrich learned that he had to cut open the carcasses for the ravens, whose preferred diet comprises proteins and starches. At least one raven particularly favored french fries and ice cream.

In group situations, a dominant bird would stand with erect posture, its feathers slightly raised from its body. The prolonged presence of a dominant bird actually appeared to stall the maturation of juvenile birds.

Ravens generally mate for life and can be long-lived, with one in captivity reaching a record 61 years of age. But while Heinrich isn’t certain how most meet their deaths, he said he believes the mortality rate among wild ravens is relatively high. The need to compensate for losses and perpetuate the species may help explain why ravens can annually lay up to seven eggs at a time.

Setting out 135 baits totaling 8 tons of meat over four winters, Heinrich noted that at least 90 percent of the baits were consumed by “crowds” of from 15 to nearly 300 birds, quite a phenomenon considering ravens are “not particularly common,” rarely congregate in such numbers in other situations and are considered shy.

Heinrich’s conclusions suggest a behavior pattern surprisingly not duplicated in other bird species, including jays and crows, which would feed at a carcass, but not in large numbers.

An unmated young raven seeking company appears to invite other “singles” to join him upon finding food. Heinrich said he believes the behavior serves to maintain the raven’s access to the food. It may also allow the bird, before a large group of onlookers, to show off his ability to act as provider, rendering him a more attractive mate.

Heinrich’s new book, “In the Maine Woods,” will be published this fall.