Biologist and best-selling author Bernd Heinrich has spent years spying on his neighbors. Using his camp in western Maine as a field laboratory, he observes the animal life in his backyard woods.

Lately, he has trained his eye on the final stage of the life cycle: What happens when animals die? What species convene at the site of a carcass, and what takes place there? And how do humans fit, or intervene, in the process?

In “Life Everlasting: The Animal Way of Death,” Heinrich explores these questions with his characteristic elan. At 72, the author has the energy of a much younger man and the curiosity of a child. So, as he watches the intricate routine of burying beetles, working in pairs, carrying a dead mouse to the soil, he startles at the recognition of their conduct. While feeding on the carcass, the beetles engage in what Heinrich calls “a lot of random-seeming mating.”

The convergence of a death site into a lively place of renewal is precisely what this book is about. Indeed, the impetus for the book came from an ailing friend, who asked whether a “green burial” might be possible on Heinrich’s Maine property. That question begat countless others, and so this project began.

“Undertaking surely is an ancient heritage,” Heinrich says. “For every individual that walks, one dies, and each one becomes a resource of highly concentrated food. The larger the carcass, the more food there is for those who feed on it.”

Heinrich provides case studies of sorts, detailing the collaborations among species. When the author deposits a road-killed squirrel in the clearing of his woods, he waits to see what will transpire.

Sure enough, a raven arrives and pulls out the eyes and fur but, unable to tear through the skin, flies off. Heinrich promptly runs outside, slits open the carcass and repairs to his couch, hoping for the raven’s return. Instead, a turkey vulture descends and feeds at the site. Half an hour later, with the squirrel stripped nearly clean, the author wonders which species might finish the job. The next morning, a raven supplies the answer.

This is not a book for the squeamish. Included are graphic descriptions of rotting entrails, carcasses sliced open, even a whale corpse that explodes from internal decay. Heinrich doesn’t exactly revel in these depictions, but he tends to be cheerfully specific. In his line of work, every tiny fact or feature adds new data.

Yet there’s also an upside to so much detail. Heinrich is an equal-opportunity narrator, engaged as much by the playful behaviors of his animal subjects as their undertaking skills.

After portraying the balletic movement of ravens in flight, the author concludes that, given the choice, he’d like to be reincarnated as a raven.

Heinrich wears many hats in this book — scientist, activist, philosopher and sleuth. In each role, he collects evidence and puzzles over its meaning. From the forests of Maine to the Serengeti plains, he extols the symbiotic ties among different species. Here, for instance, he describes the aftermath of a dead giraffe in East Africa:

“One giraffe died, but a dozen lions, hyenas, and jackals and perhaps hundreds of vultures were fed,” he says. “Thousands of dung beetles had a feast, and the plains would grow more grass.”

As that quote suggests, Heinrich can sound, at times, almost biblical. Nor does he confine himself to a single idiom. The book combines elements of CSI, natural history, even a Sunday sermon.

Not surprisingly, Heinrich advocates a more natural, less-managed approach to animal death and recycling, noting that humans have our own agendas.

“If an animal that is deemed not suitable as food for us dies, we also deem it unsuitable for availability to others,” he says. “Even the road-killed deer and other animals that the highway department picks off the roads are disposed of by burying. Vultures would do the job better if we let them.”

Joan Silverman of Kennebunk writes op-eds, essays and book reviews for numerous publications.