By CLAUDIA DREIFUS
NY Times Published: January 14, 2013

For much of the year, Bernd Heinrich spends his time at a cabin he built in a remote forest in western Maine. The cabin has no indoor plumbing and no electricity, he says — just a tree growing inside it.

An emeritus biology professor at the University of Vermont, Dr. Heinrich, 72, sees the New England forest as a living laboratory to study nature’s changes. Over the years he has translated his observations into 17 popular books on nature and the animal world, including ones on bumblebees, dung beetles, owls and geese. Also among these works are a memoir and a 2002 book on running, “Why We Run: A Natural History.” (In the 1980s, Dr. Heinrich was a champion marathoner.)

And lately he has been studying how animals die.

Dr. Heinrich’s book “Life Everlasting: The Animal Way of Death” was published last summer by Houghton Mifflin Harcourt.

We spoke at the Trailside Nature Museum on the Ward Pound Ridge Reservation in northern Westchester County, and later by telephone. A condensed and edited version of the interviews follows.

How did you come to write a book about animal death?

I first started thinking about it when a former student, Bill, wrote saying he was terminally ill and what would I think about his having a “sky burial” on my property in Maine? He wanted to leave his body to the ravens. Bill did not want to be cremated or buried in a sealed box. He wanted to be recycled and have his body provide food for other creatures.

Bill’s letter got me thinking about the different ways animals are recycled in natural ecology and about how scavengers cleanse the world so there’s room for new life.

In many ways, this was a subject I’d been circling for a long time. Over the years, I’d studied ravens and beetles, scavengers who are key actors in natural recycling. I may have felt some affinity for them because we — my parents, my sister and I — had once been scavengers ourselves.

Scavengers?

Yes. At the end of World War II, in Germany, my family escaped the advancing Red Army and lived in the forest. My father was an entomologist, a wasp specialist, and he believed the most awful place to be in a war was a city. We ate by scavenging. We trapped mice. I remember finding a dead boar, and my sister and I ate it.

But to return to Bill: I wondered if his idea was feasible. What if we put him out and no ravens came? I could imagine that even if they did eat him, there might be a human skull lying around and the next thing, the police would be up there. No, this wasn’t practical! I sent Bill a note saying that regrettably I could not help him.

But now I began doing little experiments on my property. I’d been working on a book about beetles and I thought this might make a chapter. So I put out roadkill — mice, raccoon, a shrew — and then watched for who came and how nature’s undertakers — burying beetles, maggots, gorgeous green bottle flies — broke the carcass down.

The entire scene was about transformation. A mouse would die and get eaten and it became beetles. Or its molecules could become part of a hawk or an owl. I looked at a moose and a deer carcass and I was fascinated by how quickly even big things disappeared in nature. So before I knew it, this chapter had grown into a book!

Did you find it difficult to work with roadkill?

Aside from the ick factor, a carcass is a very active scene. It’s not so much about death as life. The carcass provides a huge amount of concentrated food for the animals who are recyclers. So you get competition and all kinds of interesting animal behavior as they try to get access to it. If the food is being defended, that’s interesting. And if all kinds of animals want it, that’s even more interesting.

Some of the recyclers I enjoyed more than others. Ravens are very appealing. I’ve never met a raven I didn’t like. I can’t find maggots appealing, but after a while I did get used to them. Today I can watch maggots and find them quite interesting. Just this summer, I put out a raccoon carcass and it was almost consumed by maggots and there was nothing left, no meat whatsoever, in three days. And then, I saw a whole cohort leave, thousands of them, and they left the raccoon as a group, all in one direction.

What do you think was going on?

I still don’t have all the answers. I can give you some hypothesis. They were heading for the sun, moving towards light. They had to leave the carcass because they’d finished it off and there wasn’t any food left. Most creatures, if they don’t have food, they move on. Why shouldn’t a maggot? The question still is why did they all go at once? This was in the summer and if you move in a group, you reduce the surface area and lose less water. I’ll be doing more research on this next summer.

Many scavenger species have a bad reputation. In some cultures, there’s a hatred for vultures and ravens. Do you understand it?

It’s because of their association with death — they are blamed for it. Ravens get blamed a lot for killing a lot of things when, in fact, they mostly eat the dead and the nearly dead. It’s an illogical association that comes from a lack of understanding of what these animals do. Consider what would happen in the ocean if nothing ate the dead fish. Eventually, the ocean would be up to the top with dead fish. If there were no recyclers, nature would stop.

Many of the scavenger species are now endangered. What is happening to them?

With some of the larger scavengers — the condors and the vultures — we’ve hunted out their food base. There’s nothing left for them to eat. Also, we are using poisons to kill competitors for our own food sources — rats and mice. Then owls and hawks eat these poisoned rodents and die.

With some of the vultures, there have been population crashes because some of the medication fed to livestock is toxic to them. They eat dead cattle, traditional food, and then they die.

I was just reading about how the Parsis of India have sky burials as part of their religion. Lately, they’ve begun breeding vultures for their ceremoniesbecause there aren’t enough wild ones left. It’s tragic. The ecosystem is very complex and we can’t know what will happen if these animals disappear.

Are humans and their remains part of that complex ecosystem?

I think so. But human death is becoming more and more divorced from nature. We pump our dead with polluting chemicals like formaldehyde, put them into airtight boxes and then plant them in precious real estate that could be used for agriculture. We think we’re denying death that way. The appealing thing about Bill’s idea was that he wouldn’t be consuming resources in death — his body would give back to natural world.

What ever became of Bill?

He’s still alive. Happily that sky burial hasn’t been required.