When people hear the name Nathan Leopold, they inevitably think about Leopold and Loeb. Brilliant young men Leopold and Loeb committed the “Crime of the Century” in 1924 Chicago. They killed a boy because they wanted to commit the perfect murder. But people may be surprised to learn that Leopold was an avid birder who is credited for increasing our knowledge of the then endangered bird called the Kirtland’s Warbler.
It’s one of many stories within Joel Greenberg’s new book, To Life: Jews Exploring Nature (Rutgers University Press, 2026), with a chapter written by Judith Winston. The book explores Jewish naturalists and biologists including the infamous Nathan Leopold. Greenberg wants to counter the view that Jewish folks have little interest in the natural world with these engaging histories of eight naturalists and biologists, covering myriad disciplines from mammals, disease-spreading insects, spiders, and birds.
I had the opportunity to talk with Joel Greenberg about his fascinating book. This interview has been edited for length and clarity.
Elisa Shoenberger
I was surprised by the chapter on Nathan Leopold. I knew of the murder but not about his birding background. I know you’ve talked about why you’ve included him in other interviews, but how have people reacted since you’ve done talks on the book?
Joel Greenberg
I was a little concerned about that too. Before the book was actually published, one person said, “Oh, you call it To Life, and then you have something on Leopold.” But what’s really interesting to me is that in almost all cases, university presses will send in the manuscripts to reviewers. One of the reviewers said that it was her favorite chapter, and then afterwards there’s a Jewish studies environmental scholar at Arizona State University, and she wrote a really nice blurb, so I wrote to her and thanked her, and she said, “Oh, my favorite chapter was with Nathan Leopold.”
Someone posted on Facebook, “I used to be interested in true murders, and now I’m an avid birder, and I am appalled at how much attention Aldo Leopold gets. Do people forget that he murdered a 12-year old kid?” I had to write to her and said, “You’re confusing Nathan with Aldo. They both had an interest in birds, but nothing else in common.”
Nathan Leopold interested people for a long time. I was told there are more than eighty different TV shows, poems, musicals, and other art forms. I was drawn to him in large measure because of his ornithological work. When I worked on A Feathered River Across the Sky: The Passenger Pigeon’s Flight to Extinction (2014), I also talked about the Kirtland’s Warbler as an example of an animal that was very rare that has expanded dramatically. I don’t think it’s even listed anymore on the endangered species list. Leopold made discoveries about the bird in 1923, a year before the murder, that possibly helped save the species.
Leopold was the first person to note the major reason why the bird was so rare. It’s because of parasitism by brown-headed cowbirds. That’s a native species, which itself has an interesting background. They would follow bison, and so they were mobile, so cowbirds had to find somewhere to put their eggs, which was other birds’ nests.
Leopold is connected to the birds, which I obviously have strong interest in. I saw my first Kirtland’s Warbler in 1968 when I went up to Michigan. That was really the only place that they bred at the time. They now breed in a few places in Wisconsin. I found Leopold totally fascinating.
Elisa Shoenberger
What was the most surprising thing you learned while working on this book?
Joel Greenberg
I wanted to include people whose Jewish identity varied, but my gosh, you have Phil Hershkovitz, a mammologist, whose children were shocked when they learned he was half Jewish. Their mother was a Catholic French woman. I knew his principal assistant, Barbara Brown, who was active in the Evanston North Shore Bird Club since the 1960s. She and her husband provided him with funding. She said that Hershkovitz participated in Pesach and the High Holidays.
Then there was Herb Levy, an arachnologist, who grew up in a Jewish family. They had a big Bar Mitzvah, but they had to flee Germany for obvious reasons in 1938. He never denied being Jewish, but when his daughter was interested in exploring her Jewish roots, he didn’t offer her anything.
I also didn’t realize this but for a lot of German Jews who came to the US to escape the Nazis, they still saw themselves as more German than Jewish. That was interesting to me, how people picked up religion later in life.
Elisa Shoenberger
How did Chicago play a role in the creation of the book? I know several stories include the Field Museum.
Joel Greenberg
The Field Museum is one of the largest natural history museums in the world. There’s the Smithsonian’s American Museum of Natural History, and the Natural History Museum in London. At least within the bird-collections field, the Field has one of the largest, and they’re certainly the top here in Chicago.
I have had a long relationship at the Field Museum. I was a research associate, which merely means that I could go inside for free, but given my interest in natural history locally, I had met a lot of curators. There were several scientists associated with the Field that I wrote about in the book like herpetologist Hymen Marx, and Leopold, of course. Hershkovitz was also affiliated with the Field; he was someone I had not heard of before, but somebody I knew was close to him.
Elisa Shoenberger
I was surprised at the incredible discoveries made by the people who you covered, such as Andrew Spielman and his work on mosquitos as disease vectors. Why do you think these folks are not household names given the influence of their work?
Joel Greenberg
Spielman co-wrote a book called Mosquitoes with author Michael D. Antonio. He’s written about Trump. He was a CNN commentator too. DeAntonio approached Spielman, because De Antonio felt that the same way you did. The book got good press, and was popular, but then 9/11 hit a couple months after the book came out, and obviously attention focused on other things.
Whether it would have made Spielman a household word, I don’t know. I don’t think there are many scientists that are household names. When you think of the best-known scientists, like the astrophysicists the late Carl Sagan and Neil deGrasse Tyson, they’re known because they had prominent media positions. Then there’s people like Anthony Fauci who worked on medical issues that were pegging everyone’s attention, like AIDS (and of course, COVID-19).
Elisa Shoenberger
How did you balance discussing the science and Judaism ritual and theology in the book?
Joel Greenberg
The first chapter is the one that talks the most about Jewish writings and thoughts. Judaism goes back a long time and there’s a whole bunch of different ideas about nature, a lot of which conflict with other texts. In the biographies of the eight people, religion is pretty small, maybe a page. I talk a lot more about what they did in terms of their work so the science is covered much more. The science discussions are all in the content of these people’s lives including their families and education, all the different things that make up people.
For instance, Joan Ehrenfeld’s graduate students told me two things in particular about her. She was an example for them. She had four kids with her husband, David. A lot of women in academia had to weigh academic success with having kids; some had to give up having children entirely, because they felt they needed to devote every minute to their publications and teachings. But Ehrenfeld provided them with an example of how you could do both, raise children and have a successful academic career.
She had two graduate students; one was Hindu and the other was an evangelical Protestant. Science is very secular so they were hesitant to talk about or really express their religious passions. The Ehrenfelds gave them role models. You could be a first-rate scientist and hold to your religious beliefs.
Elisa Shoenberger
What do you hope people will take away from this book?
Joel Greenberg
Beyond learning about these interesting people, one of my hopes is to introduce science through popular means and make it more accessible. I gave a talk recently in Oak Park, and someone said, “What is the point of studying spiders?” Well, if you’re going to understand biodiversity, you need to know how your efforts to preserve tracts of land affect everything, and you need to know how these organisms are connected to others. It doesn’t mean everyone’s going to be an arachnologist or, you know, somebody studying mosquitoes, but these interesting people did.
With Joan Ehrenfeld, who studied soil chemistry, I knew nothing about soil denitrification. I had to have some of her colleagues go over it with me. But by introducing these ideas to people through these characters, my hope is that more people would be aware of them and it would be less intimidating and make these important subjects more accessible.
Elisa Shoenberger
I hate when people ask why bother studying something. It all has value. But especially with ecosystems.
Joel Greenberg
I use the analogy of a plane. If a bolt flies off, you’re probably okay, but if at some point enough screws come apart, the plane is not going to be able to fly anymore.
At some point with these diseases and germs and whatnot, they’re part of the ecosystem, and when the ecosystem is disturbed and the organisms that they feed on disappear, then they seek out others, like Homo sapiens. There’s a lot of reasons why knowing this stuff is important.
NONFICTION
To Life: Jews Exploring Nature
By Joel Greenberg with Judith E. Winston
Rutgers University Press
Published May 12, 2026
