Published: May 12, 2017

Spring Migration Notes...By a Murderer

Gretchen Rings, Museum Librarian and Head of Library Collections, Library


Before he became part of the infamous duo Leopold and Loeb, convicted for kidnapping and murder, Nathan Leopold was a birder.

On November 5, 1950, Curator of Mammalogy Colin Sanborn received an extraordinary letter at the Museum (then the Chicago Museum of Natural History). It began as follows:

Dear Colin,

I should like to make a rather unusual request of you. Some twenty-five years ago I gave the then Field Museum several specimens from my bird collection. Included among them was a habitat group of Kirtland's Warblers, consisting of the two adults and four nestlings in the nest, mounted by Ashley Hine...I know that the Museum used to have souvenir photograph postcards of many of its mounted groups on sale to the public. Could you find out for me whether such a photo was ever made of this Kirtland's Warbler group, and if so, let me know how I can get one?

It wasn't the request itself that was so unusual: individuals (or their descendants) frequently inquired about a specimen donated to the Museum. It was the letter's author that made it stand out: Nathan Leopold, Jr. Prior to becoming part of the infamous duo Leopold and Loeb, convicted for kidnapping and murdering 14-year-old neighbor Bobby Franks, Leopold had been a birder and ornithologist. Writing from prison in Joliet, Illinois, he hoped to receive a photograph of a group of specimens he'd donated as a very young man.

The cover of the copy of Spring Migration Notes in the Field's Library and digitized by the Biodiversity Heritage Library. 

The book on Chicago birds was authored by James D. Watson, George Porter Lewis, and a young Nathan F. Leopold, Jr.

In addition to specimens from Loeb—the Field Museum also has a Cooper's Hawk and a praying mantis—our Library owns one of only a couple of known copies of a booklet called Spring Migration Notes of the Chicago Area that Leopold helped compile. He was just 15 years old when the booklet was published. 

Joshua Engel, a research assistant at the Field, writes, "This little booklet has so much history, it's hard to know even where to begin. Let's start with the fact that the first author, James D. Watson, is the father of one of the most famous scientists of the 20th century, also named James D. Watson, who along with Francis Crick is credited with the discovery of the structure of DNA. But that's the least of it. The third author is even more intriguing. A budding young ornithologist, Nathan Leopold would spend the bulk of his adult life in prison for the murder of Bobby Franks, one of the most famous crimes of the 20th century."

James D. Watson the younger describes how his father met Leopold: "It was in Jackson Park in 1919 that Dad had met the extraordinarily talented but socially awkward sixteen-year-old University of Chicago student Nathan Leopold, who was equally obsessive about spotting rare birds. In June 1923, Leopold's wealthy father financed a birding expedition so Nathan and my dad could go to the jack pine barrens above Flint, Michigan, in search of the Kirtland's Warbler. In their pursuit of this rarest of all warblers, they were accompanied by their fellow Chicago ornithologists George Porter Lewis and Sidney Stein, and in addition by Nathan's boyhood friend Richard Loeb, whose family helped form the growing Sears, Roebuck store empire."

Yellowed paper with blue typewriter print and Nathan Leopold’s signature in black ink

Nathan Leopold's letter to ornithologist Ruthven Deane. This letter was enclosed when Deane donated his copy of Spring Migration Notes to the Museum. 

Our copy of Spring Migration Notes of The Chicago Area, published in 1920, is now stored in our Library's Mary W. Runnells Rare Book Room. Because of its historical value, it was added to the Biodiversity Heritage Library, including the type-written, hand-signed letter on page four from young Nathan Leopold to Ruthven Deane, a leading ornithologist of his time and a resident of Chicago, who eventually donated part of his collection of specimens to the Museum (as Leopold did when he went to jail). The cover of this copy even says "Compliments of the authors," presumably written by Leopold. 

Aside from the fascinating backstory, there's the actual information that the booklet contains: a priceless indication of what the bird life of Chicago was like in the early part of the 20th century. At the time, many wetland birds that are now rare or altogether gone as breeding birds were still common, an indication of the destruction of wetlands in the Chicago area over the last century.  This includes birds like Black Tern (which the authors say "Breeds commonly"), King Rail ("Common summer resident"), and Wilson's Phalarope ("Nests in the Calumet region").

On the other hand, grassland birds were already declining, with many formerly common birds becoming rare. For example, the Greater Prairie-Chicken was "A formerly abundant permanent resident; now rather rare." Northern Bobwhite was "A formerly very common permanent resident, but now rather rare." Loggerhead Shrike, which then was known as Migrant Shrike, was a "Fairly common summer resident." Today, you have to go hundreds of miles from Chicago to find a Loggerhead Shrike or Prairie-Chicken. Additionally, the booklet contains spring arrival dates for every species each year from 1913 to 1920.

A small yellow, white, and dark blue bird specimen with a handwritten tag tied to its leg

Nathan Leopold collected this Kirtland's Warbler specimen in Oscoda, Michigan, in 1923.

Joshua Engel

Colin Sanborn's reply to Leopold must have been disappointing. He writes on November 20, 1950: "Your group of Kirtland's Warblers were never photographed and in fact have never been on exhibition." Sanborn goes on to write about his own activities in a breezy, newsy tone: birding, giving talks to a local ornithological society, etc. In other words, no mention of the fact that he's writing to infamous prisoner #9306-D. 

Leopold spent 33 years in prison until his parole in 1958. Active in the Natural History Society of Puerto Rico, Leopold traveled throughout the island for bird watching, and in 1963, he published Checklist of Birds of Puerto Rico and the Virgin Islands. He died of natural causes in Puerto Rico in 1971 at the age of 66.

As for the Kirtland's Warblers—happily, they are making a comeback. According to Engel, "The species has made an incredible comeback, from a low of about 200 singing males in the early 1970s to over 2,000 today. It's likely to be removed from the endangered species list in the next few years."

A version of this post was originally published on the Biodiversity Heritage Library's blog.