The search for rare butterflies in the high mountains is not really a science, nor does it require too much technical mountaineering skill, and although it has many elements of both, it is mostly a path of extreme patience, more akin to the metaphysical aspects of meditation, than to anything else”. --John Hessler, “Searching for the Rarest Butterflies in the Alps”, 2025.

Biography

Spending most of my time hiking in the Alps, filming jellyfish in the waters of the French Riviera or searching for endangered butterflies in some remote valley, I am a historical biogeographer, lepidopterist, and writer, in Nice, France.

My current projects center on using historical and archival natural history collections, to reconstruct the collecting travels of Vladimir Nabokov in the Alps and the Pyrenees, and tracing the locations of the collections and identifying the collectors who participated in publishing the monumental Biologio Centrali-Americana.

Wondering about the changes and causes of butterfly population distributions over time, I am also studying the historic distribution patterns of the critically endangered large blue butterfly, Maculinea arion, across Europe and the United Kingdom, from preserved museum specimens.

For the last few seasons, my field oriented biogeographic research has centered on mapping the intricate spatial distribution patterns of rare forms of high-altitude butterflies in the Pyrenees, and in the remote valleys of the parc national du Mercantour and the parc national des Écrins.

Fascinated by the rare phenomenon of butterfly bioacoustics production, the lab is working on Maculinea-Myrmica butterfly-ant interactions and mimicry, and on the sound productions of Aglais io, the European peacock butterfly, using wavelet and signal processing techniques.

I am the author of more than one hundred articles, books, and reviews, including the New York Times bestseller and NPR selection, MAP: Exploring the World. My latest papers, Mapping the Last Pool of Darkness: a Tribute to Cartographer Tim Robinson (1935-2020), recently appeared in the Journal of the Washington Map Society and, In Nabokov’s Net: searching for his butterflies in the mountains of the Ariège was published in the Nabokov Journal, in early 2025.

An avid alpinist I am a frequent contributor to many climbing publications, like Alpinist Magazine, and the Himalayan Journal, where I have written stories on the history mountaineering in the alps, on the structure and mapping of glaciers, and even on Petrarch’s ascent of Mont Ventoux.

A Fellow of the Royal Geographical Society (FRGS), I find wondering what it is like to be a butterfly, pondering the mysterious history of Colias ponteni, and marvelling at the complexity and beauty to be found in Darwin’s tangled bank, strangely comforting.

I currently live in Nice, France.