Jürgen Haffer, a member of the AOU since 1964 and a Fellow since 1970, died in Essen, Germany, on 9 April 2010. He was born in Berlin on 9 December 1932, the fourth child of Dr. Oskar Haffer, a high school biology and mathematics teacher, and his wife Margarete. His father stimulated his early interest in birds. These were later intensified by his high school teacher Gerhard Wichler, who not only took him on early-morning birdwatching tours in East Prussia but also gave him his first book on birds. At the age of 13, Jürgen finally became imprinted on birds when he reported a ringed bird to the Zoological Institute in Berlin. Erwin Stresemann himself talked with the boy and introduced him to bird banding. This meeting initiated a long friendship between Stresemann and Haffer. Jürgen became a student at the University of Göttingen in 1951, moved to the University of Freiburg in 1953 for a year, and concluded his geology, paleontology, and biology studies with a doctoral thesis on a paleontological-morphological topic in Göttingen in 1957.
After university, Jürgen, already well read on Amazonia, immediately accepted a job offer from the Mobil Oil Company to do geological mapping studies in northern Colombia. While still in Germany, he prepared himself to study certain bird groups, with an emphasis on subspecies and species limits. In Bogotá, he exchanged many letters with Stresemann and Ernst Mayr, who gave him advice and suggestions and discussed his ideas. His geological-paleontological training proved useful in his ornithological work. Large parts of Colombia and Amazonia were little known then, and he undertook many expeditions on mules and in dugouts into these uncharted regions. Sometimes cut off from the outer world, Jürgen gained a rather complete overview of the geological make-up of South America in general, and the northern Andes in particular. This also benefited his ornithological work.
The data and insights gained in the 10 years of field work in Colombia led to a new theory of speciation in Amazonia. Jürgen recognized that the Andean uplift could not have fashioned the Amazonian avifauna directly, and set out to explain Amazonian diversification by way of changes in the vegetation caused by Pleistocene climatic fluctuations. According to his very influential refugial hypothesis, bird populations were isolated in forest remnants during dry periods, diverged in isolation, then formed subspecies or species when Amazonia was completely covered by forest during wetter climatic conditions. Jürgen also recognized the special role of rivers as barriers in this process.
These results were published in Science (165:131–137, 1969) as “Speciation in Amazonian forest birds.” The work became one of the foundations of modern Neotropical biogeography. Ernst Mayr praised it as “the finest work in recent years on bird speciation,” and it has been cited more than 600 times. It still stirs up discussions among evolutionary biologists and biogeographers. Researchers successfully expanded Jürgen's ideas to other groups of organisms and found, among other things, that climate change in the Miocene may have contributed to Amazonian diversity as well.
Later professional assignments led Jürgen to the United States and Iran, where he worked on various problems in speciation and biogeography. He returned to Germany in 1977, mainly so that his Colombian-born children could complete their schooling in Germany. After further assignments to Egypt and Norway, he retired at the age of 55. Over a period of 20 years, he contributed systematic sections to the Handbook of Central European Birds by Urs Glutz von Blotzheim und Kurt Bauer. After retirement, Jürgen's focus shifted to the history of ornithology. He became interested in the question of how schools of thought emerge, for example how notions like the species concept developed.
He summarized his numerous papers in that field in a plenary lecture at the 2006 International Ornithological Congress in Hamburg. He became a leading expert in the history of ornithology and evolutionary biology. He particularly emphasized the role of Central European science in these fields. He did not falter in stressing the role of what he called the “Stresemann revolution,” which turned German ornithology from a purely systematic and faunistic discipline into a modern integrative-biological one that incorporated reproductive biology, ecology, physiology, functional morphology, and the study of behavior well before that transition occurred in Anglo-American ornithology.
The intensive interactions with both Stresemann and Mayr, with whom he exchanged letters weekly, ultimately allowed Jürgen to produce biographies of both of these eminent scientists whom he admired so much. Ornithologenbriefe des 20: Jahrhunderts, a thousand-page collection of historical letters written by ornithologists of the 20th century, appeared in 1997. It was intended to document the contributions of continental European science to the synthetic theory of evolution. Together with Erich Rutschke and Klaus Wunderlich, he published biographies of Stresemann (2000) and Mayr (Ornithology, Evolution, and Philosophy—The Life and Science of Ernst Mayr; 2007). These three volumes are important contributions to the history of ornithology, and they also bear witness to Jürgen's enormous determination and productivity, and his ability to focus on the important aspects of a problem. At one point, he mentioned Mayr's self-confidence, photographic memory, ability to synthesize ideas from various sources, and never-ending enthusiasm. These virtues, together with physical prowess at advanced age, describe Jürgen as well.
One needed to exercise care when presenting one's ideas to Jürgen Haffer, because he would quickly come up with appropriate critical questions and brilliant interpretations of his own. It is astonishing to realize that Jürgen was actually not a professional, but an amateur ornithologist. In this capacity he was an honorary member of the German Ornithologists' Society (DO-G), the Neotropical Ornithological Society, and the Linnaean Society of New York. He received the AOU's Brewster Award in 1975.
The continuous support of his family explains much of Jürgen's productivity. His wife shared his interest in Amazonia. They met in Bogotá, where she worked as a teacher in the German school. Both traveled to Amazonia each year, even after they had finally settled in Germany. Not long after his last visit to Amazonia in 2009, he succumbed to a short and severe illness.
Jürgen was warm hearted, witty, and ready to help. Listening to his tales about his many adventures in the field and encounters with famous ornithologists will remain in the memory of those who had the good fortune to know him.