During the mid-twentieth century, Soviet scientists developed the “natural focus” theory–practice framework to explain outbreaks of diseases endemic to wild animals and transmitted to humans. Focusing on parasitologist-physician Evgeny N. Pavlovsky and other field scientists’ work in the Soviet borderlands, this article explores how the natural focus framework’s concepts and practices were entangled in political as well as material ecologies of knowledge and practice. We argue that the very definition of endemic plague incorporated both hands-on materialist experience and ideological concepts (...) that supported Soviet colonization. Theorizing and fighting plague assisted with the goals of controlling and improving landscapes and peoples in southern Russia and Central Asia. The history of the natural focus framework illustrates how Soviet disease ecology co-developed with the needs of local and central political powers in the Soviet borderlands. (shrink)

Wildlife populations in the northern reaches of the globe have long been observed to fluctuate or cycle periodically, with dramatic increases followed by catastrophic crashes. Focusing on the early work of Charles S. Elton, this article analyzes how investigations into population cycles shaped the development of Anglo-American animal ecology during the 1920s–1930s. Population cycling revealed patterns that challenged ideas about the “balance” of nature; stimulated efforts to quantify population data; and brought animal ecology into conversation with intellectual debates about natural (...) selection. Elton used the problem of understanding wildlife population cycles to explore a central tension in ecological thought: the relative influences of local conditions (food supply, predation) and universal forces (such as climate change and natural selection) in regulating wild animal populations. He also sought patronage and built research practices and the influential Bureau of Animal Population around questions of population regulation during the 1930s. Focusing on disease as a local population regulator that could interact with global climatic influences, Elton facilitated an interdisciplinary and population-based approach in early animal ecology. Elton created a network of epidemiologists, conservationists, pathologists and mathematicians, who contributed to population cycle research. I argue that, although these people often remained peripheral to ecology, their ideas shaped the young discipline. Particularly important were the concepts of abundance, density, and disease; and the interactions between these factors and natural selection. However, Elton’s reliance on density dependence unwittingly helped set up conditions conducive to the development of controversies in animal ecology in later years. While ecologists did not come to consensus on the ultimate causes of population cycles, this phenomenon was an important early catalyst for the development of theory and practice in animal ecology. (shrink)