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Spatial History Lab: Conference Poster; Created 4 August 2009
Critical Habitat

A Spatial History of Extinction and Reintroduction
Jon Christensen 1 & Gabriel Shields-Estrada 2
1. Stanford University, History Department
2. Stanford University, Spatial History Lab, Research Assistant
In the 1960s, Paul Ehrlich and a group of scientists sought to turn a butterfly that lives in small remnant patches of native California grasslands into a model system for population biology, at the same time that Ehrlich was making population the global issue of the times. Ehrlich succeeded on both scales. Although the population bomb was controversial, population and consumption remain core concerns. And Ehrlich and his colleagues did turn the Bay checkerspot butterfly into a model system, out of which grew important developments in population ecology, conservation biology, and the first habitat conservation plans. But while they studied the checkerspot and turned its habitat on Jasper Ridge in the hills above the Stanford University campus In California into a biological preserve, the butterfly went extinct locally, and their efforts to protect it may have been one of the causes. Politics and science are entwined, and the history we know and tell shapes conservation efforts for better or worse. In this case, the history that was constructed to justify protection, and elimination of grazing from not only Jasper Ridge, but other areas, may have limited the scope of conservation and restoration across a wider landscape, and contributed to the demise of the butterfly. This history goes back to 18th and 19th century data sources to re-examine the 20th century narrative of the transformation of California's grasslands and how that history shaped modern conservation. By conceiving of conservation as necessary to protect relict spaces where time seemed to have stopped, opportunities were foregone for conservation across a more heterogeneous, ever-changing landscape. And efforts to protect places like Jasper Ridge from change and disturbance, such as grazing, were the final nail in the coffin for important populations of this threatened species. But it is not too late. While the clock of history cannot be turned back, and some opportunities are lost forever, we may recover and realize future opportunities for conservation by better understanding the importance of history not just for understanding but also shaping environmental changes in space and time.
Figure 1. Bay checkerspot butterfly
A Model Species
This research grew out of a multidisciplinary team studying the feasibility of reintroducing the Bay checkerspot butterfly, a threatened species, to Jasper Ridge Biological Preserve in the coast range foothills on the Stanford campus, where it disappeared in 1998. Paul Ehrlich found this butterfly on Jasper Ridge and in the early 1960s turned it into a model species for population biology — like the fruitfly is for genetics — at the same time that he was writing The Population Bomb. The checkerspot research became a landmark in conservation biology, while scientists watched the butterfly’s populations go up and down and eventually go extinct locally.
Figure 2. Visualization of Jasper Ridge Bay Checkerspot Populations
Visualizing Extinction
Using field records of lepidopterists, scientific publications, natural history museum specimens, environmental impact statements, and federal records associated with the Endangered Species Act, I have constructed a comparative history of more than 50 populations of the Bay checkerspot since the early 1960s. Using a Geographic Information System database and visualization software programs designed by the Spatial History Lab at Stanford, I have analyzed and shown that two-thirds of the populations have gone extinct during this period. But while half of those populations have disappeared because their habitat was developed, the other half disappeared in parks and protected areas. The most likely cause of their demise is habitat change. And the most likely cause of habitat change was removal of grazing. Bay checkerspot populations survive on private lands that continue to be grazed.
Figure 3. Visualization of Extinctions of the Bay Checkerspot
Narratives and Data
The history that has been told about the transformation of California’s grasslands by cattle and their portmanteau biota of annual grasses seems to have contributed to the demise of the Bay checkerspot butterfly. This history conceived of spaces where the butterfly and the native plants that it depends on survived as refuges from history. Thus ecologists conceived of these spaces as places that needed to be protected from change and disturbance. Spatial data derived from observations and narratives complicated this history.
Figure 4. Grazing Increases Probability of Survival
Experimenting with Reintroduction
As a result, we have now recommended an experimental reintroduction of the Bay checkerspot butterfly at Jasper Ridge Biological Preserve. This, however, challenges the conception of the preserve as a space in which changes in nature can simply be studied rather than managed. Instead, the preserve is now considering how best to study management of a changing environment and species on the move through carefully designed experiments.
Figure 5. Jasper Ridge Biological Preserve
Making Environmental History Practical
Environmental history does not provide a baseline to which we can return. We cannot rewind the clock of environmental change. But history can contribute to a practical conversation about our present and future prospects in a changing environment. These conversations are most productive in a multidisciplinary context, in which a historical perspective can open narratives and data to new questions, new combinations, the creation of new knowledge, and perhaps even the recovery of possibilities once thought lost.
End Notes
This paper was originally presented as a poster at the first World Congress of Environmental History in Copenhagen on 4 August 2009.

Author Information Correspondence and requests for materials should be addressed to Jon Christensen

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