A Tool for Assessing Impacts on Health

Edward McSweegan
1999 BioScience  
The attempt at "Quantifying Threats to Imperiled Species in the United States" (BioScience 48: 607-615), by David S. Wilcove and colleagues, is a timely reminder of the importance of Natural Heritage Programs and systematic data on plant and animal populations. Last July, it was our privilege to reexamine an area studied by Arthur Cleveland Bent and colleagues in 1905-1906 and reported on in The Auk (1907)(1908). Unfortunately, these early explorers were so intent on documenting occurrence that
more » ... ing occurrence that they neglected the task of assessing numbers in specific habitats. After describing the landscape in his 1907 account, titled "Summer Birds of Southwestern Saskatchewan," Bent wrote: "With this brief description of the three classes of plains, which in the aggregate comprised fully 95 percent of the whole region, we will leave this comparatively uninteresting phase of the subject and consider some of the more highly favored localities which we found much richer in bird life and therefore of much greater interest ornithologically" (Bent et al. 1907) . The favored localities were the stream bottoms and prairie "lakes." Unfortunately, that "less interesting" 95 % of the region is now mostly devoted to agriculture, and we can only guess at that land conversion's impact on bird life. We found the contrasts striking. Wherever the prai-QUANTIFYING SPECIES-A LOST OPPORTUNITY pp., illus. $75.00(cloth).
doi:10.2307/1313531 fatcat:325pug5qlvgo5oyk6z4pgklo3q