#1 Supporting Information for Mussmann et al.: Cover letter as PDF _____________________________ #2 Supporting Information for Mussmann et al.: "Genetic Rescue, the Greater Prairie Chicken, and the Problem of Conservation-Reliance in the Anthropocene" Parts of this SI (as PDF): A. Thirty six-year history of Greater Prairie Chicken translocations in Illinois B. Details of methodology and results C. References for supporting information - Figures S1-S2 - Tables S1-S4

A central question in conservation is how best to manage biodiversity, despite human domination of global processes (=Anthropocene). Common responses (i.e. translocations, genetic rescue) forestall potential extirpations, yet have an uncertain duration. A textbook example is greater prairie chicken (GRPC: <i>Tympanuchus cupido pinnatus</i>), where translocations (1992–1998) seemingly rescued genetically depauperate Illinois populations. We re-evaluated this situation after two decades by genotyping 21 microsatellite loci from 1831 shed feathers across six leks in two counties over 4 years (2010–13) and found only 88 unique male genotypes. Low migration rates (less than 1%) established each county as demographically independent, but with declining-population estimates (4 year average <i>N</i> = 79). Leks were genetically similar and significantly bottlenecked, with low effective population sizes (average <i>N</i><sub>e</sub> = 13.1; 4 year <i>N</i><sub>e</sub>/<i>N</i> = 0.166). Twelve significantly different family groups, with <i>r</i> = 0.31 > half-sib <i>r</i> = 0.25, defined genetic structure. Average heterozygosity, indicating short-term survival, did not differ among contemporary, pre- and post-translocated populations, whereas allelic diversity did. Our results, the natural history of GRPC (i.e. few leks, male dominance hierarchies) and its controlled immigration suggest demographic expansion rather than genetic rescue. Legal protection under the endangered species act (ESA) may enhance recovery, but could exacerbate political–economic concerns on how best to manage ‘conservation-reliant’ species, for which GRPC is now an exemplar.