Foreign game bird liberations in the U.S., 1960-1978
These data were obtained by digitizing data from U.S. government reports on releases of foreign game bird. Records on 628 introductions of ring-necked pheasants in the United States between 1960 and 1978 were compiled. This data was used in the 2006 publication: Drake, J.M. 2006. Heterosis, the catapult effect, and establishment success of a colonizing bird. Biology Letters 2:304-307. doi:10.1098/rsbl.2006.0459 .
I compiled records of 628 introductions of ring-necked pheasants in the United States between 1960 and 1978 including information about the success or failure of the population to establish, propagule pressure and whether survival or reproduction was observed after release.
A measure of annual propagule pressure was obtained for each introduction record by dividing the total number of individuals introduced by the number of years over which introductions occurred (usually, but not always, 1) and transforming to a log scale. Propagule pressure (the logarithm of the number of individuals introduced) was included as a covariate because it is a wellknown correlate of introduction success and has confounded interpretation of previous analyses. Dependent variables (generally qualitative observations) were scored as: (i) evidence of survival (binary response), (ii) evidence of reproduction (binary response) and (iii) evidence of establishment (ordered response: 0, failed'; 1, 'probably failed'; 2, 'probably established'; 3, 'established'; see text 2 of electronic supplementary material for details). As there was strong evidence of establishment (responseZ3) for only seven populations, records were grouped, resulting in 179 introductions that 'failed' or 'probably failed' and 128 introductions that 'established' or 'probably established'.