Observations of whooping cranes during winter aerial surveys: 1950 - 2011.

The Aransas-Wood Buffalo population of whooping cranes (Grus americana) declined to near extinction by the 1940s. Starting during winter 1950 - 1951, annual aerial surveys were conducted to observe and record the number of whooping cranes wintering on Aransas National Wildlife Refuge (NWR) and surrounding areas. This effort resulted in 38,332 observations of whooping crane groups being marked on paper maps between winter 1950 - 1951 and winter 2010 - 2011. We digitized those locations by matching the ArcMap 10 screen display as close as possible with the paper maps and approximating points in each of the marked locations. These data are freely available to the public. However, we caution that these data have quality issues and limitations due to, but not limited to, inconsistencies and lack of documentation on how data was collected, reliance on perceived knowledge of unmarked birds' identities, and inaccuracies introduced during both recording and digitization. We request that proper credit to the compilers of this dataset is explicitly included in any work using these data. For more information refer to the document entitled "Observations of Whooping Cranes During Winter Aerial Surveys: 1950-2011." We request that proper credit to the compilers of this dataset is explicitly included in any work using these data.