In spring of 2022 a major high pathogenic avian influenza outbreak caused widespread observations of dead and symptomatic birds in North America, including on the Yukon Delta during the nesting season. Observations of sick and dead birds were collected during the nest distance sampling survey using the same distance sampling protocol so that an estimate of the number of bird carcasses could be produced. This is the main quality controlled data set for dead and sick birds recorded during the survey and used for the distance sampling analysis and population estimates. It is produced from the code in wrangle_2022.R and contains information on on carcass location, distance from transect, species, observer, and other covariates. For distance sampling analysis, it needs to be combined with the transect effort data in Effort_2022.csv. See the file wrangle_2022.R for details on quality control process.
