Treatment groups of ducks were exposed to different virus doses (2, 4, 6 log10 50% egg infectious doses) and by different routes (contact or intrachoanal). The experimental setting was a laboratory with animal care as approved by the institutional animal care and use committee as appropriate for the species and age of bird. Data are the virus titers shed by the oral and cloacal route for individual mallard ducks exposed to H5N1 highly pathogenic avian influenza virus by day post exposure. Samples were collected through 11 days post exposure. Virus titer equivalents were determined by quantitative real-time RT-PCR. Serological data are serum antibody titers to the challenge virus as determined by hemagglutination inhibition assay (reciprocal of the log2 dilution) determined with serum collected 10 or 11 days post exposure. Resources in this dataset:Resource Title: Virus_shed_data. File Name: Spackman_et_al_virus_shedData from H5_mallard_study_2022.csvResource Description: Virus shed data determined by quantitative real-time RT-PCRResource Title: Serology data for H5 challenged mallards. File Name: Spackman_et_al_Serology_Data from H5_mallard_study_2022.csvResource Description: Serology determined by hemagglutination inhibition assay. NS= no serum (sample not run)