All captive birds in the experiment gained substantial mass over the course of the study, with an increase of about 46% from the pre-inoculation to the late post-inoculation periods (figure 2). The visible subcutaneous fat stores of these birds increased significantly from pre-inoculation until the early post-inoculation period (t = 7.71) and increased somewhat further during the late post-inoculation period (electronic supplementary material, figure S1 and table S1). The pectoral muscle size also increased over these periods, but this muscle score only statistically differed between late post-inoculation and the pre-inoculation stages (t = 3.46).