Fig. 9: Partial dependence and individual conditional expectation of different meteorological factors on the number of wild birds HPAI-H5 infections.
From: Assessing HPAI-H5 transmission risk across wild bird migratory flyways in the United States

There is a nonlinear association between meteorological factors and avian influenza. The X axis represents the values of the corresponding meteorological factors, and the Y axis represents the number of wild bird infections. PDSI is the Palmer Drought Severity Index, PMDI is the Palmer Modified Drought Index, and PZI is the Palmer Z-Index.