Figure. Maximum-likelihood phylogenetic trees showing inferred relationships among nucleotide sequences for the complete coding regions of gene segments for influenza A virus strain A/northern pintail/Alaska/UGAI16–3997/2016(H8N4) (white circle indicated with an arrow) and reference sequences from viruses isolated from birds in Eurasia (black circles) and North America (white circles). Bootstrap support values for continentally affiliated clades are shown. Phylogenetic trees with complete strain names as tip labels are provided in the online Technical Appendix Figure (https://wwwnc.cdc.gov/EID/article/24/10/18-0447-Techap1.pdf). H, hemagglutinin; M, matrix; N, neuraminidase; NP, nucleoprotein; NS, nonstructural; PA, polymerase acidic; PB, polymerase basic.