Figure 4.

Phylogenetic relationship of sequences from the N8 subtype. North American isolates of northern pintails from Alaska (Koehler et al. 2008) and California (this study) are indicated with black circles. North American reference samples taken from GenBank are shown with a black triangle. Four equine reference samples serve as an outgroup. Bayesian posterior probabilities and levels of neighbor-joining bootstrap support >70% between major clades are shown on branches. Numbered vertical bars delineate major clades.