Fig. 4. Summary of wintering and breeding distributions of species that breed across both hemispheres in the Holarctic, but winter at least in part in the Americas; one species (Larus ridibundus) ranges considerably farther south in Russia, extending to areas that have indeed seen HP-H5N1 outbreaks. Color ramp indicates numbers of species (white = 0, darkest shade = 5 species). From Peterson et al. (2007).