Lazuli Bunting is a vibrant songster of western riparian corridors, chaparral, and forest edges. The western cousin of Indigo Bunting, the do hybridize at times where their rages overlap on the western Great Plains. They winter in flocks in weedy areas in western Mexico and the southern Baja Peninsula.
The northward passage can be seen as they stream north through Arizona and in to California and the Rocky Mountains. Its arrival is rather sudden, and while they can be expected in the more temperature areas of California a bit before they can be in inland areas, their arrival is not nearly as divided as in other western species, like Western Tanager and Swainson’s Hawk. The breeding range is shown well and the timing of the migration is quite accurate.
Watch how the fall departure shows concentration in the Mojave Desert, where birders carefully check oases and migrant traps for this and other species of western (and eastern) migrants. They probably aren’t spread evenly in this area, but the strong bias of birder data from oases (and the very small patch size of these oases) makes it hard for the model to distinguish the important characteristics that define the causes for high concentrations . These types of biases are hard to overcome and will be a research challenge in the future. It will need to be solved statistically, since emploring birders to do hundreds of random counts in birdless salt flats of Death Valley may be a tough sell! that said, counts like that (even ones with no birds!) are always appreciated!