GPS Tracking Reveals Rare ‘Itinerant Breeding’ Behavior in California Bird.

Reproduction and migration are the two most demanding tasks in a bird’s life, and the vast majority of species separate them into different times of the year. Only two bird species have been shown to undertake what scientists call “itinerant breeding”: nesting in one area, migrating to another region, and nesting again there within the same year, to take advantage of shifting food resources.