This bird has sung loudly for an hour or more every morning and sporadically throughout the day during winter and spring 2017-18, from conspicuous perches in the front yards of houses across the street from my house on the Stanford campus. My guess is that it is an unmated male, attempting to attract a mate. California Thrashers are sedentary, highly territorial, and they mate for life. Both sexes sing the strikingly extended and variable imitative song, and can do so at any time during the year.