Above is a video that I've made about Crissal Thrasher.Only the males sing. I'd love to study their song structure, by recording  comparing the repertoire of different singing males. I have recorded individual males singing for more than  7 continuous  minutes. In Shoshone,  it seems that only one male sings the Anna's Hummingbird attack call, another the Virginia Rail, a third copies the Pacific Chorus Tree Frogs which sing in springtime along the Shoshone Wetlands. To photograph or film a Crissal Thrasher is extremely difficult because of their preference for thick Mesquite. The deeper and darker and thornier the better has been my experience. I am very fortunate to have been able to observe Crissal Thrasher year round in Shoshone, CA. There are over a dozen pairs here on the birding trails.The singing begins in January and continues is some cases into at least August. 
           While filming singing Crissal Thrashers, the most difficult part is to get close to the singer without interrupting or flushing him. Every step forward runs the risk.