Successful nesting by Curve-billed Thrashers ( Toxostoma curvirostre ) using American Kestrel ( Falco sparverius ) nest boxes

Curve-billed Thrashers (Toxostoma curvirostre) typically build cup nests of small twigs and sticks in low growing shrubs, cacti, and trees. Nesting in cavities or human-made structures has been rarely reported for the species. From 2021 to 2025, a pair of Curve-billed Thrashers nested in one of several American Kestrel (Falco sparverius) nest boxes that I monitor in Lubbock, Texas. In 2025, two additional nest boxes were in use by Curve-billed Thrashers. I monitored the 2025 nests and found two successfully fledged nestlings and a third was likely successful. Although other species have been documented using kestrel nest boxes, I found no published references noting such behavior for Curve-billed Thrashers, and very few documentations of their use of cavities. To my knowledge, this is the first documentation of Curve-billed Thrashers successfully using nest boxes.