Seventeen-year-old David Tönnessen and two of his younger brothers, Jonathan and Judah, watched a never before seen in Colorado Tropical Kingbird at the far end of the banding station woods on 17 September 2017. As the name implies, this flycatcher is primarily a tropical species, breeding in the U.S. only in SE Arizona and the Lower Rio Grande Valley of Texas. Its full breeding range extends south through Mexico, all of Central America and west of the Andes to central Peru and east of the Andes, south to central Argentina. Some of the distinguishing characteristics that separate this tropical tyrant-flycatcher from its more northern congeners, especially Western Kingbird and Cassin’s Kingbird are its large bill and long, slightly notched tail.
It is a very common bird in most of its range and easy to find as it perches in the open often on wires or exposed to view on the top of tall trees. Compared to other flycatchers, it has a specialized diet, primarily chasing large insects in flight. It will eat fruits as well which might explain why the Colorado bird was seen in a fruiting Russian olive tree.
Very impressive was that David also obtained a recording of its unique vocalization and quite distinct from its two more expected relatives’ call notes. The vocalization was then converted to a sonogram and now there is no doubt as to its identity. The photograph of the bird above is a Tropical Kingbird occurring in San Blas, Mexico. Unfortunately only the three brothers saw the Chico bird before it flew to the west.