The validity of the three currently recognized subspecies of White-throated Flycatcher is based entirely on the examination of a handful of specimens, which show considerable individual variation due to wear, fading, or foxing (Monroe 1968). The Nicaraguan population is adjacent to the Honduran population yet is currently classified with the Costa Rican and western Panama population, from which it is separated by approximately 250 km of lowlands (Nicaraguan Depression). A larger set of measurements is necessary to determine the validity of subspecific divisions.
Some sources suggest that lowland records from the southern part of the range may pertain to northern migrants, although there is (as yet?) no evidence to support this.
The breeding range needs to be better defined, and the conservation status of White-throated Flycatcher may be in need of revision, as the total population estimate of > 50,000 individuals, accepted by BirdLife International (2018), is almost certainly too high.