Blue-crowned Motmot (Momotus momota) - HBW 6, p. 283

Taxonomy: Ramphastos momota Linnaeus, 1766, Cayenne.
Quite closely related to M. aequatorialis, and sometimes treated as conspecific, but significant differences in size and plumage, as well as ecological differences, almost certainly justify their being ranked as separate full species. Very wide distribution and considerable geographical, as well as individual, variation have led to numerous races being named; situation complex, however, and taxonomic revision needed. Races goldmani, exiguus and lessonii sometimes referred to as “lessonii group”, conexus, subrufescens, spatha and osgoodi as “subrufescens group”, and all other populations E & S from NC Colombia as “momota group”; these groups, along with coeruliceps, sometimes thought possibly to represent four separate species; in particular, populations in E Panama differ from those in W in several plumage characters, as well as in size and, apparently, voice, with no recorded intergradation, suggesting they are possibly distinct species; also, isolated Trinidad and Tobago race bahamensis rather distinct, would probably be considered separate species on basis of molecular genetics. Populations of E Panama and NW Colombia, described as race reconditus, now included in conexus. Twenty subspecies currently recognized.