Guatemalan Tyrannulet

The Guatemalan tyrannulet, or paltry tyrannulet, (Zimmerius vilissimus) is a very small passerine bird in the family Tyrannidae, the tyrant flycatchers. It is found in Belize, El Salvador, Guatemala, and Mexico. == Taxonomy and systematics == The Guatemalan tyrannulet was originally described as Elainia vilissima. During much of the twentieth century it and several other tyrannulets were placed in genus Tyranniscus but a study published in 1977 erected the present genus Zimmerius for them. Zimmerius vilissimus was previously called the paltry tyrannulet and included as subspecies what are now the mistletoe tyrannulet (Z. parvus), spectacled tyrannulet (Z. improbus), and Venezuelan tyrannulet (Z. petersi). Taxonomic systems began separating them in 2004 but it took until 2020 for all to complete the change. Most systems adopted the common name Guatemalan tyrannulet for Z. vilissimus sensu stricto to avoid confusion with the previous multi-subspecies paltry tyrannulet but as of late 2024 BirdLife International's Handbook of the Birds of the World retained the old "paltry" name. The Guatemalan tyrannulet is monotypic. == Description == The Guatemalan tyrannulet is 10 to 12 cm (3.9 to 4.7 in) long. The sexes have the same plumage. Adults have a grayish crown and a short whitish supercilium. Their…