Mistletoe Tyrannulet

The mistletoe tyrannulet is about 9.5 to 10 cm (3.7 to 3.9 in) long and weighs about 8.5 to 10 g (0.30 to 0.35 oz). The sexes have the same plumage. Adults have a grayish crown and a short but wide whitish supercilium. Their upperparts are olive green. Their wings and tail are mostly olive green with yellow edges on the wing coverts, flight feathers, and tail feathers. Their underparts are mostly off-white with faint darker streaks on the breast and sometimes a pale yellow wash on the belly and undertail coverts. Both sexes have a highly variably grayish white to grayish brown iris, a short dusky gray or black maxilla, a gray or black mandible with a dusky or brownish base, and dusky gray or blackish legs and feet. Immature birds have brown irides, an olive gray crown, a yellow tinge to the supercilium, and wider but less distinct yellow edges on the wing feathers than adults.

The mistletoe tyrannulet is found from far eastern Guatemala and far southern Belize east and south on the Caribbean sides of Honduras and Nicaragua and most of Costa Rica and Panama slightly into extreme northwestern Colombia's Antioquia and Chocó departments. It inhabits the tropical to lower temperate zones, in the interior and edges of evergreen forest both open and fairly dense. It also inhabits secondary forest, pastures and fields with scattered trees and shrubs, and gardens. It favors areas with mistletoes (Loranthaceae). In elevation it ranges from sea level to 1,400 m (4,600 ft) in Honduras, to 1,200 m (3,900 ft) in Nicaragua, to treeline at 3,000 m (9,800 ft) in Costa Rica, and to 2,300 m (7,500 ft) in Colombia.

The mistletoe tyrannulet feeds on mistletoe berries, other fruits, insects, and spiders. It is an active forager, moving quickly about with its tail cocked as it searches for food. It forages singly or in pairs, at all levels of the forest but mostly from the forest mid-story to the canopy. It takes arthropods by gleaning while perched and fruit by gleaning and by briefly hovering at clusters. At least in Panama it joins mixed-species feeding flocks.