Mistletoe Tyrannulet Zimmerius parvus

  • Order: Passeriformes
  • Family: Tyrannidae
  • Monotypic
  • Authors: Andrew W. Jones

Diet and Foraging


Mistletoe Tyrannulet consumes both insects (including beetles and other small insects, and spiders) and fruits, with mistletoe drupes (Loranthaceae) making up a large part of the diet (Stiles and Skutch 1989).

A study of drupe consumption on mistletoes (Oryctanthus occidentalis) in Panama showed that the majority of fruits were consumed by mistletoe specialists: 62% by Yellow-crowned Tyrannulet (Tyrannulus elatus) and 11% by Mistletoe Tyrannulet. The remainder of the fruit was consumed by a generalist, Ochre-bellied Flycatcher Mionectes oleagineus (20.4%), and by two opportunists, Rusty-margined Flycatcher Myiozetetes cayanensis (1%), and Social Flycatcher Myiozetetes similis (5.6%) (Watson 2013). Interestingly, this study showed that the narrow diet of these mistletoe specialists means that they spend a long time foraging with a population of mistletoes; they process and regurgitate the seeds quite quickly, so their value to the mistletoe as a seed disperser is actually lower than that of the generalists that only occasionally feed upon mistletoes.

Foraging Behavior

Mistletoe Tyrannulet captures invertebrate prey by gleaning; fruit are consumed by gleaning or by hovering in front of fruit clusters (Skutch 1960, 1997). This species forages at all levels of the forest, but primarily in the middle and high canopy. Focused observations on mistletoes showed that individuals feed throughout the day, and approach a tree with a population of mistletoes from a consistent direction, and depart in another consistent direction, suggesting that they may be trap-liners (Watson 2013). Tyrannulets test the ripeness of drupes with the beak before selecting them (Watson 2013).

Recommended Citation

Jones, A. W. (2018). Mistletoe Tyrannulet (Zimmerius parvus), version 2.0. In Neotropical Birds Online (T. S. Schulenberg, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/nb.paltyr3.02