- Tiaris olivaceus
Identification
Length: 10.0-10.7 cm; weight: 9.5-10.0 g
- Conical bill, sharper than that of the related seedeaters
Adult male
- Olive-green back
- Black face and breast
- Bright yellow throat, supercilium, and lower eyelid spot
- Greyish-olive underparts
Adult female
- Dull olive-green upperparts
- Paler grey underparts
- Dark breast smudges may be visible
- The face pattern is much weaker and duller, and may be almost invisible
Young birds: duller and greyer than the female
Young males: begin to acquire full adult plumage in their first year.
Distribution
Central and South America and the Caribbean
Caribbean (West Indies): Cuba, Cayman Islands, Jamaica, Hispaniola, Haiti, Dominican Republic and Puerto Rico
Central America: Mexico, Guatemala, El Salvador, Honduras, Nicaragua, Costa Rica, Panama,
South America: Colombia, Venezuela and Ecuador
Introduced to Hawaii.

Photo by Stanley Jones
Road to Rincon de la Vieja towards Dos Rios, Guanacaste Province, Costa Rica, November 2011
Taxonomy
Subspecies
There are 5 subspecies[1]:
- T. o. pusillus:
- T. o. intermedius:
- Cozumel Island and Holbox Island (off Yucatan Peninsula)
- T. o. ravidus:
- Isla Coiba (Panama)
- T. o. olivaceus:
- T. o. bryanti:
The scientific name has been spelled olivacea in the past.
Habitat
Rain forest, open grassy areas, woodlands and grassland. Observed at heights around 275 meters.
Behaviour
Diet
They feed mainly on seeds (mostly grass), berries and some insects.
Breeding
The female builds the globular nest, which is formed from stems of grass and weeds. They sometimes nest in loose colonies. The clutch consists of two or three brown-speckled white eggs, which are incubated by the female alone for 12-14 days to hatching.
Vocalisation
Call: a weak buzzing trilled ttttt-tee
The male vibrates his wings as he sings to the female from only a few centimetres away.
References
- Clements, J. F., T. S. Schulenberg, M. J. Iliff, S. M. Billerman, T. A. Fredericks, B. L. Sullivan, and C. L. Wood. 2019. The eBird/Clements Checklist of Birds of the World: v2019. Downloaded from http://www.birds.cornell.edu/clementschecklist/download/
- Raffaele, H, J Wiley, OH Garrido, A Keith, JI Raffaele. 2003. Birds of the West Indies. Princeton: Princeton Univ. Press. ISBN 978-0691113197
- Torok, M. and K. J. Burns (2020). Yellow-faced Grassquit (Tiaris olivaceus), version 1.0. In Birds of the World (T. S. Schulenberg, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.yefgra1.01
Recommended Citation
- BirdForum Opus contributors. (2023) Yellow-faced Grassquit. In: BirdForum, the forum for wild birds and birding. Retrieved 5 December 2023 from https://www.birdforum.net/opus/Yellow-faced_Grassquit
External Links
GSearch checked for 2020 platform.1