A cloudy afternoon at the Rio Aquiares near the hamlet of El Banco began very quietly but proved quite productive in the end. At the present time, in what is not yet the rainy season, the river is easily fordable and flows through a broad valley that contains some side streams and boggy land.

The Olive-crowned Yellowthroat (Geothlypis semiflava) is a common bird in the Caribbean lowlands and yet I find myself now reporting it for only the third time ever. One landed in the mist nets at CATIE, Turrialba, during bird-banding back in 2010, and then in December 2015 we saw a pair up close not far from El Copal on the Cartago Christmas Bird Count. Today, on the Rio Aquiares, I found a pair fairly close to home for the first time.

Male Olive-crowned Yellowthroat, photographed earlier this year near La Suiza de Turrialba by  John Beer

Yellowthroats  are bigger than most other warblers. They are generally found down fairly low, often in wet fields, and there are four species here in Costa Rica, all termed Geothlypis.  In the Turrialba area, only two are easily found.  As regards the two others, visitors from North America will be largely uninterested in the Common Yellowthroat (Geothlypis trichas), with which they are very familiar but which in any case is mostly an uncommon passage migrant in Costa Rica. I have not recorded this species in our area. The other one, the Masked Yellowthroat (G. aequinoctalis), is restricted to a small area near San Vito close to the Panamanian border.

The two species to be considered in our area are the generally common Gray-crowned Yellowthroat (G. poliocephala) and the subject of this post, the Olive-crowned Yellowthroat (G. semiflava), whose male has a black mask with no border. Females are difficult to distinguish but, fortunately, males are likely to be present.

Here’s the Gray-crowned in another of John’s photos for comparison purposes:

Male Gray-crowned Yellowthroat at Aquiares in July 2016; note that the black face mask is small in comparison with the Olive-crowned.

The Rio Aquiares visit lasted two hours and was very pleasurable even though no other unexpected species occurred. I had excellent views of several aquatic species such as Sunbittern and Spotted Sandpiper. My list can be found at the following eBird Central America link: http://ebird.org/ebird/camerica/view/checklist/S32407723