Not so Common Yellowthroat

Our morning visit to the trail at Casa Turire brought views of at least 19 species that need an aquatic environment plus a wide variety of woodland birds. One of the highlights, however, was the Common Yellowthroat (Geothrypis trichas), a species I know well from my days in Dallas, Texas. I well remember finding one of these little beauties among reeds in one of the harshest of north Texas winters.

Male Common Yellowthroat atop the water hyacynth at Angostura Dam

When I first moved to Costa Rica, I assumed from a glance at the mapped distributions for the various species of Yellowthroat that the Common Yellowthroat would be the most commonly found species. Not so! Indeed, in my immediate area I have not found a single one in almost 10 years. Of course, as North American birders well know, this species requires suitable habitat that consists of reeds or similar wet areas near lakes and ponds. This does exist hereabouts but is met with much more frequently at lower elevations closer to Turrialba, predominantly around the Angostura Dam.

In Costa Rica the Common Yellowthroat, distinguished from the others in the male by the clean white border above the black face mask, is both a passage migrant and an uncommon winter resident. In the case of the bird(s) that Larry and I found at Casa Turire, we have (a) winter resident(s) since migratory passage is between mid-October and November and, on the return journey, between April and early May. The bird guides state that winter residents tend to be single birds but we’re hoping that the pic below will confirm that the female was also present. Both pictures were taken at the same location but matters were complicated by the presence of at least one Mourning Warbler (Geothlypis philadelphia), another North American migrant whose females and immatures are not always easy to distinguish (for me, at least!) from the three Costa Rican Yellowthroats, Masked, Gray-crowned and Olive-crowned. However, as you can see, our bird here has very little yellow below, while the aforementioned species have mostly yellow underparts.