With the arrival of the first migrant Red-eyed vireo (Vireo olivaceus) yesterday morning I take the opportunity to write a quick post about our vireos as well as about the latest trends in the birds here in San Antonio de Santa Cruz de Turrialba. First, regarding migrants, the vireo was high in a zorrillo tree together with a Black-and-white warbler, which seems to always be the first migrant to arrive here each year. The only other migrant species I have found so far has been a wood pee-wee. Both Eastern and Western occur here, and this one, perched by don Martin’s cabin, was probably a Western wood-pewee (Contupus sordidulus) since the bill seemed almost completely dark. As has often been the case, it refused to give an identifying call note. It consistently returned to the same perch. According to the literature, the two contupus species should be the very first northern migrants to arrive, starting in July, but I have never found one before September. Our resident Tropical pewee, which does not consistently return to the same perch, usually gives a trilling call and is generally distinguished by some very pale yellow on the belly, if you get a good look. I have not seen or heard one for at least two months, however.
At first light, the Rufous-tailed hummingbirds are singing their high-pitched twitter and chasing away the Green-breasted mango from the feeder. The White-necked jacobins have already done their mysterious end-of-year disappearing act. A bright day is beginning made all the more so by the absence of the recently fallen higuerón and pine-tree on the bottom fence-line. This now gives a much wider view down to the distant Talamanca mountain range. The garden is already filling in nicely where the pine fell. Noisiest birds this morning are the Gray-capped flycatchers and the Clay-colored thrushes, sounding their alarm notes. The Orange-billed nightingale-thrush has not called now for at least two weeks.
There have been no recent sightings of either the tiger-heron or the sunbittern down on the river and the Piratic flycatchers (southern migrants) are long gone, despite the suggestions in the bird guides that they may stay until late September. Another noticeable absentee is the Grayish saltator, usually fairly regular here, while the Bare-shanked screech-owl has not called since the big trees fell.
On a positive note, the Slaty spinetail is now always a possibility in the tangled undergrowth near the patio, and fairly large flocks of White-collared swifts have appeared in front of each approaching rain shower. Their acrobatic flight is a joy to watch, especially when they swoop low. If viewed against a suitable background, the white collar is clearly visible. On one occasion, a flock of a smaller swift species appeared. They seemed too large to be Vaux’s swifts, the only other species that I have identified here at home so far. On the basis of size, the most likely candidates are the Black swift (Cypseloides niger) and the White-chinned swift (Cypseloides cryptus) but I was unable to get a really good look because of their rapid flight. Swifts are notoriously difficult to identify with certainty. The tail on these birds did not always appear notched, even if I assume they were all of the same species. The Black swift seems to be much the more common of the two.
And finally, a few words about our vireos. The Yellow-green vireo (Vireo flavoviridis) nests here (in our eucalyptus, for example) and then migrates south, some staying in Costa Rica until late October [Garrigues]. I last saw a pair on September 15th and I am very familiar with the slow, cheerful phrases of its song. The Brown- capped vireo (Vireo leucophrys) is a resident species that ought to be found here, but so far I have found it only when visiting friends in San Ramon in the north. The picture above of the Red-eyed vireo was taken here and is by courtesy of friend and house-sitter Stephanie DeLaGarza (should be DelVireo, I suppose). It is slightly commoner than the Yellow-throated vireo (Vireo flavifrons),which is easily identified by its yellow spectacles and upper breast. Here’s a rather blurry shot taken in the garden a while back.
I have only one confirmed sighting in San Antonio of the only other likely vireo in our area, the Philadelphia vireo (Vireo philadelphicus), though I may have missed it among the numerous Tennessee warblers that arrive in migration. I’ll be looking out for it starting late October.