Four days of scrambling up and down wet forested slopes on Puerto Rico. Nasal, piercing calls of Bicknell’s Thrush emanating from my small, handheld speaker. Ears on high alert for at least a muted response. Many miles logged from the western mountains of Maricao to the eastern ridges of Carite State Forest. No Bicknell’s Thrush, not yet anyway, but…angels appeared.
Elfin Woods Warbler (Setophaga angelae) is one of Puerto Rico’s 17 endemic birds, second in rarity only to the nearly extirpated Puerto Rican Parrot (now recovering thanks to captive breeding). This mountain-dwelling gem is a rare, elusive find — it wasn’t even a described species until 1972, and there are believed to be fewer than 2,000 individuals on the island. Superficially resembling its North American counterparts, Black-and-white and Cerulean warbler, the Elfin Woods-Warbler (EWWA) primarily inhabits the stunted, wind-clipped forests of Puerto Rico’s highest elevations. Its subtle, thin song and calls challenge auditory detection by birders and ornithologists alike (I can personally attest to that…).
VCE’s advance field team of José Salguero, Julio Salgado and I managed to hit the Elfin Woods Warbler jackpot on January 22, our very first morning of Bicknell’s Thrush surveys. We found 9 birds in a large, mostly intact patch of “subtropical wet serpentine forest“ (José’s classification), not exactly the species’ classic elfin habitat, but an area of rich floristic and avian diversity. Needless to say, this birder chalked up a lifer, plus a few other new endemics, including Puerto Rican Screech Owl, Puerto Rican Emerald, Green Mango, Puerto Rican Tody, Puerto Rican Vireo, and Puerto Rican Tanager. However, angels carried the day for me, hands-down.
Oh, and that other bird, Bicknell’s Thrush? Honestly, I was surprised not to find it in some of the forest patches we surveyed, which had the key ingredients of wet broadleaf forest with a moderately dense understory. We only formally surveyed 4 sites, and our minimum target for the winter is 60. I fully expect that José and Julio will encounter birds in multiple locations, but I’m guessing they won’t unearth the motherlode that we know exists on Hispaniola. For sure, VCE couldn’t have two more capable ornithologists scouring the island. We’ll report their findings in the weeks ahead.