Dusky-capped Flycatcher – A first island record
November 28, 2020
The waning hours of sunlight and reduced numbers of migrant landbirds signals another fall migration is coming to an end on the Farallon Islands. But even though the fall crew is preparing to leave the islands in a week, migrants are still turning up!
While research assistant Mike Mahoney was taking down mist-nets to be put away for next year, he spotted a Myiarchus flycatcher (a large genus of flycatchers with very similar plumages) in Twitville’s tree mallow (Malva arborea). A quick radio message brought the entire crew hurrying over to comb the area for this bird. Heading over to the nearby Heligoland Monterey pine (a magnet for birds as it is one of only three trees on the island), we quickly resighted this relatively small bird with a crested, dark brown head, bright yellow belly, indistinct wing bars, and a dark tail.
In addition to its smaller size and other subtle plumage differences, one particularly useful feature in definitively separating this suspected Dusky-capped Flycatcher (a vagrant from Latin America) from the more geographically plausible Ash-throated Flycatcher is the extent and distribution of rufous in the tail.
As the bird flitted amongst the rocks and boulders from Heligoland to the Rabbit Cave Catacombs, the underside of the tail did not appear to have any rufous coloration. Staff biologist Jim Tietz, with camera at the ready, captured an image of the bird in flight with its tail spread – no rufous on the underside of the tail. The bird was conclusively identified as a Dusky-capped Flycatcher (Myiarchus tuberculifer), making it the only confirmed record for the island. However, a previous record on October 24, 2004, was rejected by the California Bird Records Committee for insufficient documentation.
Thankfully the bird remained on the island for three more days until the winds calmed down and we were able to catch it and band it. The measurements confirmed that the bird was smaller than any other Myiarchus flycatcher that has occurred in California.
Dusky-capped Flycatchers are widespread in Central and South America, but in the United States they are mostly confined to breeding in the oak–pine canyons of southeastern Arizona and southwestern New Mexico. While they are not commonly seen outside their limited breeding range in the U.S., the species has been recorded as far north as British Colombia in 2016. Once considered extremely rare in California, numbers of records in the state increased dramatically after the 1980’s as identification criteria became more refined and numbers of birdwatchers increased. Regardless, this Dusky-capped Flycatcher is an exceptional find, and hopefully, not the last rare bird of the fall!