Suddenly, about four days ago, the Phainopeplas vanished!
A male Phainopepla brings mistletoe berries to his young.
(Pen-and-ink by Narca)
Phainopeplas belong to an interesting New World group of birds, the silky flycatchers. Only four species are in this tropical family, all of them lovely, and of those only the Phainopepla's range extends north into the US. Most are crested, with silky plumage. Phainopeplas perform eye-catching displays of aerial flycatching. They have ruby-red eyes and white wing patches, and they feast on the small berries of mistletoe (Phorandendron), algerita (Berberis), Lycium, and juniper.
More than 100 years ago, Gilman noticed their remarkable dual life: they appear in the Sonoran Desert in late winter or early spring, and breed there. As the heat intensifies, they then retreat with their fledglings to their cooler canyon fastness in Arizona and California, where breeding again commences in late spring or early summer. Whether the same individuals breed twice each year remains a mystery not yet completely decoded.
Miyoko Coco Chu (dissertation from UC Berkeley 1999) attempted to unravel the complexities of the birds' breeding and seasonal movements in California, where they move between the Colorado and Mojave Deserts, and the coast range. (Thanks to Carl Lundblad for bringing Chu's work to my attention!)
Phainopeplas are suspected to practice "itinerant breeding," like the infamous Red-billed Queleas of Africa. It is a very rare strategy among birds, and seems to occur when their food supplies are unpredictable and shift geographically in response to dramatic changes in local conditions.
Other itinerant breeders include Tricolored Blackbird and, it is speculated, the extinct Passenger Pigeon.
Both Phainopeplas and queleas specialize on foods that can shift dramatically during the breeding season, and both are regularly faced with the prospect of complete failure of their nesting efforts, due to drought and other vagaries. These undependable conditions very likely foster unusually flexible behavior, and Phainopeplas appear able to remain reproductive even when forced to abandon their early season breeding habitat in the low desert. Once they leave for the cooler canyons of desert mountain ranges, they may be able to bring off a second brood, or to attempt another clutch if the first one failed in the desert.
Here in southeast Arizona, by the time the Phainopeplas return to the canyons, the summer monsoons (in a good year) have brought good rains, allowing the food shrubs to produce berries for another generation of Phainopeplas.
So, our birds in Portal just left this past week. Has anyone in the low desert noticed an influx of Phainopeplas?
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Nice post. "Fastness" was a new word for me. I haven't noticed an influx in the Tucson area at all, by the way. Did you know the extinct Mohoidae family from Hawaii – five species once thought to be part of the Old World Meliphagidae – are now considered close relatives of the silky-flycatchers?
ReplyDeleteI actually did have my first ever (3 months) Phainopepla from my yard yesterday, but he did not stay and I haven't noticed any elsewhere. Thanks for the post, these birds are fascinating!
ReplyDeleteRich, that's fascinating that an ancestral silky flycatcher made it all the way to Hawaii! The current species, other than Phainopeplas, are so rarely recorded as vagrants.
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