Date: 9/18/25 4:24 pm From: ed pandolfino via groups.io <erpfromca...> Subject: Re: [centralvalleybirds] Ruby-crowned Kinglets
Amy (and others who may be interested),
First, Ruby-crowned Kinglets used to be (early last century) a relatively common breeder in the Sierra. However, they are now uncommon and very sparsely distributed there (while still VERY common in the Rockies). It is likely that ALL Ruby-crowned Kinglet populations are migratory (most long-distance, some mainly altitudinal).
From fall through early spring, this kinglet is VERY common in the lower elevations of CA. However, based on some work we did on song dialects (https://journal.afonet.org/vol94/iss3/art10) it appears that all the CA winterers breed in central Alaska! We don't know where the Sierra breeders winter, but probably somewhere in Mexico.
Ed PandolfinoSacramento
On Thursday, September 18, 2025 at 01:11:42 PM PDT, Amy Williamson via groups.io <amywillbird...> wrote:
Over several days' stationary observations at the same location at about 6200' in the Sierra Nevada (Nevada Co, very close to the border with Placer Co) I've heard/seen a single Ruby-crowned Kinglet.
Despite being a long time birder, without an ornithology background there are many gaping holes in my knowledge of bird populations. Based on my geographical locations in CA and on the southeastern US coast, I think of Ruby-crowned Kinglets as ubiquitous wintering birds and I recognize how they look, sound and behave as they forage. That's the extent of my knowledge.
Seeing/hearing only one Ruby-crowned over several days has sparked my curiosity. I looked up their range and found breeding range in the Sierra Nevada.
Now I wonder whether this lone bird is part of fall migration or not. Do "we" know much about how many and at what elevation these birds breed here? Do we know if the breeding population here are residents or if they, too, are migrants from elsewhere, whether far or near?
Amy WilliamsonNevada Co (currently)
