Date: 3/30/17 9:57 am From: Wayne Hoffman <whoffman...> Subject: [obol] Re: Young Golden Crowns?
Fred sent me a photo of his bird. It had lost its tail, presumably to a predator, which is what made him think fledgling. This time of year, first-cycle birds (hatched in 2016) are difficult to tell from winter adults, but his appeared to be first-cycle - information I sent to him privately.
On 3/29/2017 10:42:39 PM, Dan Gleason <dan-gleason...> wrote:
When Fred Ramsey suspected a young Golden-crowned Sparrow earlier, I sent him the following information.
Breeding of Golden-crowned Sparrow anywhere in the lower 48 is almost unheard of. The breeding range is much further north, in the Yukon and central Alaska. The breeding habitat there (typically scrub-tundra and some mixed conifers) is also unlike our local habitats. Adults don't typically arrive on breeding grounds until May and egg dates are mid-May to mid-June, so this would be very early. Unlike many species, there has been no documented change in range of this species, although there is still much to learn about Golden-crowned Sparrows. To date, I only know of one study dedicated to breeding biology of this sparrow and it was published in 1987. There are some scattered summer records of Golden-crowned Sparrows in the US (outside of Alaska), even one from Florida, but these are all wandering individuals out of range, not breeding birds.
Fred's bird was not a juvenile, but a young adult still mostly in non-breeding plumage. I suspect you are seeing the same. Full adult breeding plumage is often not reached until late April.
Owner, Wild Birds Unlimited of Eugene
Ornithology Instructor, University of Oregon