Date: 7/9/18 11:12 am From: Wayne Hoffman <whoffman...> Subject: [obol] Re: Lawrence's Goldfinch
This seems to be following the classic pattern of a bird expanding its range poleward - "accidental" occurrences at long intervals, followed fairly abruptly by a spate of more frequent occurrences, and then evidence of "residency" such as territorial singing, longer stays, occurrences of multiples, in this case breeding. I think if we examined the early records of Anna's Hummingbirds, Black Phoebes, Red-shouldered Hawks, Elegant Terns, Brown Boobies, White-winged Doves, etc. we would see some notable similarities.
it's important to realize that in general, range expansions are driven as much by stuff going on in the source areas as by stuff happening in the new areas. Obviously, for species to become established, the habitat needs to be suitable, but the immigrants did not come because of the habitat quality - they came because they were getting crowded st home, or summers were getting too hot or too dry, etc. [Black-throated Sparrows are more common in the northern parts of their range in drought years in their core range.]
Range expansions of native birds in continental habitats seldom result from a single "dispersal event" followed by proliferation of those initial colonists. Instead they are fueled by a pattern of straying/migration from the historic species range. Results vary for island colonizations and for exotics like Eurasian Collared-Doves, Starlings, and House Sparrows.
Back to Lawrence's Goldfinches: It would be great to get photos of this family, to make sure the female is also a Lawrence's. It would not shock me to see a lone male Lawrence's playing house with a female Lesser, or even American, goldfinch. - Following the Stephen Stills rule: If you're not with the one you love...
On 7/9/2018 9:32:52 AM, Alan Contreras <acontrer56...> wrote:
Recent years have had multiple reports but this is first breeding I know of. Of course I don’t know everything.
I apologize if this posts twice. Tried to send from my iPad and it isn't working.
Where: At the Provolt Pond in Josephine County. Intersection of Williams Highway and Highway 238. Just north of the "Welcome to Josephine County" line. Large shrub with a branch overhanging the pond. Sitting on the branch.
What: Five Lawrence's Goldfinches. Four babies, begging, and one beautifully marked adult male. Black face, bright yellow chest with gray/white belly, gray back. Very distinct. Babies were fairly plain, unmarked face, faded streaking on flanks fading to to no markings in center of belly, yellow on outer wings, stout-ish bill.