We continue to have about the same number of Cassin's (we regularly flocks of 20-30) both at the feeder and in the forest at the base of the Collegiate Peaks here in the BV-Salida area that have been present most of the winter. The Ponderosa cone crop was/is heavy here. So the "Boulder invasion" doesn't seem to have come from here; the idea that this was a migrant push from further south is an interesting idea. Sally Waterhouse Nathrop
On Thursday, April 16, 2020 at 2:45:27 PM UTC-6, Richard Trinkner wrote: > > I'd be very interested in theories to explain this spring's dramatic > Cassin's Finch invasion of the lower elevations of the Front Range. We > usually get these prolific snow storms in March and April, but my 24 years > of personal records don't show anything previously like this year's > Cassin's Finch invasion. (Of course, 24 years is a tiny data window for a > species that probably predates humans...) > > Are cone crops in the high country poor this year? Are the finches coming > from northern latitudes? Was last year a banner breeding year? Why is the > weather disproportionately affecting this particular high-elevation finch > species? > > I don't have any answers myself, but hope that others might. > > Cheers, > > Richard Trinkner > Boulder > -- You received this message because you are subscribed to the Google Groups "Colorado Birds" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/cobirds/206f848c-6c2e-43e1-9598-1c9ff0b7b54a%40googlegroups.com.
