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 cobirds+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/cobirds/206f848c-6c2e-43e1-9598-1c9ff0b7b54a%40googlegroups.com.
