Steve and others, This is really interesting. However, to me, citing a lack of evidence of hybridization has 2 major problems. 1) hybridization is a rare event and would be incredibly difficult to detect in "species" that are largely inseparable morphologically and 2) how could hybridization occur, let alone be documented in two "taxa" that are not genetically different in any way??
It sounds like the information BNA is using is largely out of date, presumably gathered at a time well before rigorous phylogenetic work was done on these critters. Here is the citation for the relatively recent (2008) phylogenetic paper I was referring to: Marthinsen, Gunnhild, Liv Wennerberg, and Jan T. Lifjeld. "Low support for separate species within the redpoll complex (Carduelis flammea–hornemanni–cabaret) from analyses of mtDNA and microsatellite markers." *Molecular Phylogenetics and Evolution* 47.3 (2008): 1005-1017. Enjoy, folks can pm me if they are interested in getting ahold of a copy of the paper. andy boyce missoula, mt On Sunday, January 6, 2013 2:55:36 AM UTC-7, Steven Mlodinow wrote: > > Greetings All > > The following is rather technical, and is taken from the Birds of North > America Online, a website worth subscribing to. Note that repeated attempts > to demonstrate hybridization have failed. As I recall, mtDNA differences > between Darwin's Finches are essentially nil, though I am not certain of > this. > > Hoary Redpoll closely related to Common Redpoll and sometimes treated as > conspecific under latter name (e.g., Salomonsen > 1928<http://bna.birds.cornell.edu/bna/species/544/articles/species/544/biblio/bib056> > , > 1951<http://bna.birds.cornell.edu/bna/species/544/articles/species/544/biblio/bib057> > ; Williamson > 1961<http://bna.birds.cornell.edu/bna/species/544/articles/species/544/biblio/bib076> > ; Troy > 1985<http://bna.birds.cornell.edu/bna/species/544/articles/species/544/biblio/bib065>) > > or as separate species (e.g., Baldwin > 1968<http://bna.birds.cornell.edu/bna/species/544/articles/species/544/biblio/bib006> > , Godfrey > 1986<http://bna.birds.cornell.edu/bna/species/544/articles/species/544/biblio/bib025>). > > Extensive sympatry of *C. h. exilipes*with nominate *C. f. flammea* much > debated, less so equally interesting overlap of *C. h. hornemanni* and *C. > f. rostrata* . In areas of sympatry, birds range in plumage from typical > pale of Hoary Redpoll to typical dark of Common Redpoll, which has led to > frequent unsubstantiated claims that intermediates are hybrids (e.g., Brooks > 1968<http://bna.birds.cornell.edu/bna/species/544/articles/species/544/biblio/bib013> > , Jehl and Smith > 1970<http://bna.birds.cornell.edu/bna/species/544/articles/species/544/biblio/bib031>). > > Plumage of both Hoary and Common redpoll varies and dark Hoary (often young > or female) can be mistaken for pale (often older male) Common Redpoll. > Little or no direct evidence of hybridization. Differences between Hoary > and Common redpolls in time of arrival and departure at breeding grounds, > relative abundance from year to year, habitats, diets, calls, physiology, > behavior, size, and appearance suggest best treated as separate species > (Molau > 1985<http://bna.birds.cornell.edu/bna/species/544/articles/species/544/biblio/bib044> > ; Knox > 1988<http://bna.birds.cornell.edu/bna/species/544/articles/species/544/biblio/bib036> > ; Herremans > 1990<http://bna.birds.cornell.edu/bna/species/544/articles/species/544/biblio/bib028>; > > Seutin et al. > 1992<http://bna.birds.cornell.edu/bna/species/544/articles/species/544/biblio/bib059> > , > 1993<http://bna.birds.cornell.edu/bna/species/544/articles/species/544/biblio/bib060>). > > Suggestion that *C. h. exilipes* and nominate *C. h. hornemanni* are > northern representatives of, and most closely related to, nominate *C. f. > flammea* and *C. f. rostrata*, respectively (Molau > 1985<http://bna.birds.cornell.edu/bna/species/544/articles/species/544/biblio/bib044>), > > and that these 4 taxa be treated as separate species (Herremans > 1990<http://bna.birds.cornell.edu/bna/species/544/articles/species/544/biblio/bib028>), > > requires further support. See also Brooks > 1917<http://bna.birds.cornell.edu/bna/species/544/articles/species/544/biblio/bib012> > . > > *C. f. flammea* arrives on breeding grounds later than *C. h. exilipes* and > leaves earlier in autumn. The 2 forms sometimes nest in different habitats > but may forage in same areas. Some authors have reported differences in > diets. The 2 taxa differ in calls, physiology, behavior (e.g., migration), > size, and appearance. Abundance of the 2 forms in any 1 breeding place > varies independently from year to year. Widespread sympatry, but no direct > evidence of interbreeding, despite claims otherwise (e.g., Salomonsen > 1928<http://bna.birds.cornell.edu/bna/species/543/articles/species/543/biblio/bib128> > , > 1951<http://bna.birds.cornell.edu/bna/species/543/articles/species/543/biblio/bib129> > ,Williamson > 1961<http://bna.birds.cornell.edu/bna/species/543/articles/species/543/biblio/bib161> > , Harris et al. > 1965<http://bna.birds.cornell.edu/bna/species/543/articles/species/543/biblio/bib061> > , Troy > 1985<http://bna.birds.cornell.edu/bna/species/543/articles/species/543/biblio/bib149>). > > “Intermediate” phenotypes show part of normal range of plumage variation in > *C. f. flammea* and *C. h. exilipes* (Molau > 1985<http://bna.birds.cornell.edu/bna/species/543/articles/species/543/biblio/bib094> > ; Knox > 1988<http://bna.birds.cornell.edu/bna/species/543/articles/species/543/biblio/bib080> > ; Herremans > 1990<http://bna.birds.cornell.edu/bna/species/543/articles/species/543/biblio/bib065> > ; > > Steven Mlodinow > Longmont CO > -- You received this message because you are subscribed to the Google Groups "Colorado Birds" group. 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