To Tweeters and obol,

In response to Al Jaramimllo's comment on species concepts. I believe
too little weight is placed on the normal range of individual and
sub-population variation in any species population. Also, there are
behavioral and song traits that involve a significant learned component.
Behavioral differences in foraging behaviors, for example, may simple
reflect a more generalized "optimal foraging strategy" that will yield
contrastive behavioral norms under contrasting ecological conditions.
Vocal patterns are in my opinion far more complex than is usually
recognized. Crows have a large repertoire of calls and exhibit
considerable individual variation. To say that two populations "sound
different" requires, I believe, more than an impressionistic assessment,
but a clear appreciation of how vocalizations vary with situational
factors and allometric correlations as well as "dialects" governed by
learned traditions. Thus much variation may eventually be attributable
to other than genetic isolation.

gene Hunn.

On Wed, 2 Mar 1994 Alvaro Patricio Jaramillo <jaramill at sfu.ca> wrote:
> Cc: obol at gaia.ucs.orst.edu
>
> On: Tue, 1 Mar 1994 Eugene Hunn <hunn at u.washington.edu> wrote:
> >
> > Al,
> >
> > I agree on the towhees but feel the crow situation may have more in
> > common with song sparrows, juncos, flickers, etc. I have long urged
> > someone at the University to find a student wishing to do a thesis on the
> > questions. The obvious starting point would be a systematic analysis of
> > vocalizations.
> >
> > Gene Hunn.
> >
>
> I am really surprised that the NW Crow question has not been tackled
> by any one of the DNA gurus, or has it and I don't know about it. The
> question of how much geographical variation is "too much" for a single
> species, such as the three that you mention has always bothered me. A
> big problem is that the data are confounded by all sorts of variables, one
> of which is the misuse of the subspecies concept. Birds like the Song
> Sparrow, Savannah Sparrow, Red-winged Blackbird and lots of others have
> been over split into way too many subspecies. Much of the variation in
> these forms is clinal, not dissected into smaller, identifiable populations.
> At the same time I feel as if some good species may have been overlumped
> within these highly variable species. My version of a good species is kind
> of a mix between the biological and phylogenetic, not very satisfying, and
> only a personal opinion. Hybridization does not bother me, especially when
> it is rare. Hybrid zones, where most or all of the individual birds are
> hybrids, also does not bother me, as long as the zone is relatively stable
> and narrow. Deciding on what narrow actually means is subjective. If we
> consider Kumlien's Gull to be a hybrid zone between the L.g.glaucoides and
> Thayer's Gull, then the zone is too wide, but it may not be in Western/
> Glaucous-wing. My opinion would be to keep Glaucous-wing and Western as
> separate species but lump the Iceland complex. Similarly, I would split the
> Orioles, Towhees, etc. Some other groups are much more complex, for example,
> the Juncos. By applying my loose hybrid zone criterion, I would split off
> White-winged, and Grey-headed, keep Oregon and Slate-colored together (assuming
> that J.h.cismontanus is actually a hybrid swarm), and I don't know about
> Pink-sided since I have little knowledge about its range and interaction with
> the other forms but I have a feeling that it would be split off. BTW, in my
> undergraduate years I did a phenetic analysis of Juncos, based on skeletal
> measurements. I was extremely surprised at the fact that while White-winged
> Junco is similar to Slate-colored in plumage, it is incredibly different in
> skeletal morphometrics: they are huge, short-winged and long-legged if I
> remember correctly. There is a general size cline in Oregon/Slate-colored,
> but Pink-sided is bigger than either of them. As well, White-winged Junco X
> Pink-sided Junco hybrids are very rare, I recall that less than five are known.
>
> Bird populations that are isolated from each other, and show differences in
> two data sets (i.e. plumage, song characteristics, behavioural characteristics,
> genetic data) I would split off. If they only differ in one type of characteristic I would hold off. So I would split Belding's Sparrow from Savannah, Northern
> from southern Sharp-tailed Sparrow, split the Fox Sparrow. As you can see,
> it would be a mess if they allowed me in the AOU checklist committee, don't
> worry it will not happen. I enjoy the topic of species concepts, and I am
> merely thinking out loud hoping to incite some discussion. In general, I
> think that species concepts are really a tool. You choose the one that will
> answer the question that you are interested in. Perhaps birders should take
> hold of this idea and create a "Birding species concept", if you can ID it
> then you can count it! How does that sound?
>
> Al Jaramillo
> jaramill at sfu.ca
> Vancouver, B.C.
>
>
>
>