--- In capecodbirds@yahoogroups.com, "jabisla" <jabisla@...> wrote:
>
> Mt friend Matt recently asked me about the Great White Heron seen in
Fairhaven. He had been told that the Great White Heron is a morph of the Great
Blue Heron, and that confused him.
>
> I tried to explain, with my limited knowledge base, that Great Egrets are in
the same genus as Great Blue Herons, but are not the same species. I told him
that the Great White is actually the same species as the Great Blue, just a
different "morph." I told him (I thought but am not sure) that "morphs" are
permanent for that bird. I tried to think of another local and common bird that
has such "morphs," and couldn't. I gave the example of subspecies, while noting
that this is something different.
>
> So, my questions are,
> 1. What is a "morph"?
> 2. How is that different from a subspecies?
> 3. Are "morphs" in fact permanent (as in, is a Great White Heron always a
Great White?)? Are Great White chicks born to Great White parents?
> 4. Are there other examples of a common local bird (or any bird) that has such
"morphs"?
> 5. Is there an evolutionary function to "morphs," or is this just the entropy
of evolution?
>
> Thank you for your help,
> John Abisla
> Falmouth
>
Hi John,
In my Eastern Region, Audubon Society Field Guide to North American birds, it
refers to a Great White Heron as a white phase of the Great Blue Heron that
occur mainly in the Florida and Caribbean region. In the book it also says that
both white and dark have been found in a single nest even though the Great White
Heron was considered a distinct species at one time. I am not a professional
birder, however I was photographing a Great Blue Heron yesterday and had the
book open to read while I was looking at my photos and I saw this question. It
will be interesting to see what other more experienced birders have to say. Hope
this helps a tad.