Now that you've had a chance to look at the new version
of our checklist (see Wings Over Dutchess, January 2004),
you know that the most obvious change is in the placement
of the Waterfowl and Gallinaceous Birds before Loons. But
upon closer inspection, you may have noticed a couple of
name changes as well. The Common Snipe has become Wilson's
Snipe and our beloved Rock Dove is now a Rock Pigeon.
In Part 1, we talked about checklist
order and its relationship to taxonomy. In Part 2,
we'll address species name changes and why they occur. By
way of review,
on our checklist we follow the taxonomic order and nomenclature set forth by
the American Ornithologists' Union (AOU), which is generally regarded as the
authority for North and Central America. In other countries and on other
continents, there are similar bodies that determine species order and naming.
in England there is the British Ornithologists' Union (BOU). Although these
groups cooperate, they are independent of each other, and thus we find differences
some common names found on their checklists. For example, we have Loons
the British have Divers—but on any continent ornithologists know this order
of birds as Gaviiformes.
Ornithologists are well served by scientific
names and have no real need for the common names that birders
use in their
communications. But imagine what fun
it would be to learn and use only scientific names! Because of the obvious
difficulties this would present to the vast majority of birders, and to facilitate
in general, official common names are set forth by the AOU and similar authorities
elsewhere in the world. Once a name is decided, it is generally permanent,
but sometimes names are changed. While many name changes are easily explained
accepted by birders, others may raise an eyebrow here or there. Why, you
may ask, do names have to change when they work perfectly well? What was
Snipe"? And why did "Rock Dove" have to change to "Rock Pigeon"?
We spend years learning all these names and then they change! "Solitary
Vireo" was just fine, but a while back the AOU decided to change that one
to "Blue-headed Vireo." The examples seem endless.
Sometimes, a new name is simply deemed
to be more appropriate than the existing
one. This is the case with "Rock Pigeon." This species
really is more of a pigeon than a dove. So it makes more sense to call
better reflects the relationship between this species and others that are similar.
A Rock Pigeon is much more like a Band-tailed Pigeon (which can be found in the
western US) than it is like a Mourning Dove. The AOU made the change for
this reason, and to conform to the same name change that had already been made
In many cases, however, the new name
is the result of a "lump" or a "split." As
ornithologists study birds, they sometimes decide that the taxonomy needs to
be modified in order to clarify or correct a species' (or several species') status.
A fundamental issue in this regard is the meaning of the word "species." This
subject is fraught with lively debate and is far from settled. Simplistic definitions
have fallen far short, and opinions differ on the criteria required to establish
independent species status. At one time, two animals were considered to
be of the same species if they bred with each other and produced offspring that
reproduce. But any intermediate birder can cite examples in which two different
species hybridize successfully. In truth, the concept of "species" is
a human invention, something that makes it easier for us to classify the creatures
and understand the world around us. However, the unstoppable march of evolution
will always blur the lines between certain species and force humans to reconsider
previous taxonomic decisions. Even if perfectly executed, a taxonomy represents
no more than a snapshot in time. So we are back to our evolving checklist
its sequence changes, lumps, and splits.
Lumps and splits occur when species
definitions are determined to be incorrect. Sometimes
two distinct species are found to be so closely related that
actually only one species. In this case, the two species are "lumped" together
and given a single species name. In other cases, what was thought to be
a single species is found to contain two or more populations that are sufficiently
from each other that they each merit distinct species status. When taxonomists
make this kind of change, it is known as a "split." In recent
splits have been more frequent than lumps.
Looking at our recent checklist changes,
Wilson's Snipe got a new name because Common Snipe (Gallinago
split into two distinct species. The newly
designated Wilson's Snipe (Gallinago delicata) is the American bird, while
Snipe (Gallingo gallinago) is its Eurasian counterpart. Interestingly,
these two birds were listed as separate species years ago, were later lumped
as Common Snipe, and now have been split again. The same thing happened
with one of our colorful local birds. Years ago, there was a western species
Oriole" and an eastern species called "Baltimore Oriole." Then
they were lumped into one species, Northern Oriole. More recently, Northern
Oriole was re-split into Bullock's and Baltimore! Getting back to our Solitary
we now call it Blue-headed Vireo in our area because the species was split three
ways, into Blue-headed, Plumbeous, and Cassin's Vireos. Take a look at
field guide and compare these three.
If you keep a life list, you probably
like hearing about species splits, because they can sometimes
get you a
new life bird in an instant. Many American birders
who had traveled in Europe, for example, gained a lifer when Common Snipe was
split, because they now learned that they had seen a different species in Europe
from the one they had seen in the U.S. On the other hand, sometimes we
just have to take our lumps and lose a lifer when two species
on our list are determined
to be one!
Most birders take these changes in stride. Others
simply ignore them. Still others are vocal in their
protest, saying that the authorities are in cahoots
field guide publishers, who regularly churn out new editions in response
to taxonomic and naming changes. Some organizations
have recommended that their
be left alone until the dust settles. But one thing is certain: After
the dust settles, it will eventually be stirred up again.
To me, all this change is exciting. It
reflects progress and learning, the result of scinetists'
to gain new knowledge of the world
Some taxonomic changes are made on the basis of morphological, geographic,
vocalization, and other studies. At the same time, new methods of
DNA analysis represent a
major contributing factor in the taxonomic upheavals that have taken place
during the past decade or so. Learning about the latest changes gives
us a better understanding
of the scientific process and of the progress that ornithologists make
as they learn more and more about our feathered friends.
References & Resources
American Ornithologists' Union. The AOU Check-list
of North American Birds, 7th edition, as modified by 42nd,
43rd & 44th
Clements, James (2000) Birds of the World, a Checklist, 5th
ed. Ibis Publishing Company.
Charles Sibley and Burt Monroe, Jr. (1991) Distribution
and Taxonomy of Birds of the World. Yale University Press.
On the web:
American Ornithologists' Union (2003). Online
AOU Check-list of North American Birds, 7th edition,
as modified by 42nd, 43rd & 44th Supplements.
Bird Studies Canada. Avibase-The
World Bird Database