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Big day interpretation



I just received the 2002 ABA big Day Report and have spent a few hours
mesmerized by the pure numbers and lists of state lists, region lists etc.
I have also been humbled as I compare my own numbers to those around the
world, and it is in this field of comparative scrutiny that I have a
question for those of you who like me enjoy comparing state and individual
list totals.

I began by comparing American and Canadian state totals (not big day
totals but the total number of birds seen in each state/province by
individuals over the course of their birdign careers). In this field N
Carolina has roughly the same number of species as Illinois and Virginia.
No big surprise here, but the discrepancy is in the number of birders
whose individual state lists approach the total number of species accepted
from that state. Here in NC we have an official list of 440 species and
four of us have seen more than 400. TO take a random number, the 25th
"seeded" birder in our state (Cliff Comeau) stnads at 310. BY comparison
Virginia has 430 species and Illinois the same number of total species
seen in the state. Hoever, the highest "seeded" birder in VA has only 364
species and the 25th seeded only 270 (which in NC would put one in the
38th position). The topmost birder in Illinois has 405 species and he is
the only one from Illinois to break the 400 mark. The 25th seeded Illinois
birder has 284 species. It is clear from this that an NC is an unusually
"competitive" state and that you have to work harder here to get on the
list than you would in a state with a similar avifauna.

Now my question is about how to interpret this discrepancy. My first
inclination was to say that this is an indication that we in NC have an
unusually vibrant and active birding community and thus ahigher percentage
of our birders approach the total possible species limit than in Illinois
and VIrginia. I dont want to detract from the accomplishments of our NC
birders, but it does seem to me that this explanation doesnt quite acount
for the discrepancy. Both Illinois and Virginia are well to do, urbanized
states with relatively large populations (larger and more urbanized than
NC in fact), and this should translate into at least as competent a
birding comunity there.

So, how else might one interpret this discrepancy? One explanantion that
does occur to me is that some states (like Massachusetts) have a very
large number of total species (470) because the birding community there is
older and thus over the decades they have built up the total species count
by getting rare vagrants which cannot be counted upon by short time
residents of the state. THis would mena that in Mass one would have to
work much harder to get close to the total species mark and that simply
being a good birder would not help get ones state list total very high.
You would have had to live in the state for a long time in order to get
those vagrants which only show up every decade or so, but which drive the
state total up to a number as high as 470. NC by contrast has a newer
birding community and our 440 species may include a larger percentage of
birds which occur here regularly and thus can be counted upon by even
newcomers to the state.

Or are there any other interpretations besides the first one (which is
very tantalizing but also self-congratulatory) an the second (which
ignores the fact that a state like Virginia would have birding community
of roughly the same age and standing as NC).

Sorry for a very long email, but this question has bugged me for more than
a year and finally I thought that I would pose it to the entire group in
the hopes that those of us interested in the sociology/statistics of
birding may be able to provide some fresh ideas--afterall, half the fun of
birding is comparison (no, not quite half, but...)

Shantanu Phukan
Carrboro, NC

*****************************************************
SHANTANU PHUKAN
Lecturer in Urdu-Hindi & Indian Literature
University of N. Carolina, Chapel Hill
Curriculum in Asian Studies
Alumni Hall 413C
Chapel Hill, N.C. 27599

phukan@email.unc.edu
919-962-6825
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