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RFI - Annually Occurring Birds in States and Provinces (fwd)



Hi C-birders,

The following request was posted on BIRDCHAT by Blake Maybank, the person 
in charge of the ABA's annual report of everyone's lists and big days. In 
short, he wants a list of the species which have occurred in each of the 
last 10 years for each state. Hopefully someone on this list has access 
to that information for North and South Carolina. Please reply to Blake 
if you can help him out.

Speaking of Big Days, I did one with Will Cook and Rob Van Epps on 
November 20. Rob has our official list, so I won't go into much detail; 
we really did not see much of note, and if we had, it could have left in 
the intervening 9 days. We totalled 113 birds in about 13 hours. For my 
part, the least expected bird was probably the Orange-crowned Warbler, 
which Will pished in at Alligator River NWR. We also had a decidedly 
out-of-season Common Tern at Pea Island, in the north pond. We could not 
find the Common Redpoll which had been reported there, nor did we find 
any of the Eurasian Wigeon or American Tree Sparrows at Pea Island, nor 
the Ash-throated Flycatcher at Bodie Island. Also, many typical winter 
birds were either very rare or absent: for instance, we whiffed on Great 
Cormorant, and saw only one each of Red-throated Loon and Horned Grebe. 
We also missed most of the irruptive species, going without Pine Siskin 
and Snow Bunting on the day, although we did find several Red-breasted 
Nuthatches on Bodie Island.

As for Thanksgiving, I spent mine up in New England with my folks. We 
spent the actual holiday night in a B&B in Kennebunkport, Maine, to 
relieve Mom of the cooking duties. I spent part of Friday morning out on 
the front porch scanning the ocean, and spotted Common Loon, Bufflehead, 
Common Goldeneye, Surf Scoter, Oldsquaw, and Common Eider out there. I 
also spent Sunday morning and afternoon with the Brookline Bird Club 
field trip to Newburyport and vicinity, adding Lapland Longspur and Red 
Crossbill to my Massachusetts state list and seeing a few other 
interesting birds. High point was probably the Merlin which nailed a 
Horned Lark and ate its lunch while we watched.

So here, finally, is Blake's message. Good birding!

Josh

----------------------------------------------------------

Date:         Sat, 27 Nov 1999 08:15:33 -0400
From:         Blake Maybank <maybank@NS.SYMPATICO.CA>
Subject:      RFI - Annually Occurring Birds in States and Provinces

Hello Birdchatters;

I edit the Big Day/List Report for the American Birding Association, and am
currently experimenting with changing the Listing Reporting Thresholds for
states and provinces.  In order to continue with the experiment, I require
a missing ingredient, specifically, the number of species that are of
annual occurrence in each state and province.   I call this the "Core List".

The BirdChat readership covers the continent of North America (and beyond),
and I expect there are chatters from almost each state and province.  I'd
appreciate it if you could consult your own state or province list, and
make note of which species are of annual occurrence (having been seen in
each of the previous ten years), and add them up.  In other words, simply
provide me with the total of the number of each species that occurs
annually in your state or province.  It doesn't matter if there are only
one or two records annually for a particular species.  If it has appeared
in each of the past 10 years, it can be considered annual for the purposes
of this calculation.  And don't get too fastidious; a species here or there
isn't going to make too much of a difference

The remainder of the birds on the list will presumably be vagrant (ie, of
less-than-annual occurrence).

I already have a few states and provinces in hand.  They are:

Alabama
Illinois
Indiana
New Hampshire
Washington

Manitoba
New Brunswick
Newfoundland
Nova Scotia

I'll post the completed list on BirdChat later on, as some of you might be
curious regarding the % of vagrants in each region.

I'd greatly appreciate your assistance.  All contributions will be
acknowledged in the annual List Report for the A.B.A..

Cheers,

Blake Maybank
maybank@ns.sympatico.ca

If you are curious regarding the philosophical underpinning of this
experiment, you may read further.

LISTING THRESHOLD DISCUSSION

The current approach to calculating the Listing Threshold is certainly
simple (50% of each state or provincial species list), but is rather crude.
 There are a couple of problems with this approach.  One is that it is
necessary to keep revising the thresholds as state and provincial lists
grow (which is work the Listing Editor doesn't need), and the second is
that provinces and states lists are not "created equal" -- some have a much
higher proportion of rarities and vagrants.  This means, for example, that
in Nova Scotia, which has a high proportion of rarities in its provincial
list of 440, it can take a year of birding to reach the reporting
threshold.  By contrast, in Manitoba, where a much higher proportion of its
380 species are of routine occurrence, you can reach the threshold in one 
day.

The thresholds are largely irrelevant to in-province or in-state birders,
as they can reach the threshold within a year or two at worst, and usually
much more quickly.  The thresholds are more of a concern to visiting
birders.   It is my view that a visiting birder should have to make two or
three trips, of a week or more in order in length, to have a reasonable
chance of seeing enough species to pass the threshold of a state or
province.  One trip should never be enough, but by the same token it
shouldn't be necessary to take up temporary residence to achieve the needed
totals.

Let's see how the new approach would work.

I am starting with the assumption that for an "average" list 30% of the
birds are vagrant.  If a region has a higher % of vagrants the current
threshold should be lowered, and those with a lower % will have their
thresholds raised.

For example, the Provincial List for Nova Scotia is 440, which under the
current system gives a Reporting Threshold of 220.  The number of species
that occur each year in Nova Scotia is about 280, meaning the 37% of the
provincial list is composed of vagrants.  The Manitoba Checklist is 380,
with a current threshold of 190 (there are 10 Big Day totals for the
province greater than 190, and anyone with a few days in spring is surely
going to reach this total).  The number of species that occur each year in
Manitoba is about 295, meaning the 23% of the provincial list is composed
of vagrants.  Under my new system the threshold for Nova Scotia will be
lowered, and that for Manitoba will be raised.

Once I have the new "Core" lists, I will begin to play with formulae that
will "level the playing field".  This still isn't a "perfect" system, but
is more fair than the current one, and also has the advantage that it won't
have to be recalculated nearly as often, as the "Core" list of
annually-occurring species won't change that quickly for any state or
province.

Blake Maybank
Editor, American Birding Association (A.B.A.) "Big Day/Listing Report"
Chair, A.B.A. Recording Standards & Ethics Committee
maybank@ns.sympatico.ca

----------------------------------------------------------

Joshua S. Rose
Duke University
Department of Zoology

jsr6@acpub.duke.edu
http://www.duke.edu/~jsr6/