Methodology
for Louisiana Winter Bird Atlas
Van
Remsen, Steve Cardiff, Donna Dittmann, & Richard Gibbons
Louisiana Bird Resource
Center
Synopsis
The LWBA program hopes to generate maps of relative
abundance of birds in the state during late winter. To do this, we borrow the
familiar, standard CBC methodology in terms of party-hours and party-miles to
generate indices of relative abundance, and apply these to 7.5 quad grid cells,
which are roughly 35% as large as a CBC circle. We think that a minimum of 20
party-hours (total; not necessarily all in same day) is necessary to
characterize a quad. These can be distributed in any way within the 6-week
survey period (over the 4-year life-span of the project). In fact, the same
areas can be resampled multiple times as long as the numbers of birds are
calibrated by party-hours and party-miles.
The general idea, at least for the quad compilers,
is to treat the quad survey as a small, square CBC circle and sample
accordingly to produce the standard, familiar "birds/party-hour" data
on relative abundance.
Data-entry and display will all be online, in
partnership with the eBird
program at Cornell Laboratory of Ornithology.
Directions for checking the current list for any
quad ... go through the following
steps:
eBird > Louisiana Winter Bird Atlas (under
"Regional Projects Near You", lower right of screen) > View and Explore
Data > Bar Charts > Atlas Quadrangles in this State ... Continue >
pick quad name from the roster that appears ... Continue. This will generate a
seasonal checklist that will also include Summer Bird Atlas data as well. If
you want to exclude summer-only species, then do "Change Date" and
restrict to "Winter."
Goals
1. Publish an atlas of winter bird distribution for
Louisiana using the same 7.5 quad scale as in the Wiedenfeld & Swan's
Breeding Bird Atlas.
2. Add a level of information not present in Wiedenfeld & Swan or any other
atlas to our knowledge, namely information on relative abundance based on
birds/party hour (or party mile for roadside species). The atlas will reflect
these data with perhaps 5-6 color shades, on a scale such as <1/party-hr,
1/party-hr, 10/ph, 100/ph, and 1000/ph.
3. Have all data displayed online as soon as entered by observers and
subsequently filtered by quad compiler. Allow instantaneous uploading of new
data to web page that displays atlas results.
Methods
1. Overview
This survey method combines the grid approach of an
atlas with the effort-calibrated approach of the CBC. Breeding Bird Atlases
typical provide only presence/absence data and do not provide information on
relative abundance. Therefore, they cannot be used to assess differences in
relative abundance within a state nor long-term population trends. CBC
methodology, in contrast, permits this by calibration of all field data by
party-hours, a technique familiar to all birders. The problem with using CBC
circles for atlasing is that they are too few and too irregularly distributed
geographically. Furthermore, the CBC period is too early in winter, and may not
adequately reflect "true" winter populations. The CBC time period is
not only short but also conflicts severely with major holidays. Also, CBC
circles are so large (ca. 175 sq. miles) that covering them thoroughly requires
substantially more effort relative to the roughly 62 sq. miles of a 7.5 quad.
Finally, in contrast to atlasing efforts, dates for individual CBCs are set in
advance and are essentially irrevocable once set regardless of bad weather;
they are also restricted to a single 24-hr period. The method proposed here
blends the strengths of both atlas and CBC methods and minimizes their
weaknesses.
2. Specifics
a. Each quad has a compiler responsible for doing
surveys and submitting data. Each compiler is encouraged to recruit qualified
help to survey their quad. Data gathered within the quad by observers other
than the compiler are submitted directly to eBird but are eventually filtered
by the compiler before adding to the official database.
b. A survey consists of a bird count, CBC-style
with respect to keeping track of numbers of individual birds, party-hours,
party-miles, and rough habitat coverage. For mapping in the atlas, a quad needs at least 20
party-hours of surveying, hopefully more, over the 4-year lifespan of the
project. Those hours can be
distributed over any number of days within the official "winter
atlas" period. Thus,
flexibility in survey dates allows avoidance of bad weather, and also permits a
single observer to cover different sections of a quad on different days. An ideal survey might consist of the
compiler organizing 2-4 teams to survey sections of the quad on a single day, CBC
style. As long as party-hour and
party-mile data are recorded, the fundamental unit of the atlas, namely
birds/unit effort, remains intact. Repeat surveys of the same spots on different days are also
possible, again as long as the data are calibrated by effort. However, do not bias a quadÕs data by
too many counts from a single spot, e.g., your yard – limit those to say
4-5 representative counts/year. Other than excessive single-point sampling, surveys can be
conducted as often as resources permit.
Do not do surveys during bad weather to minimize "weather
effects" on detection rates. Just use birding common sense, e.g., do not
do surveys of woodland landbirds when itÕs so windy that you canÕt hear or see
them É in other words, keep in mind that the goal is to make the critical unit
for comparing relative abundance, namely birds/party-hr, as representative as
possible and void biasing this downward by surveying in bad weather. Also, use birding common sense again to
get out as early in the day as possible, when detection rates peak.
Quads that donÕt reach the 20-phr threshold might
not be mapped individually, but the data will be used, even if only a single
1-hour sample, for broader regional comparisons and inter-annual
comparisons. No data are discarded. We are seeking funds to hire
ÒmercenariesÓ to boost phrs in quads that havenÕt made it to the 20 phr
threshold. We also may be able to
map quads that have reached only 10 party-hours in analyses of common, widely
distributed species.
c. The minimum unit for data-entry in terms of time
period would be 1 hour. This minimizes the biases of brief sample periods. Once
that threshold is reached, all additional time counts toward the total, even if
not continuous with the first hour. As with CBC methods, avoid counting same
birds more than once in same day.
See FAQ for
additional details (and let Remsen know what else should be addressed at the
FAQ)
3. Date Entry --
The Louisiana Winter Bird Atlas has its own
data-entry page at eBird:
Data-entry Louisiana Winter Bird Atlas: LWBA .
You have to register first if not already an eBird
registrant.
Step 1: under Louisiana
Atlas Program, hit "Submit Observations"
Step 2: either (a) Select from "My Locations" to get to a quad for
which you've previously entered a list, or (b) "Find it on a Map".
Step 3: click on the red balloon closest to your quad.
Step 4: click on your quad's name.
or
at Step 2, go to "Find it by Quad, City ...
" and check the box at the bottom for list of quads. This may be easier
than 2b above, but eBird would prefer you use 2b.
BE SURE TO SPECIFIC AN INDIVIDUAL QUAD
FOR YOUR DATA ... OTHERWISE THEY DO NOT GO INTO THE LWBA DATA-BASE.
Then, enter your bird data by following the
instructions. Put your locality
details in the Comments box for reference. If you have problems, let me or Richard know; this is a novel
program for eBird, so we're still working out the problems. If you don't have computer access, just
send your survey data to us, and we will enter it for you.
Official "Winter" period
Start: 10
January. This avoids the
traditional CBC period and also coincides with the empirical observation that
many "half hardy" species seem to disappear after early January. To some degree, the latter is an
artifact of CBC period coverage, but not entirely.
End: 20
February. With Purple Martins
arriving in mid January, some waterfowl beginning to leave in late January, and
some residents nesting in January, there is no such thing as a
"stable" winter period for the entire avifauna. Late February leaf-out for many trees in
southern Louisiana certainly sets a late limit. An "end" date of 20 Feb. extends the period as long
as possible without major departure of most winter residents. This may not apply to waterfowl, but
waterfowl are not among the species for which this sort of survey is best
suited.
Output
The atlas will consist of maps of the state for
each species with each quad coded for relative abundance of that species in
perhaps 4-6 shades of the same color. The relative abundance scale can vary among species, as can
the unit of analysis (e.g., birds/party-hr on foot, birds/party-hr by car,
etc.). [Details not important until we have a better feeling for the data.]
For fun, we will maintain tallies of total number
of species, total number of party-hours, and so on, divided by region (Coastal
Zone, Southern Interior, Northern Interior; see LA subdivisions
for boundaries). See:
Unofficial Quad
Stats EXCEL file for a downloadable EXCEL
file (updated 3 Feb 2010),
or for just the web page itself:
Unofficial
Quad Stats Web Page
updated 3 Feb 2010
For Mike BaldwinÕs map of coverage
through 2 Feb. 10, click here.
For Mike BaldwinÕs map of species
richness through 2 Feb. 10, click here.
The WBA program
is indebted to Rosemary Seidler for her previous coverage maps – these
made a huge difference in planning this project.
Timeline:
2006-07 - field-test methods on selected quads; promote the program;
plan for 2008
2008 -
all-out quad surveys
2009 - all-out quad surveys
2010 - all-out quad surveys
2011 - all-out quad surveys
2012 - produce print version?
Quad compiler responsibilities:
o All submitted data will be filtered eventually
through the Quad Compiler (details for data submission and uploading to be
worked out with eBird and CLO).
o The Quad Compiler will try to make sure that at
least 20 party-hours are invested in the quad between 10 Jan. and 20 Feb. over
the lifespan of the project (not just a single year) and will make sure the
data are entered into the eBird portal.
Theoretically, you could accumulate the 20 hours on 20 separate 1-hr
time blocks.
o Quad Compilers should consider organizing one or
more all-out 1-day surveys within a quad, carving it up into territories. In
other words, make it like a Christmas Count (but one with the flexibility to
avoid bad weather and holidays).
[No one has done this yet, so this isnÕt a responsibility, just a
suggestion.]
Maps.
SEE: http://appl003.lsu.edu/natsci/labirdweb.nsf/$Content/Find+a+Quad?OpenDocument
Also, try:
Once you've located a quad at the latter, you can
download a good map as a tiff file and then print that out (or save as pdf file
and print that out -- resolution not as good but file size not huge, unlike
tiff files).
Or for GOOGLE quad maps, courtesy Bill Sussky:
minilogic.com/LAQuads/index.html
Quad Compilers
- so far (2010 in blue):
** = already reached threshold of 20
party/hrs
Abbeville East - Richard Greig
Abbeville West - Richard Greig
Afeman – Jay Huner
Alexandria - Jay Huner
Angie - Brian OÕShea
Arnaudville - Patti Holland
Athens – John Dillon
Barataria - David Muth
Barataria Pass - Curt Sorrells
Bastrop **
- Stephen Pagans/Joan Brown
Baton Rouge East ** - Jane Patterson
Baton Rouge West ** - Jeff Harris
Baxter Bayou - Roselie Overby
Bayou Boeuf - Lee Ellis
Bayou Cocodrie – William McGehee
Beggs - Mac Myers
Belle Chase - Lee Ellis
Belle Passe - Dan Purrington
Belle Rose - Sue Broussard
Benton ** - Jeff
& Jean Trahan
Bertrandville - David Muth
Big Bend – Jacob Saucier
BirdÕs Creek - Steve Shively
Blackburn – John Dillon
Blanchard ** -
Larry Raymond
Blankston - Joyce Bennett
Bluff Creek - Michael Seymour
Bogalusa W - Brian OÕShea
Bossier City - Jim Ingold
Boudreaux Lake (Cameron) -
Boyce - Jay Huner
Branch – Paul Conover
Breaux Bridge - Bill Fontenot
Broussard - Danny Dobbs
Bryceland ** -
Rosemary Seidler
Bunkie - Marty Floyd
Buras ** - David Muth
Cadeville ** - Stephen
Pagans/Joan Brown
Calhoun ** - Stephen Pagans
Cameron **
-
Caminada Pass - Curt Sorrells
Carencro ** - Bill Fontenot
Carville – Lindsay Seeley/Van Remsen
Cecilia - Bill Vermillion
Centerville NW – Brian OÕShea
Chalmette ** - Glenn Ousset
Chef Menteur - Phillip Wallace
Cheneyville - Marty Floyd
Church Point - Jay Huner
Clay – John Dillon
Clear Lake - Nancy Menasco
Clifton - Brian OÕShea
Cocodrie Lake - Jim Johnson
Colfax - Jay Huner
Colquitt ** - John Dillon
Columbia - Joyce Bennett
Comite ** –
Brian OÕShea
Cow Island -
Creole -
Crew Lake **
- Joyce Bennett
Crowley East – Paul Conover
Crowley West ** – Heather Baldwin
Curr Creek – Rosemary Seidler
Deer Park – William McGehee
Delacroix **
- Glenn Ousset
Delcambre - Elias Landry
De Loutre **
- Stephen Pagans/Joan Brown
Denham Springs – Jane Patterson
DeRidder - Matt Pontiff
Destrehan – E. J. Raynor
Dixie - Paul Dickson
Downsville North ** - Stephen Pagans/Joan Brown
Duson ** - Paul Conover/Dave Patton
E. Isles Dernieres – E. J. Raynor
East Point - Paul
Dickson
Elm
Grove ** - Nancy Menasco
Elm Park ** - Dorothy Prowell
Elmer ** - Steve Shively
Empire ** -
Enon – Curt Sorrells
Enterprise - Joyce Bennett
Evelyn ** - Hubert Hervey
Fearman Lake - Melanie Driscoll
Fish Lake ** - Stephen Pagans/Joan Brown
Folsom ** - Janine Robin
Forest Hill - Steve Shively
Forked Island NW - Paul Conover
French Settlement ** –
Sue Broussard/Van Remsen
Frost ** - Jane Patterson
Fullerton Lake - Steve Shively
Gardner ** -
Steve Shively
Gheens -
Gibsland **
- Rosemary Seidler
Gilliam **
- Linda Adrion/Rosemary
Seidler
Gilleyville **
- Joyce Bennett
Gonzales **
- Jacob
Saucier
Grand Bayou -
Grand Cane - Rosemary Seidler
Grand Chenier - Dave Patton
Grand Isle - Curt Sorrells
Gueydan - Paul Conover/Dave
Patton
Haaswood ** - Jennifer
Coulson
Hackberry Beach -
Hahnville - Lee Ellis
Haile ** - Stephen Pagans/Joan Brown
Hammock Lake - Erik Johnson
Harrell Lakes - Stephen Pagans/Joan Brown
Hayes – (for boundary between this and Hayes, click here)
Hebert - Joyce Bennett
Hebert Lake - Richard Greig
Hellhole Bayou - Melanie Driscoll
Holden – Brian OÕShea
Holly Beach -
Holly **
Holum - Joyce Bennett
Homer ** - John Dillon
Hortman **
- Rosemary Seidler
Hurricane Branch - Jim Johnson
Indian Beach ** - Dan Purrington
Intracoastal City - Richard
Greig
Ivan - Jeff & Jean Trahan
Jackson - Dorothy Prowell
Jericho ** - Jay Huner
Johnsons Bayou -
Kaplan North ** -
Kaplan South ** -
Keatchie ** -
Keithville – Bill Wood
Kilbourne - Roselie Overby
Koran - Jim Ingold
LaBranche - Melvin Weber/Ron
Stein
Lac Sainte Agnes ** - Jacob Saucier
Lacombe ** - Stefan & Mollie Woltmann
LaCour -
Lake Arthur – Paul Conover
Lake Cataouatche East - David Muth
Lake Charles SE -
Lake Misere – (for boundary between this and Hayes, click here)
Lake Quitman – David Muth
Lake Providence – Roselie Overby
Lafayette ** - Dave Patton
Langston - John Dillon
La Place ** - Melvin Weber/Ron Stein
Latanier Bayou - Paul Conover
Leeville - Dan Purrington
LeRoy ** - Erik Johnson
Little Sandy Creek ** -
Rosemary Seidler
Little Woods **
- Glenn Ousset
Lockport - Lee Ellis
Lottie – Danny Dobbs
Luling -
Lutcher - David Sylvest
Madisonville ** - Chris Brantley
Mandeville - Chris Brantley
Mangham ** - Joyce Bennett
Maringouin NW – Danny Dobbs
Marksville South – Jacob Saucier
Marsalis – John Dillon
Martinville – Tom Trenchard
Mason - Joyce Bennett
Mermentau – Paul Conover
Milton ** - Erik Johnson
Minden North - John Dillon
Minden South – John Dillon
Mire – Danny Dobbs
Monroe South ** - Joyce Bennett
Mooringsport - Larry Raymond
Moreauville – Jacob Saucier
Mt. Airy NW - Richard Gibbons
New Orleans East ** - Phillip Wallace
New Orleans West – John Sevenair
New Roads ** -
Mara Domingue
Nicholson ** - Jennifer
Coulson
North Highlands **
- Larry Raymond
Oak Grove -- Roselie Overby
Pass Tante Phine - Dan Purrington
Patterson - Jay Huner
Peveto Beach -
Phoenix **
- Glenn Ousset
Pioneer ** - Roselie Overby
Pilottown - Dan Purrington
Plaquemine ** - Van Remsen
Plaucheville **
- Jacob
Saucier
Point ** - Stephen Pagans/Joan Brown
Point a la Hache ** - Phillip
Wallace
Pontchatoula - Chris Brantley
Portage ** - Bill Vermillion
Powhatan -
Prairieville – Sue Broussard
Rapides **
- Steve
Shively
Rayville **
- Joyce Bennett
Reserve ** - Melvin Weber/Ron Stein
Rigolets -
Ringgold – Terry Davis
Riverton - Joyce Bennett
Rocky Branch ** - Stephen Pagans/Joan Brown
Rogillioville –
Roseland - Brian OÕShea
Rosepine - Matt Pontiff
St. Francisville –
Matt Brooks/Keith Ouchley
St. Gabriel ** - Richard Gibbons
St. Landry -
St. Tammany – Harvey Patten
Savoie - Lee Ellis
Shreveport East ** - Jean and Jeff Trahan
Shreveport West - Charlie Lyon
Simsboro ** - Rosemary Seidler
Smith Bayou -
Sorrento **
- Jay Huner
South Point - David Muth
Spanish Fort SE ** - Phillip Wallace
Spokane – William McGehee
Spring Ridge **
- Larry Raymond
Sterlington ** - Stephen Pagans/Joan Brown
Stonewall **
- Hubert Hervey
Sugartown NE - Steve Shively
Sulphur -
Summerfield - John Dillon
Tallulah –
Tensas Bluff -
Thibodaux **
- E. J. Raynor
Thornwell ** -
Triumph -
Venice - Dan Purrington
Vinton -
Vivian North ** - Richard Gibbons
Vixen - Joyce Bennett
W. Isles Dernieres – E. J. Raynor
Wallace Lake - Mac Hardy/Rosemary Seidler
Watson ** -
Weeks - Erik Johnson
Welsh North ** – Carol Foil
West of Johnsons Bayou -
West Monroe North ** - Stephen Pagans/Joan Brown
West Monroe South ** - Stephen Pagans/Joan Brown
Weyanoke ** – Phil Stouffer
White Castle - Van Remsen
Wilson –
Woodworth East
- Marty Floyd
Woodworth West ** - Steve Shively
Wright **
- Dave Patton
Youngsville ** -
Erik Johnson
Zachary – Phil Stouffer
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