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 quad’s 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 it’s so windy that you can’t hear or see them … 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 don’t 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 “mercenaries” to boost phrs in quads that haven’t 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 SPECIFY 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 1 Feb 2011),

or for just the web page itself:

Unofficial Quad Stats Web Page

updated 1 Feb 2011

 

For Mike Baldwin’s map of coverage through 31 Jan. 11, click here.

For Mike Baldwin’s detailed map of coverage for N LA through 31 Jan. 11, click here.

For Mike Baldwin’s detailed map of coverage for SW LA through 31 Jan. 11, click here.

For Mike Baldwin’s detailed map of coverage for SE LA through 31 Jan. 11, click here.

For Mike Baldwin’s map of species richness through 23 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 isn’t a responsibility, just a suggestion.]

Maps.

SEE: http://appl003.lsu.edu/natsci/labirdweb.nsf/$Content/Find+a+Quad?OpenDocument

Also, try:

http://atlas.lsu.edu/q24k/

 

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 (2011 in blue):

** = already reached threshold of 20 party/hrs (needs updating)

Abbeville East - Richard Greig
Abbeville West - Richard Greig
Afeman ** – Jay Huner
Alexandria ** - Jay Huner
Allen ** - Terry Davis/Jeff Trahan
Angie - Brian O’Shea
Arizona ** – M. L. Lewis
Arnaudville - Patti Holland
Athens ** – John Dillon
Barataria - David Muth
Barataria Pass - Curt Sorrells
Bastian Bay - Steve Cardiff/Donna Dittmann
Bastrop ** - Stephen Pagans/Joan Brown
Baton Rouge East ** - Jane Patterson
Baton Rouge West ** - Jeff Harris
Baxter Bayou ** - Roselie Overby
Bay Ronquille – Erik Johnson
Bayou Boeuf - Lee Ellis
Bayou Cocodrie – William McGehee
Beggs - Mac Myers
Belle Chase - Lee Ellis
Belle D’Eau ** - Marty Floyd
Belle Passe - Dan Purrington
Belle Rose - Sue Broussard
Benton ** - Jeff & Jean Trahan
Bertrandville - David Muth
Big Bend – Jacob Saucier
Bird Island Point ** - Jonathan Clark
Birds Creek ** – Jim Johnson
Blackburn – John Dillon
Blanchard ** - Larry Raymond
Blankston - Joyce Bennett
Bluff Creek - Michael Seymour
Bogalusa W - Brian O’Shea
Bosco ** - Joyce Bennett
Bossier City - Jim Ingold
Bossier Point ** - Terry Davis
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
Bush – Mary Mehaffey
Cadeville ** - Stephen Pagans/Joan Brown
Calhoun ** - Stephen Pagans
Calumet Island - Steve Cardiff/Donna Dittmann
Cameron ** -
Caminada Pass - Curt Sorrells
Carencro ** - Bill Fontenot
Carville ** – Lindsay Seeley/Van Remsen
Cecilia ** - Bill Vermillion
Centerville NW – Brian O’Shea
Chalmette ** - Glenn Ousset
Chef Menteur - Phillip Wallace
Cheneyville - Marty Floyd
Church Point - Jay Huner
Clay – John Dillon
Clear Lake ** - Nancy Menasco
Clifton - Brian O’Shea
Cocodrie Lake - Jim Johnson
Colfax - Jay Huner
Colquitt ** - John Dillon
Collinston West ** - Roselie Overby
Columbia - Joyce Bennett
Comite ** – Brian O’Shea/Laurence Binford
Covington **  -
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
Downsville South - Stephen Pagans
Duson ** - Paul Conover/Dave Patton
E. Isles Dernieres – E. J. Raynor
Eagle Bend – David Ringer
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
Farmerville - ** -
Fish Lake ** - Stephen Pagans/Joan Brown
Folsom ** - Janine Robin
Forest Hill ** - Steve Shively
Forked Island NW - Paul Conover
Fort Polk ** - Jim Johnson
Franklinton – Janine Robin
French Settlement ** – Sue Broussard/Van Remsen
Frost ** - Jane Patterson
Fullerton Lake ** - Steve Shively
Gardner ** - Steve Shively
Gheens -
Gibsland ** - Rosemary Seidler
Gibson - Steve Cardiff/Donna Dittmann
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 ** – Hans Holbrook/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
Holden – Brian O’Shea
Holly Beach -
Holly ** Ron Martin
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
Jena East ** - Jonathan Clark
Jericho ** - Jay Huner
Johnsons Bayou -
Kaplan North ** - Erik Johnson
Kaplan South ** - Erik Johnson
Keatchie ** - Ron Martin
Kilbourne ** - Roselie Overby
Koran ** - Jim Ingold
LaBranche - Melvin Weber/Ron Stein
Lac Sainte Agnes ** - Jacob Saucier
Lacombe ** - Stefan & Mollie Woltmann
LaCour – Van Remsen
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
Lillie ** - Jeff Trahan/Terry Davis
Little Sandy Creek ** - Rosemary Seidler
Little Woods ** - Glenn Ousset
Lockport - Lee Ellis
Lottie – Danny Dobbs
Luling - Hans Holbrook
Lutcher ** - David Sylvest
Madisonville ** - Chris Brantley
Mandeville ** - Chris Brantley
Mangham ** - Joyce Bennett
Maringouin ** –
Maringouin NW ** – Danny Dobbs
Marksville South – Jacob Saucier
Marsalis ** – John Dillon
Martinville ** – Tom Trenchard
Mason - Joyce Bennett
Mer Rouge ** - Steve Pagans/Joan Brown
Mermentau – Paul Conover
Milton ** - Erik Johnson
Minden North - John Dillon
Minden South – John Dillon
Mire – Danny Dobbs
Monroe North ** - Steve Pagans/Joan Brown
Monroe South ** - Joyce Bennett
Mooringsport - Larry Raymond
Moreauville – Jacob Saucier
Morgan City SE/Steve Cardiff/Donna Dittmann
Mound – David Ringer
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
North Shore – Mary Mehaffey
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 – D. Brown/Patten
Portage ** - Bill Vermillion
Powhatan -
Prairieville – Sue Broussard
Pride – Charles Williams
Rapides ** - Steve Shively
Rayville ** - Joyce Bennett
Reserve ** - Melvin Weber/Ron Stein
Rigolets ** -
Ringgold – Terry Davis
Riverton ** - Joyce Bennett
Robert – Mary Mehaffey
Rocky Branch ** - Stephen Pagans/Joan Brown
Rogillioville –
Roseland - Brian O’Shea
Rosepine - Matt Pontiff
St. Francisville – Matt Brooks/Keith Ouchley
St. Gabriel ** - Van Remsen/Steve Cardiff/Donna Dittmann
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
Sparta ** - Terry Davis
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 ** - David Ringer/Boslers
Thibodaux ** - E. J. Raynor
Thornwell ** - Steve Cardiff/Donna Dittmann
Triumph -
Venice - Dan Purrington
Vicksburg W – David Ringer
Vinton -
Vivian North ** - Richard Gibbons
Vixen - Joyce Bennett
W. Isles Dernieres – E. J. Raynor/Steve Cardiff/Donna Dittmann
Waldheim ** - Mary Mehaffey
Walls ** - Van Remsen
Wallace Lake ** - Mac Hardy/Rosemary Seidler
Wardview ** -
Watson ** - Laurence Binford
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
Whiteville - Bill Vermillion
Wilson –
Womack ** -
Woodworth East - Marty Floyd
Woodworth West ** - Steve Shively
Wright ** - Dave Patton
Youngsville ** - Erik Johnson
Zachary ** – Phil Stouffer/Walker Wilson

 

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