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PURPOSE
The Mid-winter Waterfowl Survey is a nationwide effort to survey waterfowl in areas of major concentration on their wintering grounds and provide winter distribution and habitat affiliations. This survey also serves as a primary source of data on population trends for some species that breed in remote Arctic locations and are difficult to survey using traditional methods. Therefore abundance indices for some of these species are obtained from surveys on wintering areas. For species not covered in other population surveys these indices provide direct inputs into management programs such as harvest management plans.

LIMITATIONS
The Mid-winter Survey has been criticized for its lack of a statistical sampling design, differences in field methods among states, changes in survey personnel and variability in personnel experience, variation in survey effort, and changes in surveyed areas within states. Eggeman and Johnson (1989) summarized many of the limitations with the Atlantic Flyway Mid-winter Waterfowl Survey. Because of these limitations, caution must be used in making inferences about population trends using data from this survey. Any such attempts should be made in close consultation with state and Federal agency personnel that have knowledge of specific limitations of these data for individual states and species.

LITERATURE CITED
Eggeman, D. R. and F. A. Johnson. 1989. Variation in effort and methodology for the midwinter waterfowl inventory in the Atlantic Flyway. Wildlife Society Bulletin 17:227-233.

Sharp, D.E., K.L. Kruse, and P.P. Thorpe. 2002. The Midwinter Waterfowl Survey in the Central Flyway. Division of Migratory Bird Management, USFWS, Denver, CO.

PROCEDURES
Survey design and field procedures are determined by individual states. The Mid-winter Survey is, today, conducted primarily by fixed-wing aircraft, although some states use helicopters and/or conduct counts from automobile or boat in certain areas. The Mid-winter Survey is known as a “cruise” survey, in that specific predefined transects are not defined. Instead, an aerial crew determines the best and most practical means to conduct a complete count of all waterfowl within a predefined unit area. The exact means of coverage may vary from year to year; however, the objective is to obtain a complete count of all waterfowl within the survey unit. The survey is conducted annually and typically starts the first week of January. Cooperators then enter data into a data entry application and the data is sent directly to the respective Flyway office where an annual report is produced and data are stored.

SURVEY COVERAGE MAPS
All Flyways combined
Atlantic Flyway
Mississippi Flyway
Central Flyway
Pacific Flyway

Atlantic Flyway

POINT OF CONTACT
Tony Roberts
Atlantic Flyway Representative Assistant, US Fish and Wildlife Service
phone: (802) 342-4926
anthony_roberts@fws.gov

DATABASE NOTES
This database contains summarized count data for survey zones for each state. Data at the state level are available since 1955. In many years, a few survey units within a flyway may not be surveyed because of problems with weather, aircraft, crews, etc. However, these problems do not affect the use of the data at the flyway scale. Occasionally, there are major disruptions to the survey of which users of the data should be aware. Inconsistencies that occurred during the period covered by this database are listed below.

• 2001 - Estimates for portions of Florida were based on previous 3-year average.
• 2003 - Florida data are incomplete. Data from the USFWS Redhead Survey areas are unavailable.
• 2004 - No survey conducted in Florida. Estimates for Florida based on 2000-2002 average.
• 2005 to present - No survey conducted in Florida. Totals for mottled ducks, whistling ducks, blue-winged teal, redheads, scaup, ring-necked ducks, and to a lesser extent, wigeon and shovelers are especially suspect.
• 2007
  • No survey conducted in Vermont.
  • Connecticut conducted a ground-based survey of black duck and brant concentration areas only.
  • New York survey data are from Long Island only. Counts for black ducks and brant are probably reasonable, but counts for other species are likely too small, especially mallards, canvasbacks, Canada geese, and mute swans.
• 2008 - No survey conducted in South Carolina
• 2009 - No survey conducted in Florida. New York survey data are from Long Island only
• 2010 - No survey conducted in Florida. New York survey data are from Long Island and Lake Champlain only
• 2011
  • New York survey data are from Long Island and Lake Champlain only.
  • Failure of the voice/GPS computer program prevented Pennsylvania from completing or compiling aerial survey segment and sub-segment data. In an effort to reconcile lost data, ground counts were performed, although in some cases even these efforts were not feasible. Therefore, counts for this state are not comparable to previous years. Extent of data loss for individual species varied from minimal (snow geese, tundra swans) to moderate (Canada geese and most duck species) to extensive (mergansers).
• 2012 and 2013
  • New York survey data from Long Island only. Counts for black ducks and brant are probably reasonable, but are likely too small for other species, especially mallards, canvasbacks, Canada geese, and mute swans.
  • Flyway totals are not comparable with totals from previous years because of lack of survey in Florida. Totals for mottled ducks, whistling ducks, blue-winged teal, redheads, scaup, ringnecked ducks, and to a lesser extent, wigeon and shovelers are especially suspect.
• 2014
  • New York survey data from Long Island, Lake Champlain, and western part of state only. Counts for black ducks and brant are probably reasonable, but are likely too small for other species, especially mallards, canvasbacks, Canada geese, and mute swans.
  • Flyway totals are not comparable with totals from previous years because of lack of survey in Florida. Totals for mottled ducks, whistilng ducks, blue-winged teal, redheads, scaup, ringnecked ducks, and to a lesser extent, wigeon and shovelers are especially suspect.
  • No survey conducted in Vermont.
• 2015
  • New York survey data from Long Island, Finger Lakes region, Great Lakes shorelines, and Lake Champlain. Counts are not comparable to previous years due to wide variation in survey area.
  • New York survey data from Long Island, Finger Lakes region, Great Lakes shorelines, and Lake Champlain. Counts are not comparable to previous years due to wide variation in survey area.
• 2016
  • New York survey data from Long Island, Finger Lakes region, Great Lakes shorelines, and Lake Champlain. Counts are not comparable to previous years due to wide variation in survey area.
  • Only Delaware, Georgia, Maryland, and Rhode Island counted all birds seen in the entire survey area. New Jersey, New York, North Carolina, and Pennsylvania results are not comparable to previous years except for Atlantic brant and tundra swans. Connecticut, Massachusetts, South Carolina, and Virginia reported only Atlantic brant and tundra swans. All other states did not conduct a survey.

Mississippi Flyway

POINT OF CONTACT
David Fronczak
5600 American Blvd., West, Suite 950
Bloomington, MN 55437-1458
phone: (612) 713-5411
fax: (612) 713-5424
dave_fronczak@fws.gov

DATABASE NOTES
This database contains summarized count data for survey zones for each state. Data at the state level are available since 1955 and at finer levels since 2011 for the Mississippi Flyway. In many years, a few survey units within a flyway may not be surveyed because of problems with weather, aircraft, crews, etc. However, these problems do not affect the use of the data at the flyway scale. Occasionally, there are major disruptions to the survey of which users of the data should be aware. Inconsistencies that occurred during the period covered by this database are listed below.

• 1966 - Unidentified ducks includes 39,758 wood ducks
• 1967 - Unidentified ducks includes 28,452 wood ducks
• 1968 - Unidentified ducks includes 28,410 wood ducks
• 1969 - Unidentified ducks includes 22,526 wood ducks
• 1969-97 - Surveys conducted in December, January thereafter
• 1970-79
  • Goose Estimates are from the December Goose Survey
• Unidentified ducks includes wood ducks except within Ontario
• Eider and Scoter numbers combined
• 1980-89 - Goose Estimates are from the December Goose Survey
• 1980-81
  • Unidentified ducks includes wood ducks except within Ontario
• Eider and Scoter numbers combined
• 1990-98 - Goose Estimates are from the December Goose Survey
• 1994 - No surveys were conducted in Michigan
• 1996 - No December goose survey in Wisconsin & Ontario
• 1997 - No December goose survey in Wisconsin
• 1998 - No December goose survey in Ohio
• 2004 - No surveys were conducted in Wisconsin
• 2006 - Within Mississippi the transect survey officially replaced the traditional survey in Zone 1. Only mallards and unidentified ducks were counted.
• 2010 - Within Arkansas the transect survey officially replaced the traditional survey for Zone 2 & 3.
• 2012-13 - No survey conducted in Michigan.

DOWNLOADABLE FIELD DEFINITIONS

Central Flyway

Dave Olson
acting Central Flyway Representative
U.S. Fish and Wildlife Service
PO Box 25486-DFC
Denver, CO 80225
phone: (303) 236-6284
dave_olson@fws.gov

DATABASE NOTES
This database contains summarized count data for survey zones for each state. Data at the state level are available since 1955 in the Central Flyway. In many years, a few survey units within a flyway may not be surveyed because of problems with weather, aircraft, crews, etc. However, these problems do not affect the use of the data at the flyway scale. Occasionally, there are major disruptions to the survey of which users of the data should be aware. Inconsistencies that occurred during the period covered by this database are listed below.

• 2002 - Within Colorado, 37,809 unidentified ducks were unknown dabblers.
• 2004 - The USFWS did not participate in the 2004 Mid Winter Survey so coverage was not complete in the High Plains of Texas.
• 2005 - Texas did not survey the Coastal Sand Plains due to weather and equipment problems.
• 2007 - Texas did not survey the Rolling Plains and Sand Plains due to weather and equipment problems.

DOWNLOADABLE FIELD DEFINITIONS

Pacific Flyway

Steve Olson
Wildlife Biologist
Pacific Flyway
Division of Migratory Bird Management
U.S. Fish and Wildlife Service
1211 SE Cardinal Court, Suite 100
Vancouver, WA 98683
phone: (360) 604-2559
fax: (360) 604-2505
steve_olson@fws.gov

DATABASE NOTES
This database contains summarized count data for survey zones for each state. Data are available since 1955 for the Pacific Flyway. As stated above under “Limitations”, in many years survey units within a state may not be surveyed because of problems with weather, aircraft, crews, etc. Therefore, we strongly caution against use of these data for any purpose other than general trends.

Colorado Note: Data collection and summation methods differ in Colorado compared to other states within the flyway. Therefore, until we develop a way to present the data through this website, it will remain unavailable within in our query option and report pages. We hope to complete this by the end of the year. In the meantime, please contact Steve Olson from the Pacific Flyway to obtain Colorado data.

Arizona Zone Data: When downloading Arizona data from the query results screen, note that when you select, 'open' rather than 'save,' the data within the Zone field, shows up as a date (i.e. 1-Jun, 2-Jun, 3-Jun) rather than the true zone, (06-1, 06-2, or 06-3). This is Excel's default and we are not sure how to adjust it. To accommodate, click the save button rather than the open button when downloading the ASCII file. This will correct the problem.

Alaska: The Pacific Flyway has requested Alaska be added to MWS database because their Black Brant, Emperor Goose, and Steller's Eider counts directly affect some Pacific Flyway management plans and actions. Only the areas of Izembek NWR and Sanak Island are counted in these Alaskan MWS Flights.

All: An Emperor Geese row has been added as a column of species because Alaska counts them, along with Black Brant and Steller's Eider on their flights. Steller's Eiders will be included in the "Eiders" row. Alaska does not count other species of waterfowl during these surveys.

California Note: In 2015, California completely changed their survey method from a general cruise survey to a transect-based survey. California's numbers are considered estimates and are not comparable to previous years because of the difference in survey methodology. These new numbers are estimates, so error, precision, and more information can be obtained by contacting the state. Also, under new survey methodology (2015), geese and swans other than brant were not reported; these species are monitored separately with surveys conducted earlier in the season.

DOWNLOADABLE FIELD DEFINITIONS

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