Arkansas Completes First Aerial Duck Surveys
Mallard abundance low..
LITTLE ROCK AR --(AmmoLand.com)- Biologists with the Arkansas Game and Fish Commission recently completed the first aerial waterfowl survey of the 2009-2010 duck season, marking a new era in Arkansas duck counts. AGFC has changed its aerial survey method for the Mississippi Alluvial Valley (the Delta) to more reliably estimate duck numbers in the region.
Instead of the “cruise” surveys of the past, in which biologists fly over traditional waterfowl hot spots to count ducks, AGFC will now use a “transect” method. The cruise method is inherently biased because observers can’t account for unsampled areas during each survey. While no method allows biologists to generate a number for absolute abundance, the transect method allows for more standardized sampling and more reliable counts.
The transect method entails flying a randomly selected portion of transects – west-east lines drawn across the Delta at 500-meter intervals – and counting all ducks seen along those lines and using those counts to calculate an estimate of duck numbers across the entire Delta. AGFC’s effort is part of a partnership with the Mississippi Department of Wildlife, Fisheries and Parks, the U.S. Geological Survey and the Lower Mississippi Valley Joint Venture to generate reliable estimates across a large portion of the Mississippi Alluvial Valley over time.
AGFC completed the November 2009 estimates earlier this week, and they seem to match much of the anecdotal observations over the past several weeks. There aren’t many mallards in the Delta right now, but observers did see good numbers of other dabbling ducks, including pintails, northern shovelers and gadwalls. Duck distribution appeared to be spotty, with large concentrations here and there across the Delta but without good numbers of ducks scattered throughout the region.
Observers were somewhat surprised by the absence of water in many areas in light of the severe flooding that occurred in late October. While many areas, especially along river corridors, remained flooded, it appeared that many farmers had allowed much of the water to drain in an attempt to salvage harvestable crops.
November population estimates for the Arkansas Delta were 124,065 mallards, 522,662 other dabbling ducks and 147,678 diving ducks for a total of 794,405 ducks. Because of the change in survey methods, these numbers should not be compared with past counts. This count should be considered the first point in a developing collection of Delta duck counts.
Population estimates for western Arkansas, which are still being conducted by the cruise method because of limited waterfowl habitat in that portion of the state, were 20,105 total ducks (5,480 mallards) in southwest Arkansas and 31,000 total ducks (11,000 mallards) in northwest Arkansas.
In addition to the recent aerial waterfowl survey data, AGFC encourages hunters to take advantage of several other new tools to track waterfowl numbers and migration.
AGFC has recently developed duck density maps. The maps, one for relative density of all ducks and the other for relative mallard density, use results from aerial surveys and spatial data models to reflect relative densities of ducks in the Delta region. While the maps are helpful, hunters should understand the maps represent relative density for a given survey period and not absolute duck numbers. For example, it’s reasonable to assume that what appears as a high-density mallard area in November will likely correspond to a lower absolute number than in early January because mallard numbers typically peak in early January. The maps are available at http://www.agfc.com/pdfs/waterfowl/Nov09DuckDensity.pdf and http://www.agfc.com/pdfs/waterfowl/Nov09MallardDensity.pdf.
Since AGFC and Mississippi waterfowl managers conduct counts using the same methods and at approximately the same times, hunters may seek additional information on Mississippi’s Web site at http://home.mdwfp.com/ContentManagement/Html/htmldownload.aspx?id=327. Combined with Arkansas’s counts, that information may provide a more complete picture of waterfowl distribution across a larger portion of the Delta.
Other tools that may be helpful for hunters include a new weather severity index developed by Mississippi State University researchers. The index is an attempt to forecast potential waterfowl migration movements based on weather data throughout the Mississippi Flyway. The index is available at http://www.cfr.msstate.edu/kennedychair/weather.asp.
The Missouri Department of Conservation, in cooperation with Arkansas and several other state and federal agencies, has developed a mallard migration map that can be viewed at http://www.mdc.mo.gov/hunt/wtrfowl/migration.php.
Information on river levels can be found at: http://www.srh.noaa.gov/lmrfc/ or http://water.usgs.gov/realtime.html. Sunrise/sunset tables are available at: http://aa.usno.navy.mil/data/docs/RS_OneDay.html and in the Arkansas Waterfowl Regulations Guide.