LDWF aerial survey: December duck count at 3.02 million birds

Figure is double November’s estimate, but 16 percent below last December

The Louisiana Department of Wildlife and Fisheries’ December Aerial Waterfowl Survey indicates a major migration of birds into the Bayou State has occurred since last month, with 3.02 million birds counted compared to 1.55 million in November.

This December’s count is 16 percent below December of 2016, but still 6 percent higher than the long-term December average of 2.83 million birds — and it’s the fourth consecutive above-average December survey.

The report, compiled by Larry Reynolds, the LDWF’s waterfowl study leader, is printed in its entirety below:

“The estimate of 3.02 million ducks on this survey is twice November’s estimate of 1.55 million, 16% below last December’s estimate of 3.61 million, but 6% higher than the long-term December average of 2.83 million.  It is the 4th consecutive above-average December survey (see Figure 1. below). Estimates for all species except blue-winged teal, gadwall, and mottled duck increased from November with big increases in mallards (6,000 to 94,000), green-winged teal (208,000 to 364,000) and especially pintails (136,000 to 483,000), canvasbacks (3,000 to 207,000) and ring-necked ducks (81,000 to 797,000) accounting for most of the increase in total ducks.  Despite those increases, blue-wings (+8%), shovelers (+15%), and pintails (+40%) are the only dabbling ducks to exceed their long-term December averages while scaup, ring-necks, and canvasbacks exceeded theirs by 40%, 200%, and  320% respectively. By comparison, the estimate of 665,000 gadwalls is 27% below the long-term December average of 906,000.  Clearly a major migration of ducks into south Louisiana occurred since the November survey and was likely aided by freezing temperatures down to south Louisiana last week.”

Distribution of ducks was less skewed toward SW Louisiana with 58% of ducks being counted in that region compared to 63% in November.  That was due to larger increases in diving ducks in SE Louisiana where notable concentrations of ring-necked ducks were seen in the Upper Terrebonne marshes both southeast of Amelia and on Mandalay NWR near Waterproof.  A large concentration of canvasbacks and ring-necks, of which only a small fraction was within the surveyed transect width, was seen west of the Mississippi River across from Delta NWR.  In SW Louisiana, large concentrations of mostly pintails were noted in the marsh between Little Pecan and Grand Lakes and in the agricultural fields north of White Lake, while a large group of ring-necked ducks was seen on a sewage lagoon near Rayne.  November’s large concentration areas of mostly gadwalls south of West Cove and the East Cove Unit of Cameron Prairie NWR were holding fewer birds during this survey.

The 111,000 ducks counted at Catahoula Lake was 3.5 times the total from November due to a big influx of ring-necked ducks and canvasbacks as well as increased number of pintails.  Most birds were counted at the southernmost end of the lake.  Despite being the second highest December count in last 5 year, it remains well below the most recent 10-year average of 151,000.  Water level has remained near the management target of 29.5 feet MSL, but due to growing-season flooding events, moist-soil food production was minimal this year, which likely accounts for lower than average duck use despite favorable water levels.

Water levels across the coastal marsh survey area were lower than in November and were especially low in SE Louisiana.  Mudflat areas and dry marsh were evident in habitats with tidal connections, but lower water levels were noted in almost all habitats.  SAV production was spotty across most of SW LA, and along with poor production of seed-producing annual vegetation in most places due to high water levels in spring and summer, habitat conditions in that region is below average.  Similar to November, some areas of fresh and intermediate marsh, such as south of White Lake continue to be impacted by invasive aquatics, mostly water hyacinth.  Flooding in the agricultural region of SW LA remains at least average with most all managed impoundments flooded and some additional shallow flooding evident in pastures and other agricultural fields despite the lack of recent rainfall.  In SE Louisiana, the low water across the region gave us a great look at SAV production, which confirmed November’s report that it is below average in most locations.  Generally only fair to poor SAV production was noted on most transects except in the brackish marsh south of Delacroix.

Another 15,000 ducks were counted on the Northwest Louisiana survey, primarily on the locks, lakes,

oxbows, and fields along the Red River and upper Toledo Bend reservoir. That is over twice the 7,000 counted in November and 50% higher than the December average of 10,000 for this survey.   Gadwall (4,600) was the most abundant species and along with mallards (2,800), ring-necked ducks (2,100), shovelers (1,800), and pintails (1,100) accounted for 83% of the ducks counted.  Water on the landscape remains below average, and 10,500 of the total ducks were counted on flooded managed habitats near Loggy Bayou and Bayou Pierre, with another 2,300 counted on the Red River between lock 5 and Shreveport.

Conversely, in Northeast Louisiana, only 159,000 ducks and 219,000 geese (92% snow geese) were counted on selected habitats during the traditional cruise survey that was standardized in 2005.  That is fewer than the 247,000 ducks and 249,000 geese counted in November, and far fewer than the 594,000 ducks and 402,000 geese counted last December, which was the highest December count since 2005.  Four December surveys in NE LA have been missed or incomplete since 2005, so comparisons with averages may be suspect, but this survey is 30% below the December average of 227,000 ducks but 20% higher than the December average of 183,000 geese.  Pintail (51,000) was the most abundant duck species that along with gadwall (48,000), shoveler (27,000), green-winged teal (17,000), and mallard (15,000) accounted for nearly all ducks counted. Of those species, all but mallards declined from the November survey; mallards increased nearly 50%. Ducks and geese were concentrated in flooded rice fields in 3 general areas: Bunkie/Grand Cote, east of Hebert in Richland Parish, and Bonita/Mer Rouge. Bunkie/Grand Cote held about 50% of the ducks while about 50% of the geese were counted in Bonita/Mer Rouge.  The surveyed landscape remains very dry, with only managed water available in most locations.  Water levels in natural habitats are low with very little forage evident.  The LDWF Monroe Office reported the region is 14 inches below normal rainfall, which has created difficulties with both natural flooding and pumping of WMA waterfowl impoundments.  Habitat conditions remain relatively poor, and hunters are reminded to be cautious when using WMAs because of low water in many locations.

Lastly, the scaup survey on Lakes Maurepas, Pontchartrain, and Borgne will be flown on Friday.  Those data will be added to this report before it is posted to the LDWF website.