For the second year in a row, unseasonably warm temperatures apparently prompted large numbers of ducks to bolt from the state — or at least move into areas not included in the annual January aerial waterfowl survey, according to the Louisiana Department of Wildlife and Fisheries.

Larry Reynolds, the state’s waterfowl study leader, estimated 2.05 million birds in the state when the survey was flown during the first two weeks of 2017, down 43% from the 3.61 million birds counted in December — the largest drop between December and January on record. 

However, the 2.05 million birds is 11% higher than last January’s estimate of 1.85 million, but it’s 25% lower than the most recent five-year average of 2.75 million, and 32% below the long-term average of 3.01 million.

“All species declined from the December survey except for mottled ducks and shovelers, with the biggest proportional differences seen in mallards (196,000 to 81,000), gadwalls (1,008,000 to 477,000), ring-necked ducks (765,000 to 404,000), canvasbacks (300,000 to 166,000), and green-winged teal (805,000 to 481,000),” Reynolds wrote in his report. “Despite big declines from December, estimates for ring-necked ducks and canvasbacks remain well above their long-term January averages of 183,000 and 73,000 respectively, while all other species were below or far below their January averages.”

Two factors could have played into January’s low number for 2017. 

Reynolds noted that hunters reported birds ‘disappearing’ in the warm weather of late-December, and when this survey was flown, rainfall had flooded most of the coastal marsh and provided extensive habitat in agricultural fields within and north of the survey area.

Also, weather extremes during the actual survey period could have played a part in the low numbers as well, Reynolds noted.

“The coastal transects were completed prior to the hard freeze of Jan. 6-8, and unseasonably warm temperatures have dominated since then while the other surveys were being conducted,” Reynolds wrote. “Impacts of that remain speculative.”

Ducks in coastal habitats apparently shifted west since December, with 61% of ducks counted in January being seen in Southwest Louisiana.

“Similar to December, the bulk of diving ducks were counted in Southeast Louisiana with the large majority of dabbling ducks counted in the Southwest.  The largest concentration of ducks  in Southwest Louisiana were on the open water of White Lake, agricultural fields southwest of Gueydan, and a sewage lagoon near Rayne,” Reynolds wrote. “In Southeast Louisiana, the biggest concentration of ducks was seen in the upper Terrebonne marshes, but far fewer ring-necked ducks were seen in that location than in December.  

“Presumably, weather and associated habitat conditions stimulated a redistribution of ducks from surveyed coastal habitats.”

One bright spot was Catahoula Lake, where 237,000 ducks were counted in January.

“Big increases in ring-necked ducks (58,000 to 79,000) and canvasbacks (61,000 to 158,000) since the December survey generated a January total that is the highest since 2004, when 291,000 total ducks were counted,” Reynolds wrote. “Water depth remains within target levels, and moist-soil vegetation growth this summer was better than in recent years, so habitat conditions remain very good.”

Reynolds said recent mid-winter waterfowl surveys in neighboring states show conflicting results.

“Arkansas’s early-January duck populations remain below average with mallards at the lowest levels since 2010,” he wrote. “In contrast, Mississippi’s early-January survey estimated over 1.4 million ducks compared to 500,000-600,000 in January of the prior two years.”