We were unable to complete the survey in coastal Louisiana, missing 4 transects in the southeast region, due to poor weather September 9-11. Scattered storms also created sub-optimal conditions for completed portions of the survey. In most cases when the survey is incomplete, a report is not generated because overall survey numbers are not directly comparable to past years or averages.
However, changes from September 2008 in both waterfowl abundance over portions of the surveyed area and habitat conditions across the entire area warrant this report.
The 145,000 ducks estimated on this survey in southwest Louisiana is far less than the 473,000 estimated in September 2008 despite substantially more mottled ducks being seen (45,000 vs 28,000). The 99,000 blue-winged teal seen in this region is less than one-quarter the 444,000 seen last year. Last year was extraordinary because the long-term average for bluewings over the entire survey area is 252,000. The distribution of bluewings in southwest Louisiana was similar to 2008 with the majority seen in flooded agriculture fields north of the marsh at Lacassine NWR east to Kaplan.
We also estimated 14,000 black-bellied and 8,000 fulvous whistling ducks on this survey, all in southwest Louisiana. Most were seen near the marsh/agricultural boundary from Lacassine NWR east to Intracoastal City.
In contrast to southwest Louisiana, and although we missed 4 of the 10 lines in southeast Louisiana, the estimated number of bluewings there was 3 times that of 2008. Almost all of those were seen in the marshes near the mouth of the Mississippi River as 4 of the 5 transects west of that line were not completed. Despite the incomplete survey, more mottled ducks were seen in southeast Louisiana than in 2008 as well.
At Catahoula Lake, we counted 9,000 bluewings compared to zero in 2008. Habitat conditions are much improved over last year, when September hurricane floodwaters inundated existing vegetation and eliminated most waterfowl food produced on the Lake. This year, good production of waterfowl food-plants was evident from the airplane.
Habitat conditions in the marshes of coastal Louisiana also looked much improved from September 2008, when hurricanes Gustav and Ike caused severe damage to marsh vegetation. In southwest Louisiana marshes, there are broad expanses of seed-producing annual vegetation such as millets, pigweeds, and panic grasses in many locations, especially between Calcasieu Lake and Vermilion Bay. Although the submerged aquatic growth appears below-average, the extensive production of annual vegetation should provide an excellent food source for migrating and wintering ducks if water levels are near normal. We noted low water levels in the marsh including extensive dry areas in some locations and only managed water in the agricultural areas, which is normal in September.
In southeast Louisiana, we saw good submerged aquatic vegetation growth in most areas. Excellent growth was noted in upper Terrebonne Parish and in the marshes near the mouth of the Mississippi River. So it appears that habitat conditions for waterfowl are improved from 2008 barring any major storm events.
