Bruce, it is very likely there is an abundance of scuds in my brothers wetland, the ducks seem to prefer it to all other wetalnds in the area, it happens to be one of those rare never been plowed wetlands with huge amount of biodiversity.
Here is an intersting read on lesser scaup and amphipods:
Wetland use by scaup was positively correlated with amphipod densities throughout the upper-Midwest, indicating a preference for amphipods. Amphipod densities were markedly lower (1 – 12 m-3) and scaup were consuming fewer amphipods in the upper-Midwest relative to historical records. Scaup probably must spend more time searching for food within and among wetlands than they did historically. Fish occurred in 74, 78 – 84, and 31 – 45% of wetlands in Iowa, Minnesota, and North Dakota, respectively, whereas historically they occurred in only 10 – 20% of wetlands. Amphipod densities were negatively correlated to fish densities and sedimentation.
If scuds are not prevelent in his wetland I would be very suprised. It could also be a great place to stock scuds and then harvest them later.
Although invertebrates occur in wetlands everywhere, prairie wetlands support notably great numbers. This is because prairie wetlands have especially rich soils, slow water turnover times, and seasonally fluctuating water tables, all of which support the high levels of algal production and spatially complex vegetative stands that are important to invertebrates.
Quote:
In some cases, waterbirds appear to select wetlands having the greatest densities of invertebrates (Talent et al. 1982).
So, scud hunting is likely best in fishless wetlands that have deep enough water year round.
