Managed moist-soil units support early succession herbaceous vegetation that produces seeds, tubers, and other plant parts used by waterfowl in the Mississippi Alluvial Valley (MAV), USA. We conducted a stratified multi-stage sample survey on state and federal lands in the MAV of Arkansas, Louisiana, Mississippi, and Missouri during autumns 2002–2004 to generate a contemporary estimate of combined dry mass of seeds and tubers (herein seed abundance) in managed moist-soil units for use by the Lower Mississippi Valley Joint Venture (LMVJV) of the North American Waterfowl Management Plan. We also examined variation in mean seed abundance among moist-soil units in 2003 and 2004 in relation to management intensity (active or passive), soil pH and nutrient levels, proportional occurrence of plant life-forms (e.g., grass, flatsedge, and forb; vine; woody plants), and unit area. Estimates of mean seed abundance were similar in 2002 (&#x1d465; = 537.1 kg/ha, SE = 100.1) and 2004 (&#x1d465; = 555.2 kg/ha, SE = 105.2) bu...

Moist-Soil Seed Abundance in Managed Wetlands in the Mississippi Alluvial Valley

. Worldwide, rice (Oryza sativa) agriculture typically involves seasonal flooding and soil tillage, which provides a variety of microhabitats and potential food for birds. Water management in rice fields creates conditions ranging from saturated mud flats to shallow (<30 cm) water, thereby attracting different guilds of birds. Grain not collected during harvest (i.e. waste rice) is typically the most abundant potential food of birds in rice fields, with estimates of seed mass from North America ranging from 66–672 kg/ha. Although initially abundant after harvest, waste rice availability can be temporally limited. Few abundance estimates for other foods, such as vertebrate prey or forage vegetation, exist for rice fields. Outside North America, Europe and Japan, little is known about abundance and importance of any avian food in rice fields. Currently, flooding rice fields after harvest is the best known management practice to attract and benefit birds. Studies from North America indicate specific ...

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Avian Foods, Foraging and Habitat Conservation in World Rice Fields

The fate of lakes in the Illinois River valley / Bio Notes No. 119

Habitat conservation strategies of the North American Waterfowl Management Plan (NAWMP) are guided by current understanding of factors that limit growth of waterfowl populations. The 1998 implementation plan of the Upper Mississippi River and Great Lakes Region Joint Venture (UMR and GLRJV) assumed that availability of foraging resources during autumn in wetlands actively managed for waterfowl was the primary limiting factor for duck populations during the nonbreeding season. We used multistage sampling during autumn and spring 2001–2004 to estimate energetic carrying capacity (ECC) of actively and passively managed wetlands in Ohio, USA, and examine this assumption. Energetic carrying capacity during autumn was similar between actively and passively managed wetlands each year. Averaged across years, energetic carrying capacity was 3,446 and 2,047 duck energy-days (DED)/ha for actively and passively managed wetlands, respectively. These estimates exceeded the UMR and GLRJV assumption that 1,236 D...

https://www.jstor.org/stable/info/4496373

Energetic carrying capacity of actively and passively managed wetlands for migrating ducks in Ohio

Altered hydrology resulting from the presence of locks and dams and erosive agricultural land use practices have created conditions that have impacted the growth, distribution, and survival of aquatic vegetation on the Upper Mississippi River System (UMRS). Three inter-related abiotic factors (light transparency, nutrients, and sedimentation) worsened by impoundment and erosive agricultural practices, have played a major role in widespread submersed macrophyte loss in the UMRS. Aquatic vegetation provides food and shelter for biota as well as impacting water quality. Successful efforts to restore aquatic macrophytes on the UMRS have focused on habitat restoration construction projects and water-level management drawdowns. Currently, the status of aquatic vegetation varies within the UMRS, with most of the aquatic vegetation being found between lower Pool 4 (below Lake Pepin) and Pool 13. Although aquatic macrophytes have varied among locations over the past 17 years, an increase in aquatic plants was apparent in 2007 and 2008. Very little research regarding the role of moist soil and emergent vegetation and their responses to ecological factors has occurred within the UMRS. Future research efforts must continue to focus on understanding the ecological and anthropogenic impacts to all aquatic macrophytes within the landscape of one of the largest river systems in the world.

Synthesis of Upper Mississippi River System submersed and emergent aquatic vegetation: past, present, and future

The Illinois River Valley (IRV) is a critical ecoregion for migratory waterfowl. Significant wetland loss occurred in this region in the early 20th Century, and remaining wetlands are subject to additional degradation via sedimentation, summer flooding from the Illinois River and invasive species. Managed moist-soil wetlands may provide quality foraging habitat for migrating waterfowl, but contemporary estimates of seed production and carrying capacity do not exist for the IRV. We evaluated seed production and carrying capacity of a 931-ha moist-soil wetland at Chautauqua National Wildlife Refuge in central Illinois during falls 1999–2001. Seed production varied annually (329–1231 kg/ha), but overall was greater than previously published estimates for other areas of North America. Estimated carrying capacity across years was 6.760 ± 411 (se) duck use-days/ha; this value was 1.5–15.4 times greater than other published carrying capacity estimates for harvested corn, rice and soybeans. We recommend ...

Moist-soil Plant Seed Production for Waterfowl at Chautauqua National Wildlife Refuge, Illinois

The number of Mallards (Anas platyrhynchos) breeding in Illinois and eastern North America has increased in recent decades; however, few studies have investigated the nesting biology of Mallards outside primary production areas. Therefore, we radiomarked resident female Mallards (n = 148) in west-central Illinois during 1998–2003 to assess nesting parameters and evaluate recruitment. Mean initiation date for first nests ranged from 22 April to 6 May, and the majority (75%) of nests were initiated by 20 May. Therefore, the majority of nests were predicted to hatch by 24 June. The nesting season averaged 88 days (range: 77–103 days). The proportion of unsuccessful females that renested ranged from 50.0–85.7%, and adults were more likely to renest (75.0%) than yearlings (48.0%). Nest success ranged from 9.8–33.3% and was 19.6% overall; hen success was 28.3%. Initial brood size was 8.2 ± 0.3 ducklings, but brood size declined to 3.0 ± 0.6 ducklings by 17 days posthatch. Brood survival to 20 days was 0.759 ± 0.081, and 20-day duckling survival was 0.413 ± 0.035. Female survival during spring-summer ranged from 0.546–1.00 and averaged 0.710 ± 0.096. Likewise, estimated Mallard recruitment varied annually (range: 0.302–0.672 female ducklings/female). Assuming constant female and duckling survival, we estimated that a recruitment rate of 0.613 female ducklings/adult female was necessary to maintain a stable Mallard breeding population in west-central Illinois. Estimated Mallard reproduction and recruitment was similar to that observed in other areas of North America. Nest success and hen success approached or exceeded estimated thresholds for population stability in most years; however, hen success averaged over the study period was insufficient for local population maintenance and growth. Female survival was comparable to that observed in other studies but may have limited population growth in some years. Duckling survival was sufficient for population maintenance. Management designed to enhance hen success and brood habitat may augment Mallard recruitment in west-central Illinois.

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Matthew W. Bowyer

Papers

Moist-soil Plant Seed Production for Waterfowl at Chautauqua National Wildlife Refuge, Illinois

Nesting Biology of Mallards in West-central Illinois