Search USGS⌕ Search
Home/Archive/USGS

USGS · 1016414

The value of agricultural wetlands as invertebrate resources for wintering shorebirds

Oriane W. Taft·Susan M. Haig
View original source ↗Export metadata ↓

Abstract

Agricultural landscapes have received little recognition for the food resources they provide to wintering waterbirds. In the Willamette Valley of Oregon, modest yet significant populations of wintering shorebirds (Charadriiformes) regularly use hundreds of dispersed wetlands on agricultural lands. Benthic invertebrates are a critical resource for the survival of overwintering shorebirds, yet the abundance of invertebrate resources in agricultural wetlands such as these has not been quantified. To evaluate the importance of agricultural wetlands to a population of wintering shorebirds, the density, biomass, and general community composition of invertebrates available to birds were quantified at a sample of Willamette Valley sites during a wet (1999–2000) and a dry winter (2000–2001). Invertebrate densities ranged among wetlands from 173 to 1925 (mean ± S.E.: 936 ± 106) individuals/m 2 in the wet winter, and from 214 to 3484 (1028 ± 155) individuals/m 2 in the dry winter. Total invertebrate estimated biomass among wetlands ranged from 35 to 652 (mean ± S.E.: 364 ± 35) mg/m 2 in the wet winter, and from 85 to 1405 (437 ± 62) mg/m 2 in the dry winter. These estimates for food abundance were comparable to that observed in some other important freshwater wintering regions in North America.

Explore related subjects

Agriculture, Ecosystems and EnvironmentArticle

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Oriane W. Taft, Susan M. Haig. 2005. The value of agricultural wetlands as invertebrate resources for wintering shorebirds. https://doi.org/10.1016/j.agee.2005.04.012

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related USGS reports

USGS2024

Bird community response to field-level integration of prairie strips

Grassland birds are under threat worldwide due to loss of habitat to agriculture. Prairie strips are a new agricultural conservation practice composed of linear strips of reconstructed diverse, native, herbaceous, perennial vegetation designed to promote land sharing among agriculture and biodiversity, while also addressing soil and water conservation goals. We evaluated bird community response to establishment of prairie strips on commercial row-crop fields (corn [( Zea mays ] and soybean [ Glycine max ]) in Iowa, USA compared to controls fields without prairie strips, from 2015 to 2020. We found a 2.94-fold higher density of grassland birds on fields with prairie strips compared to control fields, and a 1.87-fold higher density of birds overall. Time since prairie strip establishment was a significant predictor of grassland bird density, with significant increases between years 1 and 2 and years 3 and 4. Species with the strongest positive response to prairie strips were Red-winged Blackbird ( Agelaius phoeniceus ), Common Yellowthroat ( Geothlypis trichas ), Western Meadowlark ( Sturnella neglecta ) and two species of greatest conservation need: Dickcissel ( Spiza americana ) and Eastern Meadowlark ( Sturnella magna ). Diversity measures (e.g., Shannon’s and Simpson’s indices) did not differ between fields with prairie strips versus those without. Prairie strips provide quality breeding habitat for a suite of species, including grassland species and those of conservation concern. While improving several bird community measures, prairie strips do not provide habitat for area-sensitive grassland birds. Larger grassland patches are needed, potentially managed as land-sparing reserves, to achieve overall biodiversity goals in agricultural landscapes.

Iowa↗
USGS2021

The influence of floral resources and microclimate on pollinator visitation in an agro-ecosystem

As agriculture expands to meet the needs of a growing global population, natural ecosystems are threatened by deforestation and habitat fragmentation. Tropical agroforestry systems offer a sustainable alternative to traditional agriculture by providing food for production while also supporting biodiversity and ecosystem services. Previous studies have shown that these systems may even improve crop pollination, but the mechanisms of how these improvements occur are still poorly understood. Using coffee as a focal crop, we explored how microclimatic conditions affected nectar traits (sugar and caffeine concentration) important for pollinator visitation. We also studied how microclimate, floral traits, floral availability at the coffee plant level, availability of floral resources provided by other plant species in the agroecosystem (neighborhood floral availability), and the presence of other bees affected the amount of time bees spent foraging on coffee flowers and the proportion of coffee pollen carried on their bodies. We explored these factors using the two dominant coffee species farmed on Puerto Rico, Coffea canephora and C. arabica , under sun and shade management. We found that high nectar sugar concentration and temperature were important predictors of short floral visits (<15 seconds), while increased number of bees and open coffee flowers were important predictors of longer floral visits (16-180 seconds). High nectar caffeine concentration was an important predictor of longer visits on C. arabica flowers while the opposite was observed for C. canephora flowers. For both species, high coffee floral availability was the main predicting factor for the proportion of coffee pollen on the bees bodies. Surprisingly, neither neighborhood floral availability nor the type of coffee plantation (agroforest/shade or sun) were important predictors of bee visitation. These results suggest non-coffee flowering plants in coffee plantations were neither competitors nor facilitators of coffee plantes for pollinators. Additionally, most of the bees surveyed were carrying 80% pollen from one species ( C. arabica or C. canephora ), likely resulting in little heterospecific pollen deposition between Coffea and non-Coffea flowers. Shade trees in coffee plantations do not detract from pollinator visitation to coffee flowers, suggesting that the provision of multiple ecological and wildlife conservation benefits by shade trees is not in conflict with a growers ability to maximize the benefits of insect pollination on fruit production.

Adjuntas Lares,Las Marias, Maricao, Puerto Rico Ut↗
USGS2020

Neonicotinoid insecticide concentrations in agricultural wetlands and associations with aquatic invertebrate communities

Neonicotinoids are considered a superior insecticide for agricultural pest management, although their impacts on non-target insects is a rising concern. Aside from laboratory and mesocosm studies, limited research has been directed towards the role neonicotinoids may have in structuring aquatic invertebrate communities in field settings. Therefore, we simultaneously collected aquatic invertebrate and surface water samples from 26 wetlands within a highly modified agricultural landscape of Nebraska’s Rainwater Basin during spring 2015. Water samples were tested for six different neonicotinoids, nutrients, and physical properties. Trace levels of clothianidin and imidacloprid were the only neonicotinoids detected, occurring in 85% and 15%, respectively, of wetlands sampled. All measurements for clothianidin and imidacloprid were below chronic toxicity benchmarks set by the United States Environmental Protection Agency. Neonicotinoid concentrations were significantly lower (W 26, 0.05 = 42.5) at wetlands with vegetative buffer strips > 50 m wide compared to wetlands with vegetative buffers strips <50 m. Although neonicotinoids were below benchmark concentrations proposed by government regulations, a significant negative association between neonicotinoid concentrations and aquatic invertebrate biomass was observed across all wetlands studied (Parameter Estimate = -0.031; SE = 0.014).

Nebraska↗