The value of agricultural wetlands as invertebrate resources for wintering shorebirds

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 AE S.E.: 936 AE 106) individuals/m 2 in the wet winter, and from 214 to 3484 (1028 AE 155) individuals/m 2 in the dry winter. Total invertebrate estimated biomass among wetlands ranged from 35 to 652 (mean AE S.E.: 364 AE 35) mg/m 2 in the wet winter, and from 85 to 1405 (437 AE 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. Published by Elsevier B.V.

Patterns of Waterbirds Abundance and Habitat Use in Rice Fields

“…6 and Table 1). 이는 벼의 성장으로 인해 본 답의 접근성이 떨어지기 때문에, 보다 쉽게 먹이를 사냥할 수 있는 곳을 이용하기 때문이다 (Toral et al, 2011), 주로 물댄 논의 바닥층과 수중에 서식하는 저 서무척추동물을 먹이 자원으로 이용한다 (Taft and Haig, 2005). 논은 본답, 수로, 논둑, 농로 등 각기 독특한 형태의 미소 서식지로 구성되어 있으며, 각각의 특성에 따라 수조류의 이 용 특성이 다르게 나타난다 (Narusue and Uchida, 1993;Lane and Fujioka, 1998;Maeda, 2001).…”

Agricultural ponds as alternative habitat for waterbirds: spatial and temporal patterns of abundance and management strategies

“…Salt marshes, aquaculture fish ponds, mine impoundments, gravel pits, rice fields or irrigation ponds are able to provide alternative or substitute habitats for waterbirds communities as well as for amphibians (Knutson et al 2004;Julian et al 2006) plants or invertebrates (Nicolet et al 2004;Taft and Haig 2005;Abellán et al 2006).…”

“…Almost half the world's wetlands have disappeared in the last century due to agricultural and urban development (Shine and Klemm 1999). Therefore, waterbirds may benefit from using alternative places to feed and breed, even if these spaces are man-made.…”

Use of Aquaculture Ponds and Other Habitats by Autumn Migrating Shorebirds Along the Lower Mississippi River

“…However, we did not observe any shorebirds other than Killdeer using agricultural habitats in our standardized random surveys; low densities of other shorebird species were observed in our incidental agricultural surveys. Agricultural areas have been demonstrated to be important to shorebirds during the non-breeding season and during spring migration (Taft and Haig 2005;Niemuth and others 2006;Ogden and others 2008); in the LMAV, flooded soybean and rice fields were heavily used by Killdeer and Wilson's Snipe from November to March (Twedt and others 1998). In addition, preferential use of agricultural land at night was observed by Dunlins (Caladris alpina) in British Columbia (Shepherd and others 2003); indicating diurnal surveys may underestimate the importance of agricultural habitat to shorebirds.…”