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Summary 0[ Recent legislation designed to reduce air pollution has restricted Californian rice! farmers from burning rice stubble after harvest[ Intentional~ooding of _elds during winter to speed straw decomposition is becoming increasingly common as growers seek alternatives to burning residual straw[ The potential for~ooded _elds to act as a surrogate for destroyed wetland habitat may be an additional bene_t in a region that hosts a large proportion of North America|s wintering waterbirds[ We investigated the degree to which waterbirds use~ooded _elds and whether the method of~ooding a}ects their use[ Speci_cally\ we tested whether waterbird use "a# was greater in intentionally~ooded _elds than in un~ooded _elds\ "b# di}ered among~ooded _elds receiving di}erent straw manipulations and "c# varied with water depth[ 1[ Intentionally~ooded rice _elds received signi_cantly greater use by 13 of 20 species studied[ Only great blue herons Ardea herodias and sandhill cranes Grus canadensis were signi_cantly more common in un~ooded _elds[ Geese densities did not di}er between~ooded and un~ooded _elds[ 2[ We found no di}erences in the densities of most species in~ooded _elds that received di}erent straw manipulations to improve decomposition rates[ Exceptions included several small shorebirds which occurred at highest densities in _elds where straw was incorporated into the soil[ 3[ Species di}ered in their use of di}erent water depths[ For 03 species we tested whether preferred depths\ suggested in the literature\ received disproportionately higher use[ Most of these species were more likely to be encountered within the suggested depth ranges[ Depth\ however\ was a poor predictor of bird density[ Depths of 04Ð19 cm resulted in frequent use by the greatest number of species[ 4[ We conclude that~ooding rice _elds increased suitable habitat for most\ but not all\ species studied[ Di}erent straw manipulation methods had little e}ect on most species[ Water depth\ however\ was important in determining species occurrence[ During the _rst half of the winter\ water depths were greater than the median depths used by most species[ Key!words] agriculture\ shorebirds\ waterfowl\ water depth\ wetland management[

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The current conservation crisis calls for research and management to be carried out on a longterm, multi-species basis at large spatial scales. Unfortunately, scientists, managers, and agencies often are stymied in their effort to conduct these large-scale studies because of a lack of appropriate technology, methodology, and funding. This issue is of particular concern in wetland conservation, for which the standard landscape approach may include consideration of a large tract of land but fail to incorporate the suite of wetland sites frequently used by highly mobile organisms such as waterbirds (e.g., shorebirds, wading birds, waterfowl). Typically, these species have population dynamics that require use of multiple wetlands, but this aspect of their life history has often been ignored in planning for their conservation. We outline theoretical, empirical, modeling, and planning problems associated with this issue and suggest solutions to some current obstacles. These solutions represent a tradeoff between typical in-depth single-species studies and more generic multi-species studies. They include studying within-and among-season movements of waterbirds on a spatial scale appropriate to both widely dispersing and more stationary species; multi-species censuses at multiple sites; further development and use of technology such as satellite transmitters and population-specific molecular markers; development of spatially explicit population models that consider within-season movements of waterbirds; and recognition from funding agencies that landscape-level issues cannot adequately be addressed without support for these types of studies. Movimientos de Aves y Conectividad de Humedales en la Conservación del PaisajeResumen: La actual crísis en la conservación exige de investigación y manejo a desarrollarse en escalas de largo plazo, basada en multiples especies y en espacios grandes. Desafortunadamente, los científicos, manejadores y las agencias frecuentemente ven frustrados sus esfuerzos para conducir estos estudios de gran escala debido a la carencia de tecnología, metodologia y soporte económico apropiados. Este tema es de particular interés en la conservación de humedales donde la perspectiva común de paisaje pudiera considerar un área extensa de tierra pero no incorpora humedales aptos que son frecuentemente usados por organismos con alta movilidad como lo son las aves acuáticas (aves playeras o de vados, ganzos, patos). Tipicamente estas especies tienen dinámicas poblacionales que requiren del uso de multiples humedales, sin embargo, este aspecto de su historia de vida frecuentemente es ignorado en la planeación de su conservación. Resaltamos problemas teóricos, empíricos, de modelado y de planeación asociados con este tema y sugerimos soluciones para algunos obstáculos actuales. Estas soluciones representan un intercambio entre estudios a profundidad de una sola especie y estudios genéricos multiespecie. Estos últimos incluyen el estudio de movimientos de las aves acuáticas entre y dentro estaciones en una esc...