Functional Equivalency between Rice Fields and Seminatural Wetland Habitats

摘要: : Evaluating the potential for anthropogenic habitats to act as surrogates natural they replace is a key issue in conservation biology. In California, flooded rice fields are used by numerous aquatic birds during winter. If this habitat functions similarly more wetlands, increased flooding may help extensive wetlands that occurred region prior agricultural development. I tested whether food abundance, perceived predation threat, foraging performance, and way which allocate their time different behaviors differed between seminatural several species of bird. When appropriate, also compared unflooded fields. Invertebrate densities did not differ among habitats. Seminatural had less grain but seeds from other plants than two The frequency with predators passed over feeding area was lower or wetlands. Most differences performance allocation were small statistically insignificant. For some species, efficiency greater Increasing attack rates amount spent when fields, however, allow compensate reduced efficiency. Multivariate analyses showed group size, day, date, water depth often associated behaviors, these variables rarely accounted differences. Flooded apparently provide equivalent and, because be safer waterbirds. Thus, if managed appropriately, one world's dominant forms agriculture can valuable waterbird habitat. Resumen: La evaluacion del potencial en antropogenicos para actuar como substitutos de los naturales que remplazaron es un tema clave la biologia conservacion. En tierras inundadas cultivo arroz son utilizadas por numerosas aves acuaticas durante el invierno. Si estos funcionan forma similar humedales mas naturales, incremento inundaciones podria ayudar reemplazar extensos existieron antes desarrollo agricultural. Analize si abundancia alimento, percepcion peligro depredacion, rendimiento forrajeo y las distribuyen su tiempo hacia diferentes conductas difieren entre arrozales inundados seminaturales especies acuaticas. Cuando fue posible, tambien compare contra no inundados. Las densidades invertebrados difirieron Los tuvieron menos grano arroz, pero semillas otras plantas dos tipos arrozal. frecuencia con depredadores pasaron sobre alimentacion menor campos o seminaturales. mayoria diferencias alimenticio dedicado pequeno estadisticamente insignificante. Para algunas especies, eficiencia alimenticia mayor Sin embargo, tasas ataque cantidades utilizado cuando estaban permitir compensar esta reducida eficiencia. Un analisis multivariado mostro tamano grupo, hora dia, fecha profundidad agua estuvieron frecuentemente asociados conductas, estas raramente aportaron elementos encontrar aparentemente proveen equivalente debido amenaza podrian ser seguro Por lo tanto, manejados adecuadamente, una formas dominantes agricultura nivel mundial puede proporcionar valioso