A history of ecological studies of birds in rice fields

Abstract

Birds have been studied in rice fields for over a century. Early studies focused on species directly linked to crop production, either because they were considered to be crop pests or because they preyed upon undesirable species found in fields. Prior to 1970, most studies focused on waterfowl, with a majority coming from North America. This taxonomic and geographic bias persisted into the 1980s, when research began to diversify along multiple axes. Work on birds in rice fields has expanded on all continents, but is dominated by studies from Asia, Europe, and North America. Although Asian studies have become more numerous, they remain substantially fewer than expected given the geographic distribution of rice production. Studies from Africa are also less common than expected on the basis of the area of rice grown. Taxonomically, studies of large wading birds are now most numerous, although waterfowl research remains common. Studies of other taxonomic groups have also increased, as has research that examines the avian community more broadly by considering birds from multiple taxonomic groups. Landbird studies peaked in the 1990s with a focus on controlling crop depredation, but remain rare otherwise. Most research remains centered on waterbirds, despite evidence of rice field use by a diversity of passerines, raptors, and other landbirds. Research also has been dominated by descriptive studies, usually with an applied focus. Ornithologists, however, are beginning to recognize the high potential of rice field systems for conducting more experimental studies and for testing a wider variety of basic ecological questions.