A global overview of the conservation, management and research of the world's waterbird flyways

Rice is the second most important crop in Cuba. The main plantations are along the south coast, near natural wetlands. Because rice fields are seasonal and temporary wetlands, they may have an important role as substitute habitat for waterbirds. We studied the bird community associated with rice culture in several plantations in Cuba, and found that 70 bird species were using the paddies mainly as feeding areas, and consuming about 46 different food items. Migrant birds (mainly ducks and shorebirds) comprised 74% of the birds reported; 37% were winter migrants and 37% were species with resident and migratory populations. Most waterbirds utilize both paddies and coastal wetlands as wintering sites. Habitat use during the rice cycle was determined for each of the main guilds in the bird community. The daily consumption of the bird community was determined throughout the year and the rice cycle. In winter, because of the influence of the migrant duck population, daily consumption was five times greater than in summer. We concluded that rice-farming areas in Cuba are playing a key role in the conservation of migratory waterbirds in winter. Cooperative efforts are necessary to understand the complex ecological interactions that are taking place in the paddies and to enhance this important waterbird habitat. INTRODUCTION Rice paddies are among the most productive and dependable agricultural systems devised by humans (Odum 1993), and may be important ecological areas acting as alternative habitat for wetland wildlife (Fasola & Ruíz 1997). Alternating periods of flooding and drying during the rice-growing cycle create a structurally complex habitat which retains many features typical of natural ecosystems. Because waterbirds, with their specific habitat requirements, may be most likely to use those newly created habitats which are most similar to their natural habitat (Cody 1981), the unusually high degree of structural complexity of the rice agro-ecosystem should promote high avian diversity, especially in areas with low usage of pesticides. After sugar cane, rice is the crop occupying the second highest acreage in Cuba, where it is grown in five provinces. Because of the shape of the island, most of the rice-growing areas are near the south coast. In most places, the coastal belt between the rice fields and the sea is natural wetland, and so the coastal wetlands and paddies may act as a conservation unit for waterbirds. Furthermore, there has been a drastic reduction in the use of chemicals by Cuban farmers in recent years because of the economic crisis, with a consequent increase in the availability of food for waterbirds in the rice-growing areas. The importance of these areas for wintering waterbirds is enhanced by the fact that Cuba is in the middle of two important bird migration corridors, the Atlantic and the Mississippi flyways. Thus, Cuba is not only an important wintering area for migrants from North America, but also a very important staging area for birds that are migrating further south. The rice-growing areas may play a key role in the conservation of these species (Mikuska et al. 1998). Although the cultivation of rice is an ancient agricultural practice and rice is now considered the second most important crop in the world (Hoffman 1993), relatively little attention has been given to the complex interactions between the bird community and the rice crop. Some recent studies include those by Fasola & Ruíz (1996), Day & Collwell (1998), Elphick & Oring (1998), Elphick (2000) and Tourenq et al. (2001). Using all of the information collected during a decade (1992-2003) of field studies by the Bird Ecology Group of the University of Havana, our main aims in this paper are: firstly, to summarize data on the diversity, abundance and habitat use of migratory waterbirds using rice fields in Cuba; and secondly, to draw attention to the need for an integrated approach to rice farming that will take into consideration its importance in the conservation of migratory waterbirds. STUDY AREAS The rice-growing regions are huge (c. 20 000 ha), flat areas, usually divided into fields of one hectare. Along the south coast, there is usually a 1 to 5 km wide belt of natural coastal wetlands between the paddies and the sea. During the rice cycle, the development of the rice plant changes with the water regime, and eight different field types have been identified on the basis of water level and vegetation cover (Mugica et al. 2003). Samples of the birds using each of these eight field types were taken separately. As the sowing period is spread over several months, many different field types are available at any one time. METHODS We compiled published and unpublished information on the importance of rice fields for migrant birds in Cuba. Most data were collected between 1992 and 2000 during a study of the bird community in the Sur del Jíbaro rice fields in Sancti Spiritus, Cuba (21 ̊35’-21 ̊45’N, 79 ̊5’-79 ̊25’W). Additional data were gathered by sampling the coastal wetlands associated with the rice-growing areas and two other rice-growing areas: Los Palacios, Pinar del Río, in western Cuba, and Amarillas Rice Culture, Matanzas, in central Cuba. In order to estimate densities of waterbirds and habitat use, the counts were conducted during the first four hours after sunrise (the period of maximum bird activity and relatively low air temperatures) by walking along two transects in each field using a stratified sampling method (each of the eight stages of Rice culture in Cuba as an important wintering site for migrant waterbirds from North America Lourdes Mugica1, Martín Acosta1, Dennis Denis1, Ariam Jiménez1, Antonio Rodríguez1 & Xavier Ruiz2 1 Universidad de la Habana, Facultad de Biología, 25 e J e I Vedado, Ciudad Habana, Cuba. (email: lmugica@fbio.uh.cu) 2 Universitat de Barcelona, Dept. de Biologia Animal. Av. Diagonal 645, 08028-Barcelona, Spain. Mugica, L. , Acosta, M. , Denis, D. , Jiménez, A. , Rodríguez, A. & Ruiz, X. 2006. Rice culture in Cuba as an important wintering site for migrant waterbirds from North America. Waterbirds around the world. Eds. G.C. Boere, C.A. Galbraith & D.A. Stroud. The Stationery Office, Edinburgh, UK. pp. 172-176.