Agriculture as matchmaker of an unexpected mutualism: Great bustard disperses and enhances emergence of domestic olive seeds

By changing the habitats and altering plant traits, agriculture has severely disrupted many plant–animal mutualisms. Interest- ingly, however, the intensification of agricultural practices could also facilitate mutualistic relationships between species with naturally mismatching phenotypes. We illus...

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Detalles Bibliográficos
Autores: Delibes, M., Corbacho, Casimiro, Calvo, Gemma, Fedriani, José M.
Tipo de recurso: artículo
Fecha de publicación:2012
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/50229
Acceso en línea:http://hdl.handle.net/10261/50229
Access Level:acceso abierto
Palabra clave:Artificial selection
Fruit size
Habitat shaping
Mediterranean habitat
Old-field recolonization
Olea europaea
Seed dispersal
Descripción
Sumario:By changing the habitats and altering plant traits, agriculture has severely disrupted many plant–animal mutualisms. Interest- ingly, however, the intensification of agricultural practices could also facilitate mutualistic relationships between species with naturally mismatching phenotypes. We illustrate the potential of the great bustard (Otis tarda), a large steppe bird, as disperser of domestic olive (Olea europaea) seeds, originally a forest species. In an area of southwestern Spain, 30% of bustard faeces included olive stones (from 1 to 13). Only 1.7% of the bustard-ingested olive seeds were broken. Moreover, using a sowing experiment, we show bustard ingestion enhanced seedling emergence, which reached 8.8%, 3.4% and 0.0% for bustard-ingested, hand-depulped, and control seeds, respectively. As expected for Mediterranean habitats, seedling mortality was very high in the first summer for all seed treatments. In 6 out of 19 non-plowed patches within our study area, we found olive saplings of different ages likely to emerge from bustard-dispersed seeds. Given the large size of domestic olive fruits, bustards are among the few local animals able to disperse their seeds and thus to assist in the forestation of field boundaries and abandoned lands. Paradoxically, because bustards are rather restricted to open habitats, their success in shaping the habitat (i.e., ‘planting’ olive trees) could lead to their own removal from the resulting forested landscape