title: Endangered plant-parrot mutualisms: seed tolerance to predation makes parrots pervasive dispersers of the Parana pine.
abstract: Parrots are largely considered plant antagonists as they usually destroy the seeds they feed on. However, there is evidence that parrots may also act as seed dispersers. We evaluated the dual role of parrots as predators and dispersers of the Critically Endangered Parana pine (Araucaria angustifolia). Eight of nine parrot species predated seeds from 48% of 526 Parana pines surveyed. Observations of the commonest parrot indicated that 22.5% of the picked seeds were dispersed by carrying them in their beaks. Another five parrot species dispersed seeds, at an estimated average distance of c. 250 m. Dispersal distances did not differ from those observed in jays, considered the main avian dispersers. Contrary to jays, parrots often dropped partially eaten seeds. Most of these seeds were handled by parrots, and the proportion of partially eaten seeds that germinated was higher than that of undamaged seeds. This may be explained by a predator satiation effect, suggesting that the large seeds of the Parana pine evolved to attract consumers for dispersal. This represents a thus far overlooked key plant-parrot mutualism, in which both components are threatened with extinction. The interaction is becoming locally extinct long before the global extinction of the species involved.
authors.affiliation: Department of Conservation Biology, Estación Biológica de Doñana, CSIC. Américo Vespucio s/n, E-41092 Sevilla, Spain.
authors.forename: José L
authors.initials: JL
authors.lastname: Tella
authors.affiliation: Department of Conservation Biology, Estación Biológica de Doñana, CSIC. Américo Vespucio s/n, E-41092 Sevilla, Spain.
authors.forename: Francisco V
authors.initials: FV
authors.lastname: Dénes
authors.affiliation: Departamento de Ecologia, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves, 9500 Porto Alegre, Rio Grande do Sul, 91540-000, Brazil.
authors.forename: Viviane
authors.initials: V
authors.lastname: Zulian
authors.affiliation: Instituto de Ciências Biológicas, Universidade de Passo Fundo. BR 285, Bairro São José, Passo Fundo/RS, CEP: 99052-900, Brazil.
authors.forename: Nêmora P
authors.initials: NP
authors.lastname: Prestes
authors.affiliation: Instituto de Ciências Biológicas, Universidade de Passo Fundo. BR 285, Bairro São José, Passo Fundo/RS, CEP: 99052-900, Brazil.
authors.forename: Jaime
authors.initials: J
authors.lastname: Martínez
authors.affiliation: Department of Evolutionary Ecology, Museo Nacional de Ciencias Naturales, CSIC. José Gutiérrez Abascal 2, 28006 Madrid, Spain.
authors.forename: Guillermo
authors.initials: G
authors.lastname: Blanco
authors.affiliation: Department of Conservation Biology, Estación Biológica de Doñana, CSIC. Américo Vespucio s/n, E-41092 Sevilla, Spain.
authors.forename: Fernando
authors.initials: F
authors.lastname: Hiraldo
mesh_terms: D000818:Animals; D001938:Brazil; D017753:Ecosystem; D056727:Endangered Species; D005247:Feeding Behavior / Q000502:physiology; D005843:Geography; D010311:Parrots / Q000502:physiology*; D028223:Pinus / Q000502:physiology*; D058614:Seed Dispersal; D012639:Seeds / Q000502:physiology*