title: Effective nut dispersal by magpies (Pica pica L.) in a Mediterranean agroecosystem.
abstract: Scatter-hoarding animals such as corvids play a crucial role in the dispersal of nut-producing tree species. This interaction is well known for some corvids, but remains elusive for other species such as the magpie (Pica pica), an abundant corvid in agroecosystems and open landscapes of the Palearctic region. In addition, the establishment of the individual dispersed seeds-a prerequisite for determining seed-dispersal effectiveness-has never before been documented for the interaction between corvids and nut-producing trees. We analyzed walnut dispersal by magpies in an agroecosystem in southern Spain. We used several complementary approaches, including video recording nut removal from feeders, measuring dispersal distance using radio tracking (with radio transmitters placed inside nuts), and monitoring the fate of dispersed nuts to the time of seedling emergence. Magpies were shown to be highly active nut dispersers. The dispersal distance averaged 39.6 ± 4.5 m and ranged from 4.1 to 158.5 m. Some 90% of the removed walnuts were cached later, and most of these (98%) were buried in the soil or hidden under plant material. By the time of seedling emergence, ca. 33% of nuts remained at the caching location. Finally, 12% of the cached nuts germinated and 4% yielded an emerged seedling, facilitating the transition to the next regeneration stage. The results demonstrate for the first time that magpies can be an effective scatter-hoarding disperser of a nut-producing tree species, suggesting that this bird species may play a key role in the regeneration and expansion of broadleaf forests in Eurasia.
authors.affiliation: Departamento de Ecología, Facultad de Ciencias, Universidad de Granada, E-18071, Granada, Spain. jorge@ugr.es.
authors.forename: Jorge
authors.initials: J
authors.lastname: Castro
authors.affiliation: Departamento de Zoología, Facultad de Ciencias, Universidad de Granada, E-18071, Granada, Spain.
authors.forename: Mercedes
authors.initials: M
authors.lastname: Molina-Morales
authors.affiliation: Departamento de Ecología, Facultad de Ciencias, Universidad de Granada, E-18071, Granada, Spain.|Grupo de Investigación "Ecología y Restauración Forestal" FORECO, Departamento de Ciencias de la Vida, UD Ecología, Edificio de Ciencias, Universidad de Alcalá, 28805, Alcalá De Henares, Spain.
authors.forename: Alexandro B
authors.initials: AB
authors.lastname: Leverkus
authors.affiliation: Grupo de Investigación "Ecología y Restauración Forestal" FORECO, Departamento de Ciencias de la Vida, UD Ecología, Edificio de Ciencias, Universidad de Alcalá, 28805, Alcalá De Henares, Spain.
authors.forename: Loreto
authors.initials: L
authors.lastname: Martínez-Baroja
authors.affiliation: Grupo de Investigación "Ecología y Restauración Forestal" FORECO, Departamento de Ciencias de la Vida, UD Ecología, Edificio de Ciencias, Universidad de Alcalá, 28805, Alcalá De Henares, Spain.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Pérez-Camacho
authors.affiliation: Grupo de Investigación "Ecología y Restauración Forestal" FORECO, Departamento de Ciencias de la Vida, UD Ecología, Edificio de Ciencias, Universidad de Alcalá, 28805, Alcalá De Henares, Spain.
authors.forename: Pedro
authors.initials: P
authors.lastname: Villar-Salvador
authors.affiliation: Grupo de Investigación "Ecología y Restauración Forestal" FORECO, Departamento de Ciencias de la Vida, UD Ecología, Edificio de Ciencias, Universidad de Alcalá, 28805, Alcalá De Henares, Spain.
authors.forename: Salvador
authors.initials: S
authors.lastname: Rebollo
authors.affiliation: Grupo de Investigación "Ecología y Restauración Forestal" FORECO, Departamento de Ciencias de la Vida, UD Ecología, Edificio de Ciencias, Universidad de Alcalá, 28805, Alcalá De Henares, Spain.
authors.forename: José M
authors.initials: JM
authors.lastname: Rey-Benayas
mesh_terms: D000818:Animals; D005247:Feeding Behavior; D009754:Nuts; D010842:Pica; D012377:Rodentia; D058614:Seed Dispersal; D012639:Seeds
keywords: Corvidae; Forest regeneration; Juglans; Radio tracking; Scatter-hoarding; Seed caching; Seed dispersal effectiveness