Scavenging in Mediterranean ecosystems: effect of the invasive Argentine ant
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Above-ground invertebrates may represent a high proportion of animal biomass, but few data are available on their fate after death. In Mediterranean ant communities, they are frequently scavenged by ants. Here, we assessed the consequences of Argentine ant invasion on the removal of arthropod corpses in Doñana National Park (SW Spain). In three natural habitats that differed in their degree of vegetation cover (i.e. protection for ants against high temperatures), we experimentally provided dead Drosophila, and observed their disappearance over a 60-min period at different times of day and year. The habitats used were isolated cork oak trees, pine tree forest and dry scrubland; we compared invaded with uninvaded plots in each. Oak trees were the most invaded habitat, while scrubland was the least and the only one where the Argentine ant coexisted with native ant species. In accordance with this degree of invasion, the Argentine ant removed the highest percentage of dead flies in oak trees and the lowest in scrubland. Its performance as scavenger was higher than uninvaded ant communities, but it was reduced at high temperatures, when native species were highly efficient. The saturated distribution of the Argentine ant colony seems to be the key to its efficiency. We discuss how the occurrence and scavenger efficiency of the Argentine ant could affect the nutrient cycling and the progression of its invasion.
KeywordsLinepithema humile Doñana Temperature Ant communities Arthropod corpses
We are grateful to Beatriz Estrada who provided the thousands of Drosophila needed for our experiment, to Cristina Pérez and Nicolas Guirlet for their help during field experiments, to Ana Carvajal for her help in identifying the ant species, to Raphael Boulay for comments on previous drafts, to Jessica Pearce and Bill McDowell also for their comments and English language editing, to three anonymous reviewers for their suggestions to ameliorate de ms and to José Boixo, Juan Calderón, Fernando Ibáñez and Ramón Soriguer for historic information about the presence of the Argentine ant in Doñana. Authorities of Doñana National Park gave the authorization for fieldwork. Other fieldwork facilities were provided by ICTS-RBD. This work was supported by Spanish Ministry of Science and Innovation (Consolider MONTES, CSD 2008-00040 and Juan de la Cierva contract to E. A.) and Consejo Superior de Investigaciones Científicas (JAE postdoctoral contract to S. C.).
- Angulo E, Boulay R, Rodrigo A, Retana J, Cerdá X (2007) Efecto de una especie invasora, Linepithema humile, la hormiga argentina, sobre la biodiversidad del Parque Nacional de Doñana (Huelva): descripción de las interacciones con las hormigas nativas. In: Ramírez L, Asensio B (eds) Investigación en Parques Nacionales: 2003–2006. Ministerio de Medio Ambiente, Madrid, pp 161–179Google Scholar
- Bestelmeyer B, Rios Casanova L (2010) Box 3.1. Field techniques for sampling ants. In: Lach L, Parr CL, Abott KL (eds) Ant ecology. Oxford University Press, UK, pp 39–41Google Scholar
- Cerdá X (2001) Behavioural and physiological traits to thermal stress tolerance in two Spanish desert ants. Etología 9:15–27Google Scholar
- Crist TO (2009) Biodiversity, species interactions, and functional roles of ants (Hymenoptera: Formicidae) in fragmented landscapes: a review. Myrmecol news 12:3–13Google Scholar
- Cros S, Cerdá X, Retana J (1997) Spatial and temporal variations in the activity patterns of Mediterranean ant communities. Ecoscience 4:269–278Google Scholar
- Retana J, Cerdá X, Espadaler X (1991) Arthropod corpses in a temperate grassland: a limited supply? Hol Ecol 14:63–67Google Scholar
- SAS Inst. Inc. (2008) SAS OnlineDoc 9.1.3. CaryGoogle Scholar
- StatSoft Inc. (2007) STATISTICA (data analysis software system), version 8.0. http://www.statsoft.com
- von Aesch L, Cherix D (2005) Introduced ant species and mechanisms of competition on Floreana island (Galápagos, Ecuador) (Hymenoptera: Formicidae). Sociobiology 45:463–481Google Scholar