Näytä suppeat kuvailutiedot

dc.contributor.authorEccard, Jana
dc.contributor.authorJokinen, Ilmari
dc.contributor.authorYlönen, Hannu
dc.date.accessioned2012-08-20T08:42:25Z
dc.date.available2012-08-20T08:42:25Z
dc.date.issued2011
dc.identifier.citationEccard, J., Jokinen, I., & Ylönen, H. (2011). Loss of density-dependence and incomplete control by dominant breeders in a territorial species with density outbreaks. BMC Ecology, 11 (16).
dc.identifier.urihttps://jyx.jyu.fi/handle/123456789/38311
dc.description.abstractBackground: A territory as a prerequisite for breeding limits the maximum number of breeders in a given area, and thus lowers the proportion of breeders if population size increases. However, some territorially breeding animals can have dramatic density fluctuations and little is known about the change from density-dependent processes to density-independence of breeding during a population increase or an outbreak. We suggest that territoriality, breeding suppression and its break-down can be understood with an incomplete-control model, developed for social breeders and social suppression. Results: We studied density dependence in an arvicoline species, the bank vole, known as a territorial breeder with cyclic and non-cyclic density fluctuations and periodically high densities in different parts of its range. Our long-term data base from 38 experimental populations in large enclosures in boreal grassland confirms that breeding rates are density-regulated at moderate densities, probably by social suppression of subordinate potential breeders. We conducted an experiment, were we doubled and tripled this moderate density under otherwise the same conditions and measured space use, mortality, reproduction and faecal stress hormone levels (FGM) of adult females. We found that mortality did not differ among the densities, but the regulation of the breeding rate broke down: at double and triple densities all females were breeding, while at the low density the breeding rate was regulated as observed before. Spatial overlap among females increased with density, while a minimum territory size was maintained. Mean stress hormone levels were higher in double and triple densities than at moderate density. Conclusions: At low and moderate densities, breeding suppression by the dominant breeders, But above a density-threshold (similar to a competition point), the dominance of breeders could not be sustained (incomplete control). In our experiment, this point was reached after territories could not shrink any further, while the number of intruders continued to increase with increasing density. Probably suppression becomes too costly for the dominants, and increasing number of other breeders reduces the effectiveness of threats. In wild populations, crossing this threshold would allow for a rapid density increase or population outbreaks, enabling territorial species to escape density-dependency.fi
dc.language.isoeng
dc.publisherBioMed Central (BMC)
dc.relation.ispartofseriesBMC Ecology
dc.relation.urihttp://www.biomedcentral.com/1472-6785/11/16
dc.subject.otherdominanssifi
dc.subject.otherterritoriaalisuusfi
dc.subject.othersosiaalinen kontrollifi
dc.subject.otherdominancefi
dc.subject.otherterritorialitfi
dc.subject.othersocial controlfi
dc.titleLoss of density-dependence and incomplete control by dominant breeders in a territorial species with density outbreaks
dc.typeArticle
dc.identifier.urnURN:NBN:fi:jyu-201208202181
dc.contributor.laitosBio- ja ympäristötieteiden laitosfi
dc.contributor.laitosThe Department of Biological and Environmental Scienceen
dc.type.urihttp://purl.org/eprint/type/JournalArticle
dc.identifier.doidoi:10.1186/1472-6785-11-16
dc.type.coarjournal article
dc.description.reviewstatuspeerReviewed
dc.relation.issn1472-6785
dc.type.versionpublishedVersion
dc.rights.copyright© 2011 Eccard et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
dc.rights.accesslevelopenAccessfi
dc.rights.urlhttp://creativecommons.org/licenses/by/2.0


Aineistoon kuuluvat tiedostot

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Aineisto kuuluu seuraaviin kokoelmiin

Näytä suppeat kuvailutiedot

© 2011 Eccard et al; licensee BioMed Central Ltd. 


This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Ellei muuten mainita, aineiston lisenssi on © 2011 Eccard et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.