Research findings

  Project Update: February 2010

Developments

The first project meeting was held in Spain in March 2009 and the second in Aberdeen in September 2009. Two postdocs, were appointed by the University of Aberdeen in September 2009 and one postdoc and a research assistant by IREC and the University de Valladolid in June 2009.

Activities

To increase the quality of existing rodent time series, seasonal vole monitoring has been implemented. Historical databases on the frequency and spatial dynamics of
vole outbreaks during the last 4 decades in NW Spain have been assembled.
GIS and remote-sensing methodologies for the analysis of climate and land use change correlates have also been selected and developed. A project website has been constructed which will contribute to knowledge dissemination between partners and a wider audience. Stakeholder analysis exercises were developed and distributed to all project partners and selection of stakeholders for the National Consultative Fora is now at
an advanced stage in each country. A stakeholder analysis workshop was held in Aberdeen which included external stakeholder participants. Specific management and policy relevant issues to be addressed in the National Fora have been identified by each partner.

Results from data analysis and population modelling.

A core database of vole time series has now been assembled between all partners. Analyses of these series have been carried out to characterise changes in vole population dynamics over time. A population model for the Montagu's harrier has been developed to predict the response of a predator to changes in climate and in prey abundance. Numerical modelling of the effects of resource dynamics on arctic fox has provided an explanation for its extinction from vast tracts of Northern Fennoscandia. The overabundance of semi-domestic reindeer provides a stable resource subsidy to the system in the form of carrion which increases the likelihood of arctic foxes being outcompeted by red foxes than if resource dynamics dominated by cyclic rodent populations. These results have allowed specific management recommendations to be made to the arctic fox conservation programs. A comprehensive demographic analysis on tawny owls demographic traits in relation to vole dynamics has been carried out that will be used as a template for other predators. The team is currently starting prospective modelling on tawny owl dynamics under different scenarios of change in vole dynamics.

Future activities

To further characterise changes in rodent dynamics, vole sampling in the field will be continued by all partners. To investigate the impacts of rodents on plant communities, further exclosure experiments will be started as are already ongoing two study sites.
The analysis of temporal changes in vole population dynamics is being expanded by developing the model to accommodate new sources of data from across Europe as they are collated. Upon
completion of the extraction of remote-sensing data, existing time series models will be expanded to relate changes in population dynamics parameters to environmental change. The new harrier population model will be used to explore sensitivity of the predator population to changes in the population dynamics of prey (cycle mean, amplitude and period length). Based on the same framework, this analysis will be expanded to other predators for which estimates of demographic parameters in relation to prey abundance have been obtained. Additional analysis of harrier dispersal and genetic analysis of vole dynamics will be carried out. To explore the effects of changing prey cycles on predatory species with contrasting life histories, models will be developed by collating demographic data from the literature and collaborating with scientists working with long-tailed skuas in high arctic Greenland where cycles of the collared lemming have collapsed. Work will also begin to develop models for studying the expected knock-on effect of changes in small rodent cycles on alternative prey species. Remote sensing and GIS datasets will be further refined to allow the parameratization of land use and productivity dynamics at different pan-European scales.
The first National consultative Fora with selected stakeholders will take place in each partner country in Spring/Early summer 2010.

Vole outbreaks in Spain reconstructed using historical information from newspapers

Vole exclosure