Harmonized methods for estimating abundance of wildlife host species in Europe

Objective:

The main objective is to identify harmonized methods for estimating abundance of key wildlife host species in Europe: wild carnivores including canids, wild boar, deer (particularly Cervinae), bovids, rodents, lagomorphs and birds (Gortazar et al. 2007). These host species are the main reservoirs of the key wildlife pathogens specified in work package 2. Aphaea will concentrate particularly on wild boar, fox and rodents.

Subobjective 1: To develop an overview of the current methods for estimating abundance of key wildlife host species in Europe by means of literature review and consultation with target groups in European wildlife disease network

Subobjective 2: To develop harmonized protocols for estimating abundance of key wildlife host species in Europe based on current overview developed under subobjective 1

The knowledge of abundance of wildlife host species is important to design appropriate sampling protocols for disease surveys, to develop disease contingency plans, to assess the risk of disease transmission to other species, and to guide wildlife management strategies in general (Acevedo et al. 2008). Because the methods for estimating population abundance are generally not harmonized across Europe, we lack a Europe-wide overview of population trends of important wildlife species and of pathogen occurrence in these species.

The objective will be reached in two steps. First, we will perform a literature review of the methods currently in use to assess the abundance of each species. We will also solicit research teams and members of the newly established European wildlife disease network (see work package 4) for information about the methods in use, including grey literature and unpublished data. This will provide an overview of the available methods for each species. Second, we will critically assess these methods for capability to produce reliable measures of population abundance and/or density, with a special focus on accuracy and precision, which correspond to the main limitations of census methods (Caughley 1977, Gaillard et al. 2003, Morellet et al. 2007). Most reliable methods currently employed, such as capture-recapture modeling or line transects, have been used in restricted areas, most often to monitor a single population, while we will look for a method to be applied at large spatial scales.

Milestones and Deliverables:

From the candidate methods, using both field and in silico testing, we will select the most appropriate to use across Europe, after adjustments if necessary. Ideally, the chosen method for each species will be simple, able to provide reliable information on trends in population size or density and based on a clearly defined sampling design allowing a measure of the uncertainty to be estimated.