Table 1.
Terms used in interviews and analysis of deterrence effects and economics related to goose damage and scale of problem.
Fig 1.
The median duration effects of different deterrence methods in day intervals.
Vertical lines show minimum/maximum. Dark blue bars indicate the methods included in the statistical pairwise model, as opposed to light blue bars where the sample size does not allow them to be included.
Table 2.
Pairwise tests of the duration effects of deterrence methods with indication of p-values.
Fig 2.
Relative duration effect of each of increasing densities of passive deterrence methods set relative to ‘one per 10-20 ha’ (set to 0).
Letters indicate significant differences, meaning that ‘more than one per ha’ is significantly different from all others (A against B) (p < 0.01 in all pairwise posthoc tests), and ‘one per 2-5 ha’ is significantly different from ‘one per 10-20 ha’ (C) (p = 0.046 in pairwise posthoc test).
Fig 3.
The median area effect of deterrence methods in intervals of hectares.
Vertical lines show minimum/maximum. Dark blue bars indicate the methods included in the statistical pairwise model, as opposed to light blue bars where the sample size does not allow them to be included.
Table 3.
Pairwise tests of the area effect of the deterrence methods with indication of p-values.
Fig 4.
The effectiveness of the deterrence methods used, expressed by the intersect between the median duration and area effects, divided into four quadrants.
For derogation shooting where no data is available to assess the area effect, it is assumed that the area effect corresponds to the median for scare shots. For durations that are estimated to be longer than 21 days, the value is set at 22. Likewise, for area coverages larger than 20 ha, the values are set at 21.
Table 4.
Test of the extent of the goose problem in relation to season with the highest goose problem and area in rotation.
Fig 5.
Assessed economic costs of goose handling by farmers in relation to perceived annual yield loss.
Costs for handling the goose problems are expressed in time consumption per week converted into labour costs (EURO) (A), costs of deterrence equipment and fuel for driving (B), total resource costs (labour costs + equipment + fuel costs) for one week of mitigation (C), and a scenario for 20 weeks of mitigation efforts (D). In the scenario for 20 weeks of mitigation, costs for deterrentsand fuel are kept fixed, while time expenditure increase with length of the mitigation period.
Table 5.
Hunters availability to perform derogation shooting of barnacle geese.