3.4 Figures

Each modelled species gets its own chapter with results. All results are display in a graphical format.

3.4.1 Estimated bird density

The results start with a figure showing the estimated bird density an observer would encounter at an average site during the first period. The line displays the point estimate for each winter. This is the most likely value for the average bird density. The three ribbons display the uncertainty around this point estimate. They are, from small/dark to wide/light, the 30%, 60% and 90% credible intervals. These numbers in the figure are always based on the non-linear model (1.6). The caption indicates whether the model is non-linear and how strong the linear trend is.

3.4.2 Indices

An index is a change compared to a baseline. This baseline is typically the estimate for some reference year. E.g we use 2013 as a baseline and compare 2015 with 2013 or 2016 with 2013. However we cannot use the figure with 2013 as baseline to compare 2015 with 2016. For that we need a figure with either 2015 or 2016 as baseline. To facilitate any pairwise comparison among years, we display one figure for every year using that year as baseline.

3.4.3 Index raster

Currently a separate index figure for each reference year is doable since the data contains only 5 years. The number of index figures will grow over the years, making it harder to interpret them. The third plot summarises the information on a raster. The x axis holds the year we want to interpret. The y axis holds the reference year. The dots given the relative change from the baseline (y axis) to the other year (x axis). Their colour indicates the strength of the change. Stronger changes have darker dots, white dots indicate no change. Red dots indicate a decrease from the baseline, blue dots an increase. A baseline with all red (blue) dots indicates the year with the largest (smallest) numbers. The shape of the dots indicates the classification of the effect. Informative dots (significant or non-significant but stable) get solid shapes.