Fig 1.
Two examples of migration phenologies based on acoustic and citizen science data.
Acoustic counts for the years 2019–2022 (stacked color bars) and citizen science migration phenologies (black line) from the bird portal Tiira for (a) the Common sandpiper (A. hypoleucos) and (b) the Tree pipit (A. trivialis).
Fig 2.
Comparison of medians estimated from acoustic and citizen science data for spring.
Differences of medians between acoustic (light grey) and citizen science (dark grey) data are indicated as number of days (Δd). Negative differences mean the citizen science median is later than the acoustic median and vice versa for positive differences. For abbreviation keys see S1 Table.
Fig 3.
Comparison of medians estimated from citizen science and acoustic data for autumn.
Differences of medians between acoustic (light grey) and citizen science (dark grey) data are indicated as number of days (Δd). Negative differences mean the citizen science median is later than the acoustic median and vice versa for positive differences. For abbreviation keys see S1 Table.
Fig 4.
Proportion of nocturnal passerine migrants during spring and autumn season.
Proportions of 48 passerine species during spring (a) and autumn (b) migration according to their population sizes and citizen science migration schedules. The most abundant species are labelled, and abbreviation keys are given on the right.
Fig 5.
Bird densities from the weather radar and number of calling bird individuals.
Bird densities from the Vihti weather radar (red) and the total daily number of calling bird individuals (green) from 1 April to 31 May 2022. Grey bars indicate data unavailability.
Table 1.
Correlation statistics for the comparison of the radar bird densities and the acoustic counts in the spring season 2022.
Fig 6.
Bird densities from the weather radar and number of calling bird individuals.
Bird densities from the Vihti weather radar (red) and the total daily number of calling bird individuals (green) from 1 August to 31 October 2022. Grey bars indicate data unavailability.
Table 2.
Correlation statistics for the comparison of the radar bird densities and the acoustic counts in the autumn season 2022.
Table 3.
Correlation statistics for the comparison of the radar bird densities and the five most abundant calling passerines in the autumn season 2022.