Citimon · 39 sites · February–June 2026
Automatic detection of the 12 Slovenian anuran species in every minute of the Citimon soundscape recordings. The seasonal and night-time patterns match what is known of each species' breeding biology for most of them, which is the main reason to trust the results.
Rana temporaria, R. dalmatina, R. arvalis and Bufo bufo call in February–March. Hyla arborea and the water frogs (Pelophylax) take over in April–May.
Every species with reliable data calls more at night, from about 2× for Bufo bufo and the water frogs to about 8× for Hyla arborea and Rana arvalis.
Rana temporaria accounts for 121 hours of detected calling, three times more than the next species, Bufo bufo.
Bombina bombina, Bombina variegata and Bufotes viridis cannot be reported from these data.
Calling bouts per hour of recording in each month, so months with more recording are not over-weighted. Shading is scaled within each species to show the shape of its season. Bombina variegata is left unshaded because it has only 8 bouts. A calling bout is a continuous stretch of detected calling in one recording.
| Species | Bouts per recorded hour | Night : day | Bouts | Calling hours | Sites | |||
|---|---|---|---|---|---|---|---|---|
| Feb | Mar | Apr | May | |||||
| Early breeders · February–March | ||||||||
| Rana temporaria | 12.4 | 9.3 | 0.06 | 0.06 | 3.4× | 15,752 | 121.0 | 25 |
| Rana dalmatina | 4.6 | 3.8 | 0 | 0 | 6.9× | 6,299 | 20.5 | 14 |
| Bufo bufo | 3.7 | 7.0 | 2.5 | 0.40 | 2.1× | 11,886 | 41.4 | 36 |
| Rana arvalis | 2.4 | 2.7 | 0.03 | 0.03 | 8.0× | 4,408 | 11.6 | 30 |
| Late breeders · April–May | ||||||||
| Hyla arborea | 0.15 | 0.22 | 3.4 | 5.8 | 7.8× | 2,448 | 16.8 | 38 |
| Pelophylax ridibundus | 0.03 | 0.05 | 4.8 | 6.5 | 2.7× | 2,791 | 20.2 | 20 |
| Pelophylax esculentus | 0 | 0 | 1.0 | 3.1 | 1.9× | 844 | 3.3 | 7 |
| Pelophylax lessonae | 0 | 0 | 0.27 | 1.4 | 1.6× | 310 | 0.9 | 2 |
| Does not fit expectations | ||||||||
| Pelobates fuscus | 0.73 | 0.33 | 0.25 | 0.30 | 4.2× | 747 | 1.3 | 33 |
| Bombina bombina | 0.11 | 0.19 | 0.28 | 0.77 | 0.3× | 510 | 1.2 | 33 |
| Bufotes viridis | 0.22 | 0.05 | 0.02 | 0.05 | 0.6× | 122 | 0.3 | 22 |
| Bombina variegata | 0 | 0 | 0 | 0.01 | 0.2× | 8 | 0.0 | 4 |
Only Hyla arborea and the water frogs as a genus have been checked against expert annotations of Citimon recordings. For the rest, the evidence is whether the season and night activity match the species' biology, together with how confident the detections are.
Each species has three of its most confident detections to listen to, from different sites or recording periods where possible. The number on the right is the detection confidence (0–1). Clips are the original recordings, up to 12 seconds, with the volume evened out.
Calls almost only in Feb–Mar, mostly at night. Most calling time of any species.
Feb–Mar, then stops completely: zero detections in April and May.
Peaks in March, tails off through April. Calls by day as well as at night.
Season and night activity fit, but scores are low. Overlaps in time with R. dalmatina and R. temporaria.
Almost silent until April, strongest in May, eight times more active at night. On annotated Citimon recordings about 3 in 4 detections were correct and about 9 in 10 calling bouts were found.
April–May at 20 sites, high scores. Water frogs were checked only at genus level (see note).
April–May at 7 sites. Species-level split within Pelophylax is not verified.
Two sites only. Species-level split within Pelophylax is not verified.
Night-active, but detections are spread thinly over 33 sites with low scores and peak in February.
More active by day than at night, low scores.
Only 122 detections with scores at the threshold, declining through spring.
Eight detections in total. No evidence either way.
Recording effort is uneven. March holds more than two thirds of all audio, and June only about 2 hours, so June is left out of the calendar. Compare rates per recorded hour, not raw counts.
Water frogs. At genus level, roughly half of Pelophylax detections were confirmed against expert annotations and about three quarters of calling was found. The split between P. ridibundus, P. esculentus and P. lessonae has not been checked, so treat species-level water frog results as provisional.
Presence, not abundance. Calling bouts measure calling activity at the microphone. They do not count individuals, and a loud chorus and a single caller can give one bout each.
Night is 20:00–04:59 (809 h of recording); day is 05:00–19:59 (1,348 h).