Amphibian chorus of the intermittent lake
Pool and edible frog (Pelophylax), agile and common frog, common and green toad, yellow-bellied toad (Bombina variegata), tree frog, fire salamander in streams. Cerkniško jezero, Planinsko polje, Ljubljansko barje, Slovenia.
Best time: 10 Apr – 5 Jun (April to June). Where: Cerkniško jezero, Zadnji kraj (south-west corner), Planinsko polje (Planina), Ljubljansko barje ditches (Iški morost) (Slovenia). Time of day: Chorus starts at dusk, full volume 1–2 h after dark to about midnight.
- You can go on your own
- Free
- No binoculars needed
- Sound 5/5
Open it in the interactive calendarSunrise and sunset listening times for the day you pick, and the map.
When is the best time?
Peak: 10 Apr – 5 Jun. Brown frogs and toads on the first mild wet nights of March; green frogs and tree frogs mid April to early June
Active from 1 Mar to 15 Jul (March to July) in a typical year.
Time of day
Chorus starts at dusk, full volume 1–2 h after dark to about midnight; green frogs also loud in warm afternoons from 14:00.
- Night chorus: 30 min after sunset → 00:00
- Warm-afternoon green frogs: 14:00 → 18:00
What will you hear?
Wall-to-wall Pelophylax chorus with tree frog 'krak-krak' on top, toad trills, yellow-bellied toad's soft 'poop-poop' from karst puddles, Savi's warbler and bittern in the mix.
Binoculars?
No binoculars needed. Chorus at the water's edge; a torch finds tree frogs, nothing else.
Where to go
- Cerkniško jezero, Zadnji kraj (south-west corner) — Shallow flooded meadows; the densest green-frog chorus when water is high. Map
- Planinsko polje (Planina) — Neighbouring intermittent polje; flooded in spring, very quiet; corncrake here too. Map
- Ljubljansko barje ditches (Iški morost) — Tree frogs and green frogs; road noise from Ig at the edges. Map
How to go on your own, and what it costs
Zadnji kraj: the lake road from Dolenje Jezero to Gorenje Jezero passes the flooded meadows — park on the verge, walk to the water's edge. Planinsko polje: the road from Planina across the polje. Iški morost: the reserve trail. All free; the park posts water levels.
Cost: Free.
Field-recording notes
Amphibian migration nights (March) bring many cars on the Cerknica lake road — DOPPS/park volunteers run toad patrols; drive slowly. Hydrophone work is good in the shallow flooded meadows (Pelophylax calls are strong in-water). All native amphibians are protected — no handling. Karst poljes fill and drain within days, so a chorus location can be gone a week later; the park posts water levels.
Sources
Similar spectacles
Natterjack toad chorusThe loudest amphibian in Britain — a rolling, ratcheting chorus audible up to 2 km away across dunes.
Natterjack toad chorus on the Kerry dunesA loud, ratcheting 'rrrrRup, rrrrRup' chorus from dozens of males in shallow dune pools — the loudest amphibian in these islands — with the Atlantic surf behind the dunes and snipe overhead.
Tree frog choruses of Zeeuws-VlaanderenA rattling, surprisingly loud 'kè-kè-kè-kè' chorus from hundreds of tree frogs around the old fortress moats and pools — audible across the polder — with marsh frogs and nightingales behind; the ramparts of Retranchement alone hold a few hundred.
Fire-bellied toads, natterjacks and blue moor frogsFire-bellied toad's melancholy 'uh...uh' by the hundred over shallow pasture ponds, moor frog's bubbling 'waug-waug' underwater chorus, natterjack's ratcheting trill carrying 2 km across dune slacks, tree frogs at full volume, bittern and crane in the background.
Marsh frog & tree frog chorusesWall-to-wall marsh frog laughter from the Camargue ditches, ratcheting tree frogs from Brenne ponds, and natterjacks rolling across the Landes dune slacks.
Frog nights in the Danube floodplain forestTree frog volleys and fire-bellied toads' soft hooting from the oxbows (Altarme), marsh frog laughter, night herons croaking overhead, nightingale and beaver tail-slaps; Danube barges as a slow low bed.
More: all spectacles in Slovenia · frog and toad choruses · Slovenia in April · Slovenia in May · Slovenia in June