Frog nights in the Danube floodplain forest

Fire-bellied toad (Bombina bombina), tree frog, marsh and pool frogs, agile frog, green toad, Danube crested newt; beaver, night heron, kingfisher. Nationalpark Donau-Auen (Vienna – Hainburg), Austria.

Best time: 15 Apr – 31 May (April to May). Where: Nationalpark-Zentrum schlossORTH and the Schlossinsel, Orth an der Donau, Stopfenreuther Au (Hainburg), Lobau (Vienna, Nationalpark-Haus wien-lobAU) (Austria). Time of day: Chorus from 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: 15 Apr – 31 May. Mid April to end of May

Active from 15 Mar to 30 Jun (March to June) in a typical year.

Time of day

Chorus from dusk, full volume 1–2 h after dark to about midnight; the airport approach is quiet 23:30–05:30, so the last hour before midnight is the cleanest.

• Night chorus: 30 min after sunset → 00:00

What will you hear?

Tree 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.

Binoculars?

No binoculars needed. Chorus from the oxbow spurs after dark; a torch for tree frogs, nothing else.

Where to go

• Nationalpark-Zentrum schlossORTH and the Schlossinsel, Orth an der Donau — Underwater observation station, floodplain trails; night tours ('Pssst') run by the park. Map
• Stopfenreuther Au (Hainburg) — Where the park was born (1984 occupation); oxbows with Bombina and Hyla; dyke path. Map
• Lobau (Vienna, Nationalpark-Haus wien-lobAU) — Vienna's part of the park; ponds with tree frogs; urban hum from the Donaustadt. Map

How to go on your own, and what it costs

Orth an der Donau: park at the schlossORTH centre and walk the marked floodplain trails and dyke at night (allowed; off-trail is not). Stopfenreuth: the dyke path from the village. Lobau: Nationalpark-Haus wien-lobAU (bus from Vienna) and the pond trails. Park night tours ('Pssst') are optional.

Cost: Free; park night and boat tours (check current prices).

Who runs access

• Nationalpark Donau-Auen – night and boat tours (park authority) — Evening 'Pssst' night walks and inflatable-boat tours from Orth.

Field-recording notes

Trails and dykes are open at night; leaving them is not (national park law), and the oxbows are reached by a few marked spurs. Book the park's evening boat/inflatable tours for closer water access. Noise: Danube shipping 24 h (barges are slow and actually sit well under a frog chorus), the Vienna airport approach over the Lobau and Orth (planes until 23:30 and from 05:30), the S1 motorway near Schwechat. Hainburg end is quietest. All amphibians strictly protected; fire-bellied toads are quiet callers — omnis at water level within 3 m.

Sources

• Nationalpark Donau-Auen
• Nationalpark Donau-Auen – Orth an der Donau routes
• Nationalpark Donau-Auen – all offers (night and beaver tours)

Similar spectacles

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More: all spectacles in Austria · frog and toad choruses · Austria in April · Austria in May