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canonical: https://biosonic.io/bat-school
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# Which bat is that?

Last updated: 2026-07-20.

Bat School · Free & open to everyone.

A visual guide to European bats, told through their calls. Pick your country, then compare **frequency**, the **distance between calls** and call **shape** — with a real-looking spectrogram for every species.

biosonic.io/bat-school — bookmark it; updated as the guide grows.

[Listen to sample files in BioSonic](https://bat.biosonic.se/visualizer) · [Browse the species](#every-species)

The guide can be filtered to one country: Northern Europe (all), the UK, the Netherlands, Denmark, Germany or Sweden. Choosing a country switches the species names to the local language, filters the species list to those present there, and moves rare or vagrant species into a separate "Also possible here, but rare" group.

Two orientation visuals open the page:

- **Frequency Tuner** — a needle finds the pitch and names the bat (cycling through noctule, pipistrelle, soprano pipistrelle and serotine).
- **Call Shapes** — the handful of shapes every call is built from: the FM sweep, the CF tone and the QCF hook.

## Find it by frequency — the frequency ruler

Heard a peak frequency on your detector? Find the candidates here. Each bar spans the call's range; the dot marks the peak (loudest) frequency — the most reliable single number. Sorted low → high.

The ruler plots every species between roughly 15 kHz and 120 kHz. Species with two alternating pitches (common noctule, parti-coloured bat, barbastelle) get a second dot for their second peak.

| Species | Code | Peak frequency (kHz) | Full range (kHz) |
|---|---|---|---|
| Common noctule | NYCNOC | ~19 & ~26 | 17–45 |
| Parti-coloured bat | VESMUR | ~25 | 22–55 |
| Leisler's bat | NYCLEI | ~25 | 23–50 |
| Serotine | EPTSER | ~27 | 15–65 |
| Grey long-eared bat | PLEAUS | ~28 | 18–45 |
| Northern bat | EPTNIL | ~30 | 27–60 |
| Brown long-eared bat | PLEAUR | ~30–35 | 25–60 |
| Barbastelle | BARBAR | A ~33 / B ~40 | 29–47 |
| Greater mouse-eared bat | MYOMYO | ~37 | 22–86 |
| Pond bat | MYODAS | ~38 | 24–90 |
| Nathusius' pipistrelle | PIPNAT | ~39 | 36–62 |
| Kuhl's pipistrelle | PIPKUH | ~39 | 35–60 |
| Common pipistrelle | PIPPIP | ~45 | 42–76 |
| Daubenton's bat | MYODAU | ~46 | 32–85 |
| Natterer's bat | MYONAT | ~47 (broad) | 16–120 |
| Whiskered bat | MYOMYS | ~47 | 34–102 |
| Brandt's bat | MYOBRA | ~47 | 32–103 |
| Alcathoe bat | MYOALC | ~53 | 43–120 |
| Bechstein's bat | MYOBEC | ~55 | 35–108 |
| Soprano pipistrelle | PIPPYG | ~55 | 53–86 |
| Greater horseshoe bat | RHIFER | ~82 | 69–83 |
| Lesser horseshoe bat | RHIHIP | ~110 | 105–115 |

## Find it by sound — the five sound types

Almost every call is one of these five. In each tile: height = frequency, left→right = time (0–500 ms), the gap between marks = the distance between calls, and the bright part shows where the call's energy peaks.

| Sound type | Example species | What it looks and sounds like |
|---|---|---|
| 🏑 Hockey-stick | Common pipistrelle | A steep FM drop into a flat tail. The cruising call of pipistrelles and the big nyctaloid bats. |
| 🥁 Alternating | Common noctule | Two calls that swap pitch — the noctule's "chip-chop" and the barbastelle's "double knock". |
| ⚡ Steep-FM "I-bars" | Natterer's bat | Tall, near-vertical broadband sweeps with no flat tail. The Myotis group — separate them by how low the sweep ends. |
| 💧 Whisperers | Brown long-eared bat | Very quiet, faint broadband pulses in two bands. The long-eared bats — easily missed. |
| 〰️ Flat-line (CF) | Lesser horseshoe bat | A constant-frequency "staple" far above every other bat. Horseshoe bats. |

The page also groups the species into four broader shape families:

- **Pipistrelle group** — hockey-stick: a steep FM down-sweep with a flat tail. Roughly 38–60 kHz. (Nathusius', common and soprano pipistrelle.)
- **Myotis group** — tall thin "I-bars": steep broadband FM sweeps, very short pulses (2–5 ms). (Daubenton's, Natterer's, greater mouse-eared.)
- **Nyctaloid group** — low hockey-sticks (18–35 kHz). Loud; the noctule alternates two pitches. (Noctule, serotine, northern bat.)
- **The odd ones out** — barbastelle = two alternating bands. Long-eared = faint raindrops. Horseshoe = a flat staple-shaped whistle.

## Family by family — every species

Grouped by genus. Each card shows the example spectrogram, the key numbers, and the one tell that splits it from its look-alikes.

The eight genus groups on the page are: Pipistrelles (*Pipistrellus*, hockey-stick), Noctules & Leisler's (*Nyctalus*, low hockey-stick), Serotines (*Eptesicus*, low hockey-stick), Parti-coloured bat (*Vespertilio*, low hockey-stick), Myotis (*Myotis*, I-bars), Long-eared bats (*Plecotus*, raindrops), Barbastelle (*Barbastella*, two bands) and Horseshoe bats (*Rhinolophus*, flat line / staple).

### Pipistrelles (*Pipistrellus*) — hockey-stick

| Species | Code | Scientific name | Peak (kHz) | Range (kHz) | Distance between calls (ms) | Duration (ms) | Shape | Social call |
|---|---|---|---|---|---|---|---|---|
| Common pipistrelle | PIPPIP | *Pipistrellus pipistrellus* | ~45 | 42–76 | 85–100 | 5–10 | Hockey-stick (FM-QCF) | ~18–20 kHz (Type D, diagnostic) |
| Soprano pipistrelle | PIPPYG | *Pipistrellus pygmaeus* | ~55 | 53–86 | 70–100 | 6–12 | Hockey-stick (FM-QCF) | ~20–24 kHz |
| Nathusius' pipistrelle | PIPNAT | *Pipistrellus nathusii* | ~39 | 36–62 | 100–130 | 6–11 | Hockey-stick (FM-QCF) | ~18–22 kHz (multi-part song — diagnostic) |
| Kuhl's pipistrelle | PIPKUH | *Pipistrellus kuhlii* | ~39 | 35–60 | 90–130 | 6–14 | Hockey-stick (FM-QCF) | ~14–17 kHz |

- **Common pipistrelle** — Tell it apart: peak **~45 kHz** — the classic 45-vs-55 split with the soprano. In the field: edge habitat, gardens, towns — the default urban bat. Favourite spot: around buildings. Looks like: soprano pipistrelle, Nathusius' pipistrelle.
- **Soprano pipistrelle** — Tell it apart: peak **~55 kHz**, usually near water. In the field: wetlands, lake edge, riparian; tight buzz over water. Favourite spot: over water. Looks like: common pipistrelle, Nathusius' pipistrelle.
- **Nathusius' pipistrelle** — Tell it apart: peak **~39 kHz**, slow rhythm + a long, diagnostic social song. In the field: woodland edge, wetlands; long-distance migrant. Favourite spot: in the woods. Looks like: Kuhl's pipistrelle, common pipistrelle.
- **Kuhl's pipistrelle** — Tell it apart: almost identical to Nathusius — lean on social call + geography. In the field: Mediterranean origin, expanding north; around street lights. Favourite spot: around buildings. Looks like: Nathusius' pipistrelle, common pipistrelle.

### Noctules & Leisler's (*Nyctalus*) — low hockey-stick

| Species | Code | Scientific name | Peak (kHz) | Range (kHz) | Distance between calls (ms) | Duration (ms) | Shape | Social call |
|---|---|---|---|---|---|---|---|---|
| Common noctule | NYCNOC | *Nyctalus noctula* | ~19 & ~26 | 17–45 | 250–400 | 10–50 | Alternating QCF (chip-chop) | ~14–18 kHz (mating song, audible) |
| Leisler's bat | NYCLEI | *Nyctalus leisleri* | ~25 | 23–50 | 200–350 | 9–14 | Hockey-stick (FM-QCF) | ~13–18 kHz |

- **Common noctule** — Tell it apart: **alternates** a low ~19 kHz and a higher ~26 kHz call — the "plip-plop". In the field: open sky, high & early, over lakes; loud, often audible. Favourite spot: open sky, up high. Looks like: Leisler's bat, serotine, parti-coloured bat.
- **Leisler's bat** — Tell it apart: peak **~25 kHz** — between noctule and serotine. In the field: woodland edge, high flight; like a smaller, faster noctule. Favourite spot: in the woods. Looks like: noctule, serotine, Nathusius' pipistrelle.

### Serotines (*Eptesicus*) — low hockey-stick

| Species | Code | Scientific name | Peak (kHz) | Range (kHz) | Distance between calls (ms) | Duration (ms) | Shape | Social call |
|---|---|---|---|---|---|---|---|---|
| Serotine | EPTSER | *Eptesicus serotinus* | ~27 | 15–65 | 120–250 | 8–15 | FM-QCF (stronger FM) | ~22–24 kHz |
| Northern bat | EPTNIL | *Eptesicus nilssonii* | ~30 | 27–60 | 150–300 | 10–13 | FM-QCF | ~16–18 kHz |

- **Serotine** — Tell it apart: loud body sits at **~27 kHz**; the steep FM sweeps up to ~48 kHz (single peak). In the field: woodland edge, pasture, around houses; slow, "drunken" rhythm. Favourite spot: around buildings. Looks like: Leisler's bat, northern bat, parti-coloured bat.
- **Northern bat** — Tell it apart: peak **~30 kHz** + strong QCF tail; in Scandinavia, the *Eptesicus* you hear. In the field: the dominant Scandinavian bat — town lights, mountains, far north. Favourite spot: around buildings. Looks like: serotine, Leisler's bat, Nathusius' pipistrelle.

### Parti-coloured bat (*Vespertilio*) — low hockey-stick

| Species | Code | Scientific name | Peak (kHz) | Range (kHz) | Distance between calls (ms) | Duration (ms) | Shape | Social call |
|---|---|---|---|---|---|---|---|---|
| Parti-coloured bat | VESMUR | *Vespertilio murinus* | ~25 | 22–55 | 190–230 | 10–25 | Alternating QCF | ~13–14 kHz (autumn songflight — diagnostic) |

- **Parti-coloured bat** — Tell it apart: calls ~25 kHz + the audible **autumn songflight at ~13–14 kHz**. In the field: open, high-rise urban; the autumn song-flight is unmistakable. Favourite spot: open sky, up high. Looks like: noctule, Leisler's bat, northern bat.

### Myotis (*Myotis*) — I-bars

| Species | Code | Scientific name | Peak (kHz) | Range (kHz) | Distance between calls (ms) | Duration (ms) | Shape | Social call |
|---|---|---|---|---|---|---|---|---|
| Daubenton's bat | MYODAU | *Myotis daubentonii* | ~46 | 32–85 | 50–100 | 3–7 | Steep FM | rarely recorded |
| Pond bat | MYODAS | *Myotis dasycneme* | ~38 | 24–90 | 70–135 | 4–8 | FM with QCF tail | rarely recorded |
| Natterer's bat | MYONAT | *Myotis nattereri* | ~47 (broad) | 16–120 | 50–100 | 2–5 | Very broadband steep FM | rarely recorded |
| Whiskered bat | MYOMYS | *Myotis mystacinus* | ~47 | 34–102 | 60–120 | 3–6 | Steep FM | rarely recorded |
| Brandt's bat | MYOBRA | *Myotis brandtii* | ~47 | 32–103 | 60–120 | 3–7 | Steep FM | rarely recorded |
| Alcathoe bat | MYOALC | *Myotis alcathoe* | ~53 | 43–120 | 66–90 | 2–4 | Steep FM (highest, shortest) | rarely recorded |
| Bechstein's bat | MYOBEC | *Myotis bechsteinii* | ~55 | 35–108 | ~tens | 2.5–5 | Very steep FM | rarely recorded |
| Greater mouse-eared bat | MYOMYO | *Myotis myotis* | ~37 | 22–86 | 90–130 | 6–10 | Steep FM (longest, lowest) | rarely recorded |

- **Daubenton's bat** — Tell it apart: **straight-line skim over water** + energy ~45–50 kHz. In the field: skims in straight lines low over open water; fast, regular. Favourite spot: over water. Looks like: pond bat, whiskered/Brandt's. Go deeper: [Telling Daubenton's from pond bat by pulse shape (Van der Sijpe, NL, PDF)](https://www.vleermuis.net/attachments/article/123/10%20Identificatie%20van%20watervleermuizen%20en%20meervleermuizen%20aan%20de%20hand%20van%20pulskrommingen_vander%20Sijpe.pdf).
- **Pond bat** — Tell it apart: lower (~38 kHz), longer call with a QCF tail; circles over big water. In the field: hunts in circles over large open water; the Netherlands is its stronghold. Favourite spot: over water. Looks like: Daubenton's bat, greater mouse-eared bat. Go deeper: [Telling pond bat from Daubenton's by pulse shape (Van der Sijpe, NL, PDF)](https://www.vleermuis.net/attachments/article/123/10%20Identificatie%20van%20watervleermuizen%20en%20meervleermuizen%20aan%20de%20hand%20van%20pulskrommingen_vander%20Sijpe.pdf).
- **Natterer's bat** — Tell it apart: no single peak — a huge sweep dropping to a very low **~16 kHz** end (its real tell). In the field: dense woodland, gleaning; a rapid "rattlesnake" descent. Favourite spot: in the woods. Looks like: Bechstein's bat, whiskered/Brandt's.
- **Whiskered bat** — Tell it apart: cannot be split from Brandt's acoustically — log as **MYOMYS/BRA**. In the field: woodland, edge, gardens; inseparable from Brandt's on sound. Favourite spot: in the woods. Looks like: Brandt's bat, Alcathoe bat.
- **Brandt's bat** — Tell it apart: cannot be split from Whiskered acoustically — log as **MYOMYS/BRA**. In the field: older woodland; inseparable from Whiskered on sound. Favourite spot: in the woods. Looks like: whiskered bat, Alcathoe bat.
- **Alcathoe bat** — Tell it apart: terminal frequency **never drops below ~43 kHz** — its one tell. In the field: dense riparian woodland; recently described, under-recorded. Favourite spot: in the woods. Looks like: whiskered/Brandt's, Natterer's bat.
- **Bechstein's bat** — Tell it apart: high-energy, very broadband; old-woodland context. In the field: mature deciduous woodland; gleaning, quiet, range-restricted. Favourite spot: in the woods. Looks like: Natterer's bat, whiskered/Brandt's.
- **Greater mouse-eared bat** — Tell it apart: longest, lowest *Myotis* — energy ~37 kHz, slow rhythm. In the field: open-ground gleaning, beetle hunting; church-attic colonies. Favourite spot: open sky, up high. Looks like: pond bat, whiskered/Brandt's.

### Long-eared bats (*Plecotus*) — raindrops

| Species | Code | Scientific name | Peak (kHz) | Range (kHz) | Distance between calls (ms) | Duration (ms) | Shape | Social call |
|---|---|---|---|---|---|---|---|---|
| Brown long-eared bat | PLEAUR | *Plecotus auritus* | ~30–35 | 25–60 | 60–110 | 2–4 | Broad FM, very quiet, 2 harmonics | ~14–20 kHz |
| Grey long-eared bat | PLEAUS | *Plecotus austriacus* | ~28 | 18–45 | 70–120 | 3–6 | Broad FM, very quiet | rarely recorded |

- **Brown long-eared bat** — Tell it apart: faint "raindrop" pulses in **two harmonics**; a real upper band on every call. In the field: woodland; whisper-quiet (~5 m range), easily missed from the ground. Favourite spot: in the woods. Looks like: grey long-eared bat, whiskered/Brandt's.
- **Grey long-eared bat** — Tell it apart: lower (~28 kHz) than brown long-eared — but rarely separable on sound alone. In the field: open habitat, gardens; rare, southern. Favourite spot: open sky, up high. Looks like: brown long-eared bat.

### Barbastelle (*Barbastella*) — two bands

| Species | Code | Scientific name | Peak (kHz) | Range (kHz) | Distance between calls (ms) | Duration (ms) | Shape | Social call |
|---|---|---|---|---|---|---|---|---|
| Barbastelle | BARBAR | *Barbastella barbastellus* | A ~33 / B ~40 | 29–47 | 60–70 | 1.7 / 2.5 | Two alternating call types | rarely recorded |

- **Barbastelle** — Tell it apart: **alternates** Type A (~33 kHz) and Type B (~40 kHz) — like knocking on a door. In the field: woodland, ancient forest; the unmistakable "double screamer". Favourite spot: in the woods. Looks like: Nathusius' pipistrelle (Type B only).

### Horseshoe bats (*Rhinolophus*) — flat line / staple

| Species | Code | Scientific name | Peak (kHz) | Range (kHz) | Distance between calls | Duration (ms) | Shape | Social call |
|---|---|---|---|---|---|---|---|---|
| Lesser horseshoe bat | RHIHIP | *Rhinolophus hipposideros* | ~110 | 105–115 | high duty | 20–40 | CF + FM tails (staple) | ~15–42 kHz (FM) |
| Greater horseshoe bat | RHIFER | *Rhinolophus ferrumequinum* | ~82 | 69–83 | high duty | 30–40 | CF + FM tails (staple) | rarely recorded |

- **Lesser horseshoe bat** — Tell it apart: a flat **CF plateau at ~110 kHz** with a short FM leg each end. Nothing else sings that high. In the field: woodland, caves, attics; a continuous whistle high above every other bat. Favourite spot: caves & old buildings. Looks like: none — frequency is unique.
- **Greater horseshoe bat** — Tell it apart: a flat **CF plateau at ~82 kHz**; the end FM leg drops to ~65–70 kHz. In the field: pasture, caves; a continuous CF whistle, lower than the lesser horseshoe. Favourite spot: caves & old buildings. Looks like: lesser horseshoe bat (frequency differs).

### Where each species occurs

C = common, P = present, R = rare, A = absent. Species marked R for your country appear under "Also possible here, but rare or vagrant"; species marked A are hidden.

| Species | UK | Sweden | Denmark | Netherlands | Germany |
|---|---|---|---|---|---|
| Common pipistrelle | C | R | P | C | C |
| Soprano pipistrelle | C | C | C | P | P |
| Nathusius' pipistrelle | P | P | C | C | C |
| Kuhl's pipistrelle | A | A | R | R | P |
| Common noctule | C | P | C | C | C |
| Leisler's bat | P | R | P | R | P |
| Serotine | P | R | C | C | C |
| Northern bat | A | C | P | A | P |
| Parti-coloured bat | R | P | P | R | P |
| Daubenton's bat | C | C | C | C | C |
| Pond bat | A | P | R | C | P |
| Natterer's bat | P | P | P | P | C |
| Whiskered bat | P | C | R | P | C |
| Brandt's bat | P | C | R | R | P |
| Alcathoe bat | R | R | A | A | R |
| Bechstein's bat | R | R | R | R | P |
| Greater mouse-eared bat | R | R | A | R | C |
| Brown long-eared bat | C | C | C | P | C |
| Grey long-eared bat | R | A | A | R | P |
| Barbastelle | R | R | R | R | P |
| Lesser horseshoe bat | P | A | A | A | R |
| Greater horseshoe bat | P | A | A | A | R |

### Local species names

| English | Swedish | Danish | Dutch | German |
|---|---|---|---|---|
| Common pipistrelle | Sydpipistrell | Pipistrelflagermus | Gewone dwergvleermuis | Zwergfledermaus |
| Soprano pipistrelle | Dvärgpipistrell | Dværgflagermus | Kleine dwergvleermuis | Mückenfledermaus |
| Nathusius' pipistrelle | Trollpipistrell | Troldflagermus | Ruige dwergvleermuis | Rauhautfledermaus |
| Kuhl's pipistrelle | Parkpipistrell | Kuhls flagermus | Kuhls dwergvleermuis | Weißrandfledermaus |
| Common noctule (UK: Noctule) | Större brunfladdermus | Brunflagermus | Rosse vleermuis | Großer Abendsegler |
| Leisler's bat | Mindre brunfladdermus | Leislers flagermus | Bosvleermuis | Kleinabendsegler |
| Serotine | Sydfladdermus | Sydflagermus | Laatvlieger | Breitflügelfledermaus |
| Northern bat | Nordfladdermus | Nordflagermus | Noordse vleermuis | Nordfledermaus |
| Parti-coloured bat | Gråskimlig fladdermus | Skimmelflagermus | Tweekleurige vleermuis | Zweifarbfledermaus |
| Daubenton's bat | Vattenfladdermus | Vandflagermus | Watervleermuis | Wasserfledermaus |
| Pond bat | Dammfladdermus | Damflagermus | Meervleermuis | Teichfledermaus |
| Natterer's bat | Fransfladdermus | Frynseflagermus | Franjestaart | Fransenfledermaus |
| Whiskered bat | Mustaschfladdermus | Skægflagermus | Gewone baardvleermuis | Kleine Bartfledermaus |
| Brandt's bat | Tajgafladdermus | Brandts flagermus | Brandts vleermuis | Große Bartfledermaus |
| Alcathoe bat | Nymffladdermus | Alcathoe-flagermus | Nimfvleermuis | Nymphenfledermaus |
| Bechstein's bat | Bechsteins fladdermus | Bechsteins flagermus | Bechsteins vleermuis | Bechsteinfledermaus |
| Greater mouse-eared bat | Större musöra | Stor museøre | Vale vleermuis | Großes Mausohr |
| Brown long-eared bat | Brunlångöra | Brun langøre | Gewone grootoorvleermuis | Braunes Langohr |
| Grey long-eared bat | Grålångöra | Grå langøre | Grijze grootoorvleermuis | Graues Langohr |
| Barbastelle | Barbastell | Bredøret flagermus | Mopsvleermuis | Mopsfledermaus |
| Lesser horseshoe bat | Liten hästskonäsa | Lille hesteskonæse | Kleine hoefijzerneus | Kleine Hufeisennase |
| Greater horseshoe bat | Stor hästskonäsa | Stor hesteskonæse | Grote hoefijzerneus | Große Hufeisennase |

### A note on the numbers

Frequencies are in kHz, shown where the call's energy peaks (the loud, flat part — not the faint top of the FM sweep). "Distance between calls" and duration are typical **search-flight** values in milliseconds; both change a lot with what the bat is doing (commuting vs hunting vs the feeding buzz). Reference values are midpoints cross-checked across the Bat Conservation Trust guidance, Russ (2021), Barataud (2015), Middleton (2014), Skiba, batmonitoring.org and national sources (SE/DK/NL/DE).

## Hear these calls on your own recordings

Upload your WAV files and BioSonic shows the spectrogram, the species and the call statistics — so you can check every ID against this guide.

[Listen to sample files in BioSonic](https://bat.biosonic.se/visualizer) · [Start free trial](https://bat.biosonic.se/signup)

## The expert's checklist — how an expert reads a tricky call

Acoustic ID alone isn't always enough — weigh these together, and always read the habitat.

1. **Read the shape.** Hockey-stick, steep "I-bar", or flat line? That alone halves your options.
2. **Read the peak frequency.** The loudest, flattest part of the call — the single most useful number. Make sure your scale is accurate; 2 kHz can flip the species.
3. **Count the peaks.** One body, or a real upper part on every call (long-eared)? An echo fades within a call; a true second part is always there.
4. **Check call duration.** Key for Myotis. Short 2–4 ms vs longer 5–10 ms calls point to different species.
5. **Note the rhythm.** Distance between calls and any alternating "chip-chop" (noctule, parti-coloured) is a strong tell — if it's one individual.
6. **Listen.** Heterodyne to hear it; slow social calls 10×. Nathusius' social call goes bird-like when slowed.
7. **Read the habitat.** Water, woodland, buildings, open ground — the surroundings shape the call and narrow the species.
8. **Cross-check look-alikes.** For known tricky pairs, apply the specific tie-breaker rather than trusting peak frequency alone.

### Call shape tells you what the bat is doing

| Type | Shape | Used for |
|---|---|---|
| **CF** | Flat horizontal line | Orientation (horseshoe bats) |
| **QCF** | Hockey-stick (hook right) | Cruising / navigation |
| **FM** | Steep vertical line | Precise targeting when hunting |

**Feeding buzz:** calls turn vertical and pack tight — like a ping-pong ball bouncing to a stop — then return to the hockey-stick once the insect is caught.

### Three classic look-alike pairs

- **Serotine vs Brown long-eared.** Long-eared shows a real top-end on **every** call (not an echo); serotine has none. Listen as the tie-breaker.
- **Pond bat vs Daubenton's.** Both Myotis. Daubenton's flies **straight lines** over water; pond bat hunts **tight circles** over big water and calls a touch lower.
- **Common vs Nathusius pipistrelle.** Nathusius is slower (~39 kHz) and its **social song** is diagnostic; common pip is faster at ~45 kHz.

## The 30-second route — quick decision tree

A fast first pass to the right family. It won't settle every Myotis — but it gets you close in seconds.

1. A flat constant-frequency whistle at ~80 or ~110 kHz? → **Horseshoe bat**. ~82 = greater, ~110 = lesser. Done.
2. Calls alternating between two clear pitches (~33 & ~40 kHz)? → **Barbastelle**. Done.
3. Peak below ~30 kHz? → **Nyctaloid**. ~19 (alternating) = noctule, ~24 = parti-coloured, ~25 = Leisler's, ~26 = serotine, ~30 = northern bat.
4. Peak 38–55 kHz with a hockey-stick tail? → **Pipistrelle**. ~39 = Nathusius/Kuhl's, ~45 = common, ~55 = soprano.
5. Short (<5 ms), steep, very broadband FM? → **Myotis**. ~46 over water = Daubenton's, huge bandwidth to ~16 kHz = Natterer's, ~50 = whiskered/Brandt's, longest+lowest = greater mouse-eared.
6. Very quiet, faint broadband "raindrops" in two bands? → **Long-eared (Plecotus)**.

(When a country is selected, the horseshoe step is only shown if horseshoe bats occur there.)

## Listen & learn more — hear real calls & go deeper

External links — these open other websites in a new tab.

| Resource | What it is | Link |
|---|---|---|
| Listen in BioSonic | The interactive spectrogram — upload your own WAVs and check every ID against this guide. | [bat.biosonic.se/visualizer](https://bat.biosonic.se/visualizer) |
| Furesø bat sound diagrams (DK) | Listen to reference calls for the common species, with sonograms — great ear-training. | [furesoe.dn.dk](https://furesoe.dn.dk/naturen-i-furesoe/flagermus/bat-sound-diagrams-sonograms/) |
| Visual determination of Myotis (SE) | Spektrogram.chiroptera.se — the visual approach to the hardest group, with annotated shapes (PDF). | [spektrogram.chiroptera.se](https://www.spektrogram.chiroptera.se/wp-content/uploads/2015/11/VisualDeterminationOfMyotis.pdf) |
| chiroptera.se — how bats sound (SE) | Swedish bat society: per-species spectrograms and field descriptions. | [spektrogram.chiroptera.se](https://www.spektrogram.chiroptera.se/hur-later-fladdermoss/) |
| Bat Conservation Trust (UK) | UK species pages, the Good Practice Guidelines and identification notes. | [bats.org.uk](https://www.bats.org.uk/about-bats/what-are-bats/uk-bats) |
| ChiroVox | Open reference call database — searchable recordings for European species. | [chirovox.org](https://www.chirovox.org) |

## Photo credits

Bat photographs via Wikimedia Commons, reused under Creative-Commons licences with attribution: Common pipistrelle — © Jeffdelonge (CC BY-SA 3.0); Soprano pipistrelle — © Magne Flåten (CC BY-SA 3.0); Nathusius' pipistrelle — © Mnolf (CC BY-SA 3.0); Kuhl's pipistrelle — © Leonardoancillotto86 (CC BY 3.0); Common noctule — © Kamran Safi (CC BY-SA 4.0); Leisler's bat — © Manuel Werner (CC BY-SA 3.0); Serotine — © Mnolf (CC BY-SA 3.0); Northern bat — © Rauno Kalda (CC BY-SA 3.0); Parti-coloured bat — © Magne Flåten (CC BY-SA 3.0); Daubenton's bat — © AlexisMartin mb (CC BY-SA 3.0); Pond bat — © Gilles San Martin (CC BY-SA 2.0); Natterer's bat — © Rauno Kalda (CC BY-SA 4.0); Whiskered bat — © Gilles San Martin (CC BY-SA 2.0); Brandt's bat — © Rauno Kalda (CC BY-SA 4.0); Alcathoe bat — © Manuel Ruedi (CC BY-SA 3.0); Bechstein's bat — © AlexisMartin mb (CC BY-SA 3.0); Greater mouse-eared bat — © AlexisMartin mb (CC BY-SA 3.0); Brown long-eared bat — © Fourrure (CC BY-SA 2.0); Grey long-eared bat — © Jokot021 (CC BY-SA 4.0); Barbastelle — © Klaus Krahn (CC BY-SA 4.0); Lesser horseshoe bat — © Petr Vodička (CC BY-SA 4.0); Greater horseshoe bat — © Charles J. Sharp (CC BY-SA 4.0).

## Sources

- Reference frequency, distance-between-calls and duration values are midpoints cross-checked across the Bat Conservation Trust guidance, Russ (2021), Barataud (2015), Middleton (2014), Skiba, batmonitoring.org and national sources (SE/DK/NL/DE). Data on this page was research-checked in June 2026.
- Species presence per country (common / present / rare / absent) follows national sources for the UK, Sweden, Denmark, the Netherlands and Germany.
- Van der Sijpe — Identification of Daubenton's bat and pond bat from pulse curvature (NL, PDF), [vleermuis.net](https://www.vleermuis.net/attachments/article/123/10%20Identificatie%20van%20watervleermuizen%20en%20meervleermuizen%20aan%20de%20hand%20van%20pulskrommingen_vander%20Sijpe.pdf)
- Bat Conservation Trust — [UK bats](https://www.bats.org.uk/about-bats/what-are-bats/uk-bats)
- Bat photographs: Wikimedia Commons, Creative-Commons licensed, attributed above.

Last verified: 2026-07-20.

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