Brazilian free-tailed bats that were targeted by a rival’s jamming call missed their prey 77 to 85 percent of the time, according to field recordings in Arizona and New Mexico (Corcoran and Conner, Science 2014, as reported by National Geographic). That is the sharpest number in a field where sound is both a hunting tool and a weapon. The calls themselves are extreme: open-space bats in Panama emitted 122-134 dB SPL, and fishing bats exceeded 140 dB SPL (Surlykke and Kalko, PLoS ONE 2008). During the final attack, Daubenton’s bats call up to 190 times per second (Elemans et al., Science 2011), and in a flight-room test, noise that overlapped prey sounds cut a gleaning bat’s successful prey localization from 0.94 to 0.38 (Allen et al., Proceedings of the Royal Society B 2021). We aggregated data from Science, PNAS, the Journal of Experimental Biology, the Proceedings of the Royal Society B, eLife, PeerJ, PLoS ONE, the US Geological Survey and the US Fish and Wildlife Service, and readers who follow man-made sonar can compare these figures with our underwater acoustics and ocean sonar statistics.
TL;DR
- Open- and edge-space bats in Panama emitted 122-134 dB SPL; fishing bats topped 140 dB SPL (Surlykke and Kalko, PLoS ONE 2008).
- Maximum bat call intensities are generally 30 dB or more above early estimates (Jakobsen, Brinklov and Surlykke, Frontiers in Physiology 2013).
- Daubenton’s bats reach up to 190 calls per second in the feeding buzz (Elemans et al., Science 2011).
- Bats’ full vocal range spans 1 to 120 kHz, or 7 octaves (Hakansson et al., PLoS Biology 2022).
- Jammed free-tailed bats missed prey 77-85% of the time; sinFM playback cut capture from around 70% to below 20% (Corcoran and Conner, Science 2014).
- 100% (14 of 14) of free-tailed bat call sequences shifted upward when playback sat below the bat’s own frequency (Gillam et al., Proceedings of the Royal Society B 2007).
- Paired big brown bats fell silent up to 76% of the time when closer than 1 m, versus 0.08% when flying alone (Chiu et al., PNAS 2008).
- In simulated groups of 8 bats, frequency adjustment cut possible misdetections from 1.37 to 0.12 (Hase et al., Proceedings of the Royal Society B 2026).
- Anti-bat ultrasound occurs in 52 of 252 moth genera tested (21%) (Barber et al., PNAS 2022).
- Noise cut a pallid bat’s prey-localization success from 0.94 to 0.38 and raised search time from 4.08 s to 15.62 s (Allen et al., Proceedings of the Royal Society B 2021).
- Raising turbine cut-in speed to 5.0 m/s reduced bat fatalities by an average of 62% (Whitby et al., Ecological Solutions and Evidence 2024).
1. Call Frequencies and Source Levels: How Loud a Bat Really Is
Bat sonar is loud. Donald Griffin’s 1958 measurements put open-space aerial hunters at around 110 dB SPL, measured 10 cm from the mouth (this distance-standardized loudness is called the source level). Modern microphone arrays rewrote that number: the two Noctilio species that hunt over water averaged about 137 dB SPL, with maxima above 140 dB SPL (Surlykke and Kalko, PLoS ONE 2008). A 2013 review drew the general conclusion that maximum emitted intensities are 30 dB or more above the first estimates, and since decibels are logarithmic, 30 dB is a thousandfold difference in acoustic power (Jakobsen, Brinklov and Surlykke, Frontiers in Physiology 2013, which also cites the Griffin figure).
The more interesting finding is what loudness buys. Across the 11 species measured in Panama, emitted intensity varied more than tenfold, yet estimated prey detection distances varied only up to twofold, because high-frequency calls lose energy in air faster and the loudest bats were also the ones using high frequencies. Bats also turn the volume down on approach, by 4-7 dB per halving of distance to the background (Surlykke and Kalko, PLoS ONE 2008). Loudness, in other words, is spent to equalize range, not to win it. For a sense of how these ultrasonic levels compare with workplace exposure limits for people, see our industrial ultrasonic noise exposure statistics.
| Metric | Value | Source |
|---|---|---|
| Source level of open- and edge-space foragers, 11 species from 5 families, Panama | 122-134 dB SPL (at 10 cm) | Surlykke and Kalko, PLoS ONE 2008 |
| Source level of the two water-hunting Noctilio species | about 137 dB SPL average, maxima above 140 dB SPL | Surlykke and Kalko, PLoS ONE 2008 |
| Variation in emitted intensity vs variation in prey detection distance, same 11 species | more than tenfold vs up to twofold | Surlykke and Kalko, PLoS ONE 2008 |
| Maximum emitted intensities vs initial estimates | generally 30 dB or more higher | Jakobsen, Brinklov and Surlykke, Frontiers in Physiology 2013 |
| Daubenton’s bat (Myotis daubentonii) source level, laboratory vs field | 111 dB vs 119 dB | Jakobsen, Brinklov and Surlykke, Frontiers in Physiology 2013 |
| Full vocal range of Daubenton’s bat, echolocation plus social calls | 1 to 120 kHz (7 octaves) | Hakansson et al., PLoS Biology 2022 |
| Echolocating bat species with measured beam directionality | 17 of more than 1,000 species | Jakobsen, Brinklov and Surlykke, Frontiers in Physiology 2013 |
Context: the vocal membranes of Daubenton’s bat produce 10 to 95 kHz echolocation and social calls, while separate ventricular folds vibrate at 1 to 5 kHz for aggressive social calls (Hakansson et al., PLoS Biology 2022). A wider review puts typical bat calls at 100 to 120 dB re 20 micropascals at 10 cm (Moss, Ortiz and Wahlberg, Journal of Experimental Biology 2023). Most recent available data for field source levels: Surlykke and Kalko, 2008.
2. The Feeding Buzz: Up to 190 Calls per Second
The feeding buzz (also called the terminal buzz) is the final burst of calls a bat fires in the last fraction of a second before grabbing an insect. It is a bottleneck, not a flourish: Daubenton’s bats call up to 190 times per second, and the laryngeal muscles that drive those calls cannot contract faster than about 190 times per second (Elemans et al., Science 2011, University of Southern Denmark release). Echo overlap would only become the limit near 400 calls per second, so muscle speed, not hearing, sets the ceiling.
Newer work shows the buzz is a negotiated response to what the prey and the soundscape are doing. In Pratt’s roundleaf bat (Hipposideros pratti), terminal buzzes appeared in 0% of attacks on motionless mealworms but in 47% of attacks on flying moths, and masking noise alone pushed buzz occurrence on mealworms from 0% in silence to 43% at 40 dB SPL (Ma et al., BMC Biology 2025). The buzz is the bat’s way of buying more updates per second when the target or the channel gets harder.
| Metric | Value | Source |
|---|---|---|
| Maximum call rate in the feeding buzz, Daubenton’s bat | up to 190 calls per second | Elemans et al., Science 2011 |
| Call rate at which echoes would start overlapping calls | about 400 calls per second | Elemans et al., Science 2011 |
| Speed of the superfast laryngeal muscles compared with normal body muscles, and compared with the fastest human muscles | about 100 times faster; up to 20 times faster | Elemans et al., Science 2011 |
| Typical buzz repetition rate and call duration across bats | 150 to 200 Hz; 0.5 to 1 ms per call | Moss, Ortiz and Wahlberg, Journal of Experimental Biology 2023 |
| Big brown bat search calls vs approach calls | 15-20 ms at 5-10 Hz vs 2-5 ms at 20-80 Hz | Moss, Ortiz and Wahlberg, Journal of Experimental Biology 2023 |
| Terminal buzz occurrence, Hipposideros pratti, mealworm vs flying moth | 0% vs 47% of attacks | Ma et al., BMC Biology 2025 |
| Terminal buzz occurrence on mealworms, silence vs 40 dB SPL masking noise | 0% vs 43% of attacks | Ma et al., BMC Biology 2025 |
| Maximum call rate reported for bumblebee bats (Craseonycteris thonglongyai) | up to 220 calls per second | Ma et al., BMC Biology 2025 |
Outlier note: Hipposideros pratti tops out slightly above 100 calls per second, versus more than 160 in Daubenton’s bat and the big brown bat (Eptesicus fuscus), which shows that “ultrahigh” is a species trait rather than a universal number (Ma et al., BMC Biology 2025). The whole sequence from detection to interception typically takes under 1 second (Moss, Ortiz and Wahlberg, Journal of Experimental Biology 2023). Most recent available data for the muscle limit: Elemans et al., 2011.
3. Jamming Avoidance in Groups: Shift, Go Silent, or Shout
The jamming avoidance response, or JAR, is the idea that a bat moves its call frequency away from a neighbour’s so the two signals overlap less, much like radios hopping channels. Laboratory playbacks support it in some species. Japanese pipistrelles raised their terminal frequency (the lowest frequency at the end of each downward sweep) by an average of 2.1-4.5 kHz, but only when the jamming sound sat below their own calls (Takahashi et al., Journal of Experimental Biology 2014). Big brown bats showed a JAR only when the jamming frequency was within 2-3 kHz of their own baseline (Bates et al., Journal of Experimental Biology 2008).
The field data complicate the picture, and that is the real story of this section. On-board microphones on 8 wild greater mouse-tailed bats (Rhinopoma microphyllum) recorded 853 encounters with conspecifics: all bats shifted upward, regardless of the other bat’s frequency, with no correlation between the shift and the frequency gap (R = -0.08, p = 0.77) (Cvikel et al., Proceedings of the Royal Society B 2015). A sensorimotor model of Kuhl’s pipistrelle (Pipistrellus kuhlii) found that a spectral JAR lowered search-phase jamming probability by at most 4.5% and produced no significant gain in hunting performance (Mazar and Yovel, eLife 2020). The newest work offers a middle ground: in Miniopterus fuliginosus, a simple self-organized rule widened individual frequency differences and helped mainly in groups of fewer than about 10 bats (Hase et al., Proceedings of the Royal Society B 2026).
| Metric | Value | Source |
|---|---|---|
| Terminal frequency rise, Pipistrellus abramus, jamming below own call | average 2.1-4.5 kHz | Takahashi et al., Journal of Experimental Biology 2014 |
| Jamming frequency window that triggered a JAR in big brown bats (Eptesicus fuscus) | within 2-3 kHz of baseline | Bates et al., Journal of Experimental Biology 2008 |
| Individual differences in terminal frequency, 4 Miniopterus fuliginosus, single flight vs group flight | 0.6 kHz vs 1.3 kHz | Hase et al., Proceedings of the Royal Society B 2026 |
| Simulated possible misdetections, group of 8 bats, without vs with frequency adjustment | 1.37 vs 0.12 | Hase et al., Proceedings of the Royal Society B 2026 |
| Simulated possible misdetections, group of 32 bats, without vs with frequency adjustment | 15.77 vs 10.01 | Hase et al., Proceedings of the Royal Society B 2026 |
| Time paired big brown bats spent silent (pauses over 0.2 s) when closer than 1 m vs flying alone | up to 76% (mean 40% across 7 pairs) vs 0.08% | Chiu et al., PNAS 2008 |
| Increase in call intensity and duration, Pipistrellus kuhlii, under playback jamming, search phase | 5.4 dB louder; 26% longer | Amichai et al., Proceedings of the Royal Society B 2015 |
| Maximum reduction in search-phase jamming probability from a spectral JAR, model | 4.5% | Mazar and Yovel, eLife 2020 |
Context: in common pipistrelles (Pipistrellus pipistrellus), bats reacted to conspecifics at distances of 1-11 m, and the frequency gap between two bats widened in only 26.7% of shared flights, which the authors attribute to an attention response rather than jamming avoidance (Gotze et al., Scientific Reports 2016). Kuhl’s pipistrelles under heavy jamming shifted upward by 550 Hz on average, in 51 of 60 conditions, which did not reduce spectral overlap (Amichai et al., Proceedings of the Royal Society B 2015). Amichai et al. 2015 suggests calling louder and longer is the more dependable fix.
4. Mexican Free-Tailed Bats: Jamming and Being Jammed
The Brazilian free-tailed bat, known in the United States as the Mexican free-tailed bat (Tadarida brasiliensis), is the species in which bats were documented jamming a competitor’s sonar during a hunt. Its jamming signal, the sinFM (a sinusoidal frequency-modulated call), raises and lowers its pitch more than a dozen times in a single burst, sweeping across the frequencies a rival relies on. When a bat fired a sinFM at a rival closing on prey, the rival missed 77 to 85 percent of the time (Corcoran and Conner, Science 2014, as reported by National Geographic).
The same species is also among the best-documented frequency shifters. In playback trials, its search calls shifted upward within less than 200 ms of a stimulus switch, often in the very first call (Gillam et al., Proceedings of the Royal Society B 2007). A species that both jams and dodges jamming suggests the airspace above a big colony is a contested channel, not a quiet hunting ground.
| Metric | Value | Source |
|---|---|---|
| Share of attacks a rival missed while being targeted by a sinFM | 77 to 85 percent | Corcoran and Conner, Science 2014 (reported by National Geographic) |
| Capture success on tethered moths, no playback vs sinFM playback | around 70 percent vs below 20 percent | Corcoran and Conner, Science 2014 (reported by National Geographic) |
| Pitch cycles in one sinFM burst; burst length | more than a dozen; about a tenth of a second | Corcoran and Conner, Science 2014 (reported by National Geographic) |
| Roost-mates a foraging free-tailed bat may compete with | as many as one million | Wake Forest University media advisory 2014 |
| Call sequences shifting upward when playback was below the bat’s own frequency | 100% (14 of 14) | Gillam et al., Proceedings of the Royal Society B 2007 |
| Call sequences shifting upward when playback was above the bat’s own frequency | 72% (18 of 25) | Gillam et al., Proceedings of the Royal Society B 2007 |
| Latency of the frequency shift after a stimulus switch | less than 200 ms (mean inter-call interval 227 ms) | Gillam et al., Proceedings of the Royal Society B 2007 |
Caveat: the Science paper itself is paywalled; the 2014 jamming figures above come from National Geographic’s report on it, and the Wake Forest University media advisory confirms that bats “almost always missed their prey” when jammed. Most recent available data: Corcoran and Conner, 2014; Gillam et al., 2007.
5. Moth Countermeasures: Ultrasonic Clicks That Jam Sonar
Bats are not the only jammers. A survey across four tropical field sites found anti-bat ultrasound in 52 of 252 moth genera (21%), with at least six independent origins of sonar jamming (Barber et al., PNAS 2022). The authors extrapolate that perhaps 20% of the estimated 100,000 species of larger moths (Macroheterocera) produce such sounds, which turns a curiosity into a mainstream defence (Barber et al., PNAS 2022).
The mechanism is now measurable. Duty cycle (the share of time the moth’s sound is switched on) is the lever: in playback tests with the tiger moth Bertholdia trigona, big brown bats captured 77% of silent control moths, and the odds of capture fell about 4% for every 1% rise in duty cycle across a 0-46% range. The bats fought back by lengthening their buzz, gaining about 8% capture success per extra 100 ms (Fernandez, Dowdy and Conner, Journal of Experimental Biology 2022). The arms race is measured in milliseconds on both sides.
| Metric | Value | Source |
|---|---|---|
| Moth genera producing anti-bat ultrasound | 52 of 252 tested (21%) | Barber et al., PNAS 2022 |
| Independent origins of sonar jamming vs of acoustic warning signals in moths | at least six vs more than 10 | Barber et al., PNAS 2022 |
| Minimum duty cycle for moth sounds to act as jamming | at least 18% | Barber et al., PNAS 2022 |
| Bat capture success on moths in silent control trials, and change in capture odds per 1% rise in moth duty cycle | 77%; odds down about 4% | Fernandez, Dowdy and Conner, Journal of Experimental Biology 2022 |
| Bat attacks on clicking Bertholdia trigona that succeeded | around one in five | Corcoran et al., Science 2009 (reported by National Geographic) |
| Typical miss distance of bats attacking clicking moths, nights three to seven | about 15-20 cm | Corcoran et al., Journal of Experimental Biology 2011 |
| Hawkmoths answering bat echolocation playback with ultrasound, 3 Malaysian species | 48 of 51 moths | Barber and Kawahara, Biology Letters 2013 |
| Peak frequency and level of hawkmoth anti-bat sounds | 53-57 kHz; 64-68 dB peSPL | Barber and Kawahara, Biology Letters 2013 |
Context: the 15-20 cm miss distance supports the “ranging interference” explanation, in which clicks corrupt the bat’s estimate of how far away the moth is (Corcoran et al., Journal of Experimental Biology 2011). Hawkmoths make their sound by rubbing modified scales on the genitals (Barber and Kawahara, Biology Letters 2013). In the 2009 trials, most silenced tiger moths were eaten (National Geographic, 2009). Tiger beetles also answer bat calls with ultrasound, yet captive big brown bats completely consumed 90 of 94 beetles offered, so the sound may be a bluff that imitates noxious moths (Gough et al., Biology Letters 2024).
6. The Lombard Effect and Anthropogenic Noise
The Lombard effect is the automatic rise in voice level when background noise rises, the same reflex that makes people talk louder in a noisy bar. Bats have it, but it is modest. Daubenton’s bats raised their call level by only 0.18 dB for every 1 dB of added noise, going from 52.0 dB in silent controls to 64.6 dB in 102 dB broadband noise, and in noise they were almost three times more likely to need multiple attempts to complete a landing task (Uebel et al., BMC Zoology 2024). Greater horseshoe bats changed both loudness and pitch from the very first call after noise onset (Hage et al., PNAS 2013). Songbirds solve a related problem in a lower frequency band, covered in our urban songbird pitch shift statistics.
A small vocal compensation cannot cover a large cost. Gleaning bats, which find prey on the ground by listening to the sounds it makes while walking, are especially exposed: noise cut the pallid bat’s (Antrozous pallidus) prey-localization success from 0.94 in ambient conditions to 0.38 under spectrally overlapping noise, and to 0.33 under noise that did not even overlap the prey cue (Allen et al., Proceedings of the Royal Society B 2021). The non-overlapping result matters: it points to distraction, not just masking.
| Metric | Value | Source |
|---|---|---|
| Lombard slope, Daubenton’s bat landing task | 0.18 dB per dB of noise | Uebel et al., BMC Zoology 2024 |
| Call source level, silent control vs 102 dB broadband noise | 52.0 dB vs 64.6 dB | Uebel et al., BMC Zoology 2024 |
| Largest average rise in call amplitude, and largest average rise in call frequency, in band-filtered noise, greater horseshoe bat (Rhinolophus ferrumequinum) | 2.2 dB; 269 Hz | Hage et al., PNAS 2013 |
| Prey-localization success, pallid bat, ambient vs overlapping noise vs non-overlapping noise | 0.94 vs 0.38 vs 0.33 | Allen et al., Proceedings of the Royal Society B 2021 |
| Search time for prey, ambient vs overlapping noise | 4.08 s vs 15.62 s | Allen et al., Proceedings of the Royal Society B 2021 |
| Extra sonar pulses used when hunting in noise vs ambient conditions | 25% more | Allen et al., Proceedings of the Royal Society B 2021 |
| Bat passes recorded around an airport runway, Pipistrellus abramus, 11 sites | 585 passes | Wang et al., Ecology and Evolution 2022 |
| Peak frequency of airport noise vs average bat call peak frequency | 1.40-10.90 kHz vs 49.49 kHz | Wang et al., Ecology and Evolution 2022 |
Context: even with airport noise peaking far below the bats’ 49.49 kHz calls, feeding buzzes were negatively associated with aircraft activity (beta = -14.71, z = -2.96, p = .0031) (Wang et al., Ecology and Evolution 2022). The 0.18 dB/dB slope sits far below a one-for-one match, so most of the noise penalty is absorbed by the bat’s hunting rather than by its voice. Most recent available data for gleaning-bat foraging: Allen et al., 2021.
7. Wind Turbines: Ultrasonic Deterrents, Curtailment and Population Context
Wind energy is the clearest case where bat acoustics meets infrastructure. Ultrasonic deterrents try to make the airspace around a rotor acoustically unpleasant, and in cage trials they clearly change behaviour: Brazilian free-tailed bats emitted 12,611 echolocation pulses during the combined 20-50 kHz treatment versus 55,096 during control periods (Guest et al., PeerJ 2026). Our math: 12,611 / 55,096 = 22.9% of control activity. For red bats (Lasiurus blossevillii and Lasiurus borealis) the figures were 4,063 versus 19,517, or 20.8% (Guest et al., PeerJ 2026).
Behaviour in a cage is not survival at a turbine. At a 16-turbine experiment in Ohio, eastern red bat mortality was 1.9 times higher with deterrents active than in controls (95% CI 1.01 to 3.55), while curtailment alone reduced fatalities of all bats by 46% (Clerc et al., PLoS ONE 2025). Curtailment means keeping blades still at low wind speeds by raising the cut-in speed, the wind speed at which a turbine starts spinning to generate power. A decade of studies puts the gain at 33% fewer fatalities per 1.0 m/s increase (Whitby et al., Ecological Solutions and Evidence 2024). Low-frequency turbine noise affecting people is a separate issue, covered in our wind turbine infrasound statistics.
| Metric | Value | Source |
|---|---|---|
| Ultrasonic deterrent output; tone frequencies | 120 dB at 1 m; 20, 26, 32, 38, 44 and 50 kHz | Guest et al., PeerJ 2026 |
| Echolocation pulses, Brazilian free-tailed bat, control vs combined deterrent | 55,096 vs 12,611 | Guest et al., PeerJ 2026 |
| Eastern red bat mortality with deterrents vs control, Ohio | 1.9 times higher (95% CI 1.01 to 3.55) | Clerc et al., PLoS ONE 2025 |
| Eastern red bats among fresh carcasses found at experimental turbines | 86 of 154 (56%) | Clerc et al., PLoS ONE 2025 |
| Reduction in total bat fatalities per 1.0 m/s increase in curtailment wind speed | 33% | Whitby et al., Ecological Solutions and Evidence 2024 |
| Average reduction in total bat fatalities at a 5.0 m/s cut-in speed | 62% (95% CI 54% to 69%) | Whitby et al., Ecological Solutions and Evidence 2024 |
| Hoary bats (Lasiurus cinereus) vs silver-haired bats (Lasionycteris noctivagans) flying toward a white turbine blade instead of a dark empty flyway | 74% vs 97% | Jonasson et al., Biology Letters 2025 |
| Decline in tricolored bat (Perimyotis subflavus) colonies affected by white-nose syndrome | more than 90 percent | US Fish and Wildlife Service, 2022 |
Context: the deterrent response differed by species, and Guest et al. suggest focusing deterrent emissions below about 36 kHz. The Jonasson et al. Y-maze trials used 242 hoary and 154 silver-haired bats, suggesting vision, not only sound, draws bats to rotors (Jonasson et al., Biology Letters 2025). For population context, white-nose syndrome has been confirmed in 38 states and eight Canadian provinces, and bats contribute at least $3 billion annually to the US agriculture economy (US Fish and Wildlife Service, 2022). Most recent available data for the tricolored bat figures: US Fish and Wildlife Service, 2022.
Summary: Bat Echolocation, Ultrasonic Jamming and Frequency Shifting by the Numbers
| Metric | Value | Source |
|---|---|---|
| Source level of open- and edge-space foragers vs maximum of water-hunting Noctilio bats, Panama | 122-134 dB SPL vs above 140 dB SPL | Surlykke and Kalko, PLoS ONE 2008 |
| Maximum emitted intensities vs initial estimates | 30 dB or more higher | Jakobsen, Brinklov and Surlykke, Frontiers in Physiology 2013 |
| Full vocal range of Daubenton’s bat | 1 to 120 kHz (7 octaves) | Hakansson et al., PLoS Biology 2022 |
| Maximum feeding buzz call rate, Daubenton’s bat | up to 190 calls per second | Elemans et al., Science 2011 |
| Terminal buzz occurrence on mealworms, silence vs 40 dB SPL noise, Hipposideros pratti | 0% vs 43% | Ma et al., BMC Biology 2025 |
| Terminal frequency rise in Pipistrellus abramus under lower-frequency jamming | 2.1-4.5 kHz | Takahashi et al., Journal of Experimental Biology 2014 |
| Silence in paired big brown bats closer than 1 m vs alone | up to 76% vs 0.08% | Chiu et al., PNAS 2008 |
| Simulated misdetections, 8-bat group, without vs with frequency adjustment | 1.37 vs 0.12 | Hase et al., Proceedings of the Royal Society B 2026 |
| Maximum cut in search-phase jamming probability from a spectral JAR, model | 4.5% | Mazar and Yovel, eLife 2020 |
| Rival misses during sinFM jamming, Tadarida brasiliensis | 77 to 85 percent | Corcoran and Conner, Science 2014 (reported by National Geographic) |
| Capture success, no playback vs sinFM playback | around 70 percent vs below 20 percent | Corcoran and Conner, Science 2014 (reported by National Geographic) |
| Free-tailed bat sequences shifting upward when playback was lower | 100% (14 of 14) | Gillam et al., Proceedings of the Royal Society B 2007 |
| Moth genera producing anti-bat ultrasound | 52 of 252 (21%) | Barber et al., PNAS 2022 |
| Bat capture success on moths in silent control trials, B. trigona playback study | 77% | Fernandez, Dowdy and Conner, Journal of Experimental Biology 2022 |
| Lombard slope, Daubenton’s bat | 0.18 dB per dB of noise | Uebel et al., BMC Zoology 2024 |
| Prey-localization success, pallid bat, ambient vs overlapping noise | 0.94 vs 0.38 | Allen et al., Proceedings of the Royal Society B 2021 |
| Eastern red bat mortality with ultrasonic deterrents vs control | 1.9 times higher | Clerc et al., PLoS ONE 2025 |
| Average fatality reduction at 5.0 m/s cut-in speed | 62% | Whitby et al., Ecological Solutions and Evidence 2024 |
Methodology and Sources
We read every figure in the primary paper (through its journal page or PubMed Central full text) or in a named report on that paper, and we used the Europe PMC database as a search engine for peer-reviewed literature. Latin binomials follow each paper. Derived percentages show the math in the text.
- Surlykke A, Kalko EKV. Echolocating bats cry out loud to detect their prey. PLoS ONE 2008
- Jakobsen L, Brinklov S, Surlykke A. Intensity and directionality of bat echolocation signals. Frontiers in Physiology 2013
- Moss CF, Ortiz ST, Wahlberg M. Adaptive echolocation behavior of bats and toothed whales in dynamic soundscapes. Journal of Experimental Biology 2023
- Hakansson J et al. Bats expand their vocal range by recruiting different laryngeal structures. PLoS Biology 2022
- Elemans CPH et al. Superfast muscles set maximum call rate in echolocating bats. Science 2011, via the University of Southern Denmark release
- Ma N et al. Prey evasiveness and masking noise jointly promote the ultrahigh call rate in echolocating bats. BMC Biology 2025
- Takahashi E et al. Adaptive changes in echolocation sounds by Pipistrellus abramus in response to artificial jamming sounds. Journal of Experimental Biology 2014 (abstract via Europe PMC)
- Bates ME et al. Jamming avoidance response of big brown bats in target detection. Journal of Experimental Biology 2008 (abstract via Europe PMC)
- Hase K et al. Self-organized spectral adjustment in echolocation sounds within group-flying bats. Proceedings of the Royal Society B 2026
- Chiu C, Xian W, Moss CF. Flying in silence: echolocating bats cease vocalizing to avoid sonar jamming. PNAS 2008
- Cvikel N et al. On-board recordings reveal no jamming avoidance in wild bats. Proceedings of the Royal Society B 2015
- Amichai E, Blumrosen G, Yovel Y. Calling louder and longer. Proceedings of the Royal Society B 2015
- Gotze S et al. No evidence for spectral jamming avoidance in echolocation behavior of foraging pipistrelle bats. Scientific Reports 2016
- Mazar O, Yovel Y. A sensorimotor model shows why a spectral jamming avoidance response does not help bats deal with jamming. eLife 2020
- Gillam EH et al. Rapid jamming avoidance in biosonar. Proceedings of the Royal Society B 2007
- Corcoran AJ, Conner WE. Bats jamming bats: food competition through sonar interference. Science 2014, as reported by National Geographic and the Wake Forest University media advisory
- Barber JR et al. Anti-bat ultrasound production in moths is globally and phylogenetically widespread. PNAS 2022
- Fernandez Y, Dowdy NJ, Conner WE. High duty cycle moth sounds jam bat echolocation. Journal of Experimental Biology 2022
- Corcoran AJ et al. Tiger moth jams bat sonar. Science 2009, as reported by National Geographic; Corcoran AJ et al. How do tiger moths jam bat sonar? Journal of Experimental Biology 2011 (abstract via Europe PMC)
- Barber JR, Kawahara AY. Hawkmoths produce anti-bat ultrasound. Biology Letters 2013
- Gough HM et al. Tiger beetles produce anti-bat ultrasound and are probable Batesian moth mimics. Biology Letters 2024 (abstract via Europe PMC)
- Uebel AS et al. Daubenton’s bats maintain stereotypical echolocation behaviour and a Lombard response during target interception in light. BMC Zoology 2024
- Hage SR et al. Ambient noise induces independent shifts in call frequency and amplitude within the Lombard effect in echolocating bats. PNAS 2013
- Allen LC et al. Noise distracts foraging bats. Proceedings of the Royal Society B 2021
- Wang W et al. Airport noise disturbs foraging behavior of Japanese pipistrelle bats. Ecology and Evolution 2022
- Guest EE et al. Species-specific acoustic responses by bats to ultrasonic stimuli used for reducing bat-wind turbine interactions. PeerJ 2026
- Clerc J et al. Ultrasonic deterrents provide no additional benefit over curtailment in reducing bat fatalities at an Ohio wind energy facility. PLoS ONE 2025
- Whitby M et al. A decade of curtailment studies demonstrates a consistent and effective strategy to reduce bat fatalities at wind turbines in North America. Ecological Solutions and Evidence 2024, USGS publication page
- Jonasson KA et al. Bats flying through a Y-maze are visually attracted to wind turbine surfaces. Biology Letters 2025
- US Fish and Wildlife Service. Proposal to list the tricolored bat as endangered. Press release, September 2022
- Data watch: most behavioural studies use small samples (3 pallid bats in Allen et al. 2021, 3 big brown bats in Fernandez et al. 2022, 3 horseshoe bats in Hage et al. 2013, 5 Daubenton’s bats in Uebel et al. 2024), so effect sizes should not be read as population averages. The 2014 sinFM and 2009 tiger moth capture figures come from National Geographic’s reporting because the Science papers are paywalled; National Geographic’s 2009 piece gives an inconsistent bat count (four in one place, three in another). Surlykke and Kalko 2008 quote a 122-144 dB SPL range in one Results passage that appears nowhere else in the paper; we use the abstract’s 122-134 dB SPL and above 140 dB SPL figures. Fernandez et al. 2022 report a correlation sign for buzz duration that conflicts with their own regression; we cite only the regression. Jonasson et al. 2025 give a hoary bat preference ratio of 2.9 in the Discussion and 2.82 in Table 1, so we cite only the 74% and 97% shares. The Guest et al. 2026 percentages of control activity are our own arithmetic from the raw pulse counts. Evidence for a spectral jamming avoidance response remains split between laboratory playbacks (sections 3 and 4) and field and modelling studies that find none (section 3). The tricolored bat listing figures date from the 2022 proposal; a final rule would update them.
Last updated: October 25, 2026. We update this roundup quarterly, and the next refresh is expected when the US Fish and Wildlife Service publishes its final listing decision for the tricolored bat.