共查询到20条相似文献,搜索用时 0 毫秒
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J A Simmons W A Lavender B A Lavender C A Doroshow S W Kiefer R Livingston A C Scallet D E Crowley 《Science (New York, N.Y.)》1974,186(4169):1130-1132
Echolocating bats can use sonar to discriminate among targets which reflect echoes differing in spectral distribution of energy but not in overall intensity. They can detect differences smaller than 1 millimeter in fine target structure. Bats may be capable of classifying targets from echo spectral signatures and might thus be able to distinguish among flying insect prey by sonar. 相似文献
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As an echolocating bat closes in on a flying insect, it increases call emission to rates beyond 160 calls per second. This high call rate phase, dubbed the terminal buzz, has proven enigmatic because it is unknown how bats are able to produce calls so quickly. We found that previously unknown and highly specialized superfast muscles power rapid call rates in the terminal buzz. Additionally, we show that laryngeal motor performance, not overlap between call production and the arrival of echoes at the bat's ears, limits maximum call rate. Superfast muscles are rare in vertebrates and always associated with extraordinary motor demands on acoustic communication. We propose that the advantages of rapid auditory updates on prey movement selected for superfast laryngeal muscle in echolocating bats. 相似文献
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Optomotor responses to monocular stimulation: relation to visual system organization 总被引:1,自引:0,他引:1
Results of tests on 4 mammalian, 19 reptilian, and 17 avian species confirmed the prediction that lack of optomotor response to monocular optokinetic stimulation in one of the two horizontal directions would correlate with afoveate retinal organization, whereas consistent optomotor responses to monocular stimulation in either horizontal direction would correlate with foveate organization. 相似文献
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Bats of the family Vespertilionidae enmit strong ultrasonic pulses for echolocation. If such sounds directly stimulate their ears, the detection of echoes from short distances would be impaired. The responses of lateral lemniscal neurons to emitted sounds were found to be much smaller than those to playback sounds, even when the response of the auditory nerve was the same to both types of sounds. Thus, responses to self-vocalized sounds were attenuated between the cochlear nerve and the inferior colliculus. The mean attenuation was 25 decibels. This neural attenuating mechanism is probably a part of the mechanisms for effective echo detection. 相似文献
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Human infants were placed inside a stationary cylinder containing a columnar pattern like that used to elicit the optokinetic reflex. By sequential illumnination of the columns, the pattern was made to appear to rotate. Optokinetic nystagmus was clearly evoked in 64.7 percent of the subjects, with a weak-positive response in an additional 11.8 percent. 相似文献
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The mustache bat emits a three-harmonic echolocation pulse. At the external ear, large interaural intensity differences are generated only when a sound originates within a limited area of two-dimensional space, and this area is different for each pulse harmonic. As a consequence, the external ear generates pronounced binaural spectral cues containing two-dimensional spatial information. This information is encoded in the inferior colliculus by neurons tuned to one of the harmonics and sensitive to interaural intensity differences. 相似文献
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J I Dalland 《Science (New York, N.Y.)》1965,150(700):1185-1186
Absolute hearing thresholds for two bats were determined by an operant conditioning technique. Pure tones rangingFrom 2.5 to 100 kilocycles per second were perceived by a single Eptesicus fuscus. Its maximum sensitivity was on the order of 68 decibles below 1 dyne per square centimeter and occurred at 20 kc/ sec. Maximum sensitivity for a single Myotis lucifugus was about 64 db below 1 dyne/ cm2 and occurred at 40 kc/ sec. The Myotis clearly heard a tone of120 kc/ sec but gave no evidence of hearing below 10 kc/ sec. 相似文献
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Radio tracking of homing bats 总被引:1,自引:0,他引:1
Neotropical bats, Phyllostomas hastatus, were released 10 kilometers from their home roost, and their homeward flights were tracked by radio. Flights of bats with unimpeded vision were strongly oriented in the homeward direction, while the flights of blindfolded bats did not show this marked orientation. 相似文献
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Fenton MB Davison M Kunz TH McCracken GF Racey PA Tuttle MD 《Science (New York, N.Y.)》2006,311(5764):1098-9; author reply 1098-9
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Salazar-Bravo J Phillips CJ Bradley RD Baker RJ Yates TL Ruedas LA 《Science (New York, N.Y.)》2006,311(5764):1099-100; author reply 1099-100
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A method is described for photographing bats or other rapidly moving objects as they intercept in space a particular area which is covered by a camera system. Photographs taken at Carlsbad Caverns show that the tail membrane of the Mexican freetail bat is extended when the animal is in flight. 相似文献
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Muijres FT Johansson LC Barfield R Wolf M Spedding GR Hedenström A 《Science (New York, N.Y.)》2008,319(5867):1250-1253
Staying aloft when hovering and flying slowly is demanding. According to quasi-steady-state aerodynamic theory, slow-flying vertebrates should not be able to generate enough lift to remain aloft. Therefore, unsteady aerodynamic mechanisms to enhance lift production have been proposed. Using digital particle image velocimetry, we showed that a small nectar-feeding bat is able to increase lift by as much as 40% using attached leading-edge vortices (LEVs) during slow forward flight, resulting in a maximum lift coefficient of 4.8. The airflow passing over the LEV reattaches behind the LEV smoothly to the wing, despite the exceptionally large local angles of attack and wing camber. Our results show that the use of unsteady aerodynamic mechanisms in flapping flight is not limited to insects but is also used by larger and heavier animals. 相似文献
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Echo-ranging neurons in the inferior colliculus of bats 总被引:1,自引:0,他引:1
N Suga 《Science (New York, N.Y.)》1970,170(956):449-452
Bats measure the distance to an object in terms of the time lag between their outgoing orientation sounds and the returning echo. For measurement of the time lag, the latency of response of a neuron to a stimulus must be nearly constant regardless of the stimulus amplitude and envelope. Otherwise, a large error would be introduced into the measurement. Bats have neurons that are specialized for echo ranging. 相似文献
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Simmons NB 《Science (New York, N.Y.)》2005,307(5709):527-528