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Audiograms of three Eastern cottontail rabbits (Sylvilagus floridanus). A, B, and C represent thresholds of individual rabbits with mean thresholds indicated by the solid line. The previously published audiogram for Domestic rabbits, Oryctolagus cuniculus, is shown for comparison (gray line, Heffner and Masterton 1980). The cottontails have good sensitivity over a relatively wide range and a single point of best sensitivity at 4 kHz. At a sound pressure level of 60 dB, their hearing range extends from 300 Hz to 56 kHz. Although the sensitivity of O. cuniculus extends further into the low frequencies, overall sensitivity for the two species is very similar
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Cottontail rabbits represent the first wild species of the order of lagomorphs whose hearing abilities have been determined. Cottontails, Sylvilagus floridanus, evolved in the New World, but have spread worldwide. Their hearing was tested behaviorally using a conditioned-avoidance procedure. At a level of 60 dB SPL, their hearing ranged from 300 Hz...
Citations
... Regardless, the ABR provides a relatively rapid way to estimate auditory function in animals without an extensive behavioral training regimen. Heffner and colleagues have used behavioral methods to generate audiograms for an extensive array of wild and domesticated mammals (e.g., Heffner, Heffner & Masterton, 1970;Heffner & Masterton, 1980;Heffner & Heffner, 1984, 1990Heffner et al., 1994;Heffner, Koay & Heffner, 2020; for review see Heffner & Heffner, 2014). Future behavioral studies in this species may further describe the characteristics of auditory functions of armadillos. ...
The auditory brainstem response (ABR) to tone burst stimuli of thirteen frequencies ranging from 0.5 to 48 kHz was recorded in the nine-banded armadillo (Dasypus novemcinctus ), the only extant member of the placental mammal superorder Xenarthra in North America. The armadillo ABR consisted of five main peaks that were visible within the first 10 ms when stimuli were presented at high intensities. The latency of peak I of the armadillo ABR increased as stimulus intensity decreased by an average of 20 μs/dB. Estimated frequency-specific thresholds identified by the ABR were used to construct an estimate of the armadillo audiogram describing the mean thresholds of the eight animals tested. The majority of animals tested (six out of eight) exhibited clear responses to stimuli from 0.5 to 38 kHz, and two animals exhibited responses to stimuli of 48 kHz. Across all cases, the lowest thresholds were observed for frequencies from 8 to 12 kHz. Overall, we observed that the armadillo estimated audiogram bears a similar pattern as those observed using ABR in members of other mammalian clades, including marsupials and later-derived placental mammals.
... According to Heffner and Masterton (1980), the low-frequency sensitivity for Oryctolagus is 39.5 dB, which agrees with our estimate of 40.7 dB, and the high-frequency sensitivity is 20-26 dB versus predicted 10.7 dB (Figure 3; Table A4). The Eastern cottontail (Sylvilagus floridanus) exhibits low-frequency sensitivity of 67-77 dB (Heffner et al., 2020) versus predicted 57.9 dB (Table A4), and high-frequency sensitivity ~20 dB (Heffner et al., 2020) versus predicted 6.3 dB (Table A4). Thus, the discrepancies between experimental and estimated data are about 10 dB. ...
... The estimated hearing sensitivity supports lagomorphs as better adapted to high-frequency sounds, because all lagomorph species including Megalagus turgidus show lower SPLs for the high frequencies than for the low ones ( Figure 3). However, our results do not fully confirm previous observations that smaller mammals have heightened high-frequency sensitivity, which was inferred to have been mainly to take advantage of spectral cues that aid in the ability to localize the source of sound (Heffner et al., 2020;Heffner & Heffner, 2010). ...
... The lower the sound pressure is, the more increased is the sensitivity. Actual data from behavioral audiograms for Oryctolagus cuniculus (from Heffner & Masterton, 1980) and Sylvilagus floridanus (from Heffner et al., 2020) in light red (SPL 250Hz ) and light green (SPL 32kHz ), respectively. Some ecological and behavioral traits (social and burrowing behavior, and preferred landscape) marked on the chart for the particular groups: pikas (Ochotona; yellow), Megalagus (orange), rabbits (light green), and hares (Lepus; dark green). ...
The structure of the bony labyrinth is highly informative with respect to locomotor agility (semicircular canals [SCC]) and hearing sensitivity (cochlear and oval windows). Here, we reconstructed the agility and hearing sensitivity of the stem lagomorph Megalagus turgidus from the early Oligocene of the Brule Formation of Nebraska (USA). Megalagus has proportionally smaller SCCs with respect to its body mass compared with most extant leporids but within the modern range of variability, suggesting that it was less agile than most of its modern relatives. A level of agility for Megalagus within the range of modern rabbits is consistent with the evidence from postcranial elements. The hearing sensitivity for Megalagus is in the range of extant lagomorphs for both low- and high-frequency sounds. Our data show that by the early Oligocene stem lagomorphs had already attained fundamentally rabbit-like hearing sensitivity and locomotor behavior, even though Megalagus was not a particularly agile lagomorph. This is likely because Megalagus was more of a woodland dweller than an open-habitat runner. The study of sensory evolution in Lagomorpha is practically unknown, and these results provide first advances in understanding the primitive stages for the order and how the earliest members of this clade perceived their environment.
... Nevertheless, both species of hedgehogs fall into the group of mammals that do not hear frequencies below about 400 Hz (at a level of 60 dB or less), as illustrated in Fig. 9 (cf. Heffner et al., 2020). This bimodal distribution of low-frequency hearing (unlike the approximately normal distribution of high-frequency hearing, Heffner et al., 2001b) suggests that it would be instructive to consider environmental factors that might exert selective pressure on low-frequency hearing, as well as anatomical mechanisms. ...
The behavioral audiogram and sound localization performance, together with the middle and inner ear anatomy, were examined in African pygmy hedgehogs Atelerix albiventris . Their auditory sensitivity at 60 dB SPL extended from 2 kHz-46 kHz, revealing a relatively narrow hearing range of 4.6 octaves, with a best sensitivity of 21 dB at 8 kHz. Their noise-localization acuity around the midline (minimum audible angle) was 14°, matching the mean of terrestrial mammals. The African pygmy hedgehog was not able to localize low-frequency pure tones or a 3-kHz amplitude-modulated tone when forced to rely on the interaural phase-difference cue, a trait shared by at least nine other mammals. The middle ear of Atelerix has a primitive configuration including an unfused ectotympanic, a substantial pars flaccida, a synostosed malleo-tympanic articulation and a ‘microtype’ malleus. A similar malleus morphology, including a stiff articulation with the skull, is a consistent feature of other mammals that do not hear frequencies below 400 Hz. The hearing of A. albiventris is discussed relative to the broad range of hearing and sound localization abilities found in mammals.
... As we learn more about the low-frequency hearing of birds from different lineages, lifestyles, and sizes, we may see patterns that are not yet apparent. That has been the case with mammals for which we now know that low-frequency hearing is bimodally distributed, with some species hearing below 300 Hz but others not hearing below 500 Hz (Heffner et al. 2001(Heffner et al. , 2020. That pattern was not revealed until the low-frequency limits of nearly 50 different mammals had been determined. ...
Despite the excitement that followed the report of infrasound sensitivity in pigeons 40 years ago, there has been limited followup, with only eleven species of birds having auditory thresholds at frequencies below 250 Hz. With such sparse data on low-frequency hearing, there is little understanding of why some birds hear very low frequencies while others do not. To begin to expand the phylogenetic and ecological sample of low-frequency hearing in birds, we determined the behavioral audiogram of the Indian peafowl, Pavo cristatus. Peafowl are thought to use low frequencies generated by the males’ tail feathers and wing flutters during courtship displays, and their crest feathers are reported to resonate at infrasound frequencies. The peafowl were able to respond to frequencies as low as 4 Hz, and their hearing range at 60 dB SPL extended from 29 Hz to 7.065 kHz (7.9 octaves). Removing the crest feathers reduced sensitivity at their resonant frequencies by as much as 7.5 dB, indicating a modest contribution to detectability in that range. However, perforation of the tympanic membranes severely reduced sensitivity to low frequencies, indicating that sensitivity to low frequencies is mediated primarily by the ears and cannot be attributed to some other sensory modality.
Background: Protecting crops from various threats, including vermin, pests, animals and rodents, is essential for sustaining agriculture. In India, especially in regions like Rajasthan, animal attacks result in significant crop losses, up to 40%. This section underscores the importance of safeguarding crops against these threats. Methods: According to our sustainable agriculture assessment and cognition of the primary issue of the community that was conducted across multiple rural sites within the Sawai Madhupur district of Rajasthan from 2020 to 2023. This paper employs a comparative method to conduct a comprehensive review of animal-repellent systems, along with delving into interdisciplinary research in related fields to identify key factors influencing their effectiveness and proposes a novel holistic farm protection solution system. Result: The proposed system offers robust crop protection while aiding environmental conservation and preserving local wildlife in Rajasthan, India. This paper underscores the importance of adopting IoT-based technologies for sustainable agriculture. It is a valuable resource for researchers, agronomists and various agriculture stakeholders to implement these advancements. This system holds promise for enhancing crop security, minimizing resource waste and ensuring food chain stability for generations to come.
