Singing Rats and Sonar Bats

Secret Worlds ◽  
2021 ◽  
pp. 25-52
Author(s):  
Martin Stevens
Keyword(s):  
Auditory System ◽  
Ultrasonic Vocalizations ◽  
Ultrasonic Calls ◽  
Wide Range ◽  
Prey Items

This chapter examines how animals have evolved a wide range of hearing organs to detect features of sound, some responding more to changes in intensity, others more to changes in pressure. Ears have evolved numerous times independently and they can occur in a range of structures and body locations. Hearing has numerous functions. For many animals, it is vital for detecting threats, such as an approaching predator. Hearing is also critical to a variety of other activities, from communicating territory ownership and trying to attract a mate, to detecting prey items in the undergrowth, and even sometimes in navigation. Of all animals, the group that must surely have the most remarkable and sophisticated hearing is the bats. Many bat species can echolocate using sounds that they produce themselves. The chapter also looks at the auditory system of owls and how rodents produce ultrasonic calls, called ultrasonic vocalizations (USVs).

scholarly journals Sources of variation in the feeding ecology of the piked spurdog (Squalus megalops): implications for inferring predator–prey interactions from overall dietary composition

2005 ◽  
Vol 62 (6) ◽  
pp. 1076-1094 ◽  
Author(s):  
J. Matías Braccini ◽  
Bronwyn M. Gillanders ◽  
Terence I. Walker
Keyword(s):  
Spatial And Temporal Variation ◽  
Dietary Composition ◽  
Bootstrap Analysis ◽  
Predator Prey ◽  
Ecological Relationships ◽  
Wide Range ◽  
Opportunistic Predator ◽  
Sources Of Variation ◽  
Males And Females ◽  
Prey Items

Abstract Sources of variation in dietary composition were examined in the piked spurdog (Squalus megalops). The species is an opportunistic predator that consumes a wide range of prey items. When importance of prey was measured by weight or occurrence, S. megalops preyed largely on molluscs and teleosts. However, when number of prey was considered, the main items were crustaceans. A bootstrap analysis showed that considerable variability can be expected in the importance of prey items in the species' overall diet. Regional, seasonal, and ontogenetic differences in dietary composition were found, but there were no differences between mature and immature sharks or between males and females. The spatial and temporal variation in diet exhibited by S. megalops and the intrinsic natural variability of the dietary composition of this opportunistic predator suggest that studies that infer predator–prey interactions from overall diet are likely to miss information on the ecological relationships among species and thus account for only part of these interactions.

Auditory processing of complex sounds: an overview

1992 ◽  
Vol 336 (1278) ◽  
pp. 295-306 ◽  
Keyword(s):  
Auditory System ◽  
Auditory Processing ◽  
Dynamic Range ◽  
Auditory Brainstem ◽  
Frequency Selectivity ◽  
Dorsal Cochlear Nucleus ◽  
Cochlear Nerve ◽  
Complex Sounds ◽  
Wide Range ◽  
Time Coding

The past 30 years has seen a remarkable development in our understanding of how the auditory system - particularly the peripheral system - processes complex sounds. Perhaps the most significant has been our understanding of the mechanisms underlying auditory frequency selectivity and their importance for normal and impaired auditory processing. Physiologically vulnerable cochlear filtering can account for many aspects of our normal and impaired psychophysical frequency selectivity with important consequences for the perception of complex sounds. For normal hearing, remarkable mechanisms in the organ of Corti, involving enhancement of mechanical tuning (in mammals probably by feedback of electro-mechanically generated energy from the hair cells), produce exquisite tuning, reflected in the tuning properties of cochlear nerve fibres. Recent comparisons of physiological (cochlear nerve) and psychophysical frequency selectivity in the same species indicate that the ear’s overall frequency selectivity can be accounted for by this cochlear filtering, at least in band width terms. Because this cochlear filtering is physiologically vulnerable, it deteriorates in deleterious conditions of the cochlea - hypoxia, disease, drugs, noise overexposure, mechanical disturbance - and is reflected in impaired psychophysical frequency selectivity. This is a fundamental feature of sensorineural hearing loss of cochlear origin, and is of diagnostic value. This cochlear filtering, particularly as reflected in the temporal patterns of cochlear fibres to complex sounds, is remarkably robust over a wide range of stimulus levels. Furthermore, cochlear filtering properties are a prime determinant of the ‘place’ and ‘time’ coding of frequency at the cochlear nerve level, both of which appear to be involved in pitch perception. The problem of how the place and time coding of complex sounds is effected over the ear’s remarkably wide dynamic range is briefly addressed. In the auditory brainstem, particularly the dorsal cochlear nucleus, are inhibitory mechanisms responsible for enhancing the spectral and temporal contrasts in complex sounds. These mechanisms are now being dissected neuropharmacologically. At the cortical level, mechanisms are evident that are capable of abstracting biologically relevant features of complex sounds. Fundamental studies of how the auditory system encodes and processes complex sounds are vital to promising recent applications in the diagnosis and rehabilitation of the hearing impaired.

scholarly journals Rat ultrasonic vocalizations and novelty-induced social and non-social investigation behavior in a seminatural environment

2021 ◽  
Author(s):  
Indrek Heinla ◽  
Xi Chu ◽  
Anders Agmo ◽  
Eelke Snoeren
Keyword(s):  
Social Behavior ◽  
Social Interactions ◽  
Social Behaviors ◽  
Ultrasonic Vocalizations ◽  
Sensory Cues ◽  
Social Investigation ◽  
Wide Range ◽  
Vocal Signals ◽  
Transfer Of Information

Although rats are known to emit ultrasonic vocalizations (USVs), it remains unclear whether these calls serve an auditory communication purpose. For USVs to be part of communication, the vocal signals will need to be a transfer of information between two or more conspecifics, and with the possibility to induce changes in the behavior of the recipient. Therefore, the aim of our study was to investigate the role of USVs in rats' social and non-social investigation strategies when introduced into a large novel environment with unfamiliar conspecifics. We quantified a wide range of social and non-social behaviors in the seminatural environment, which could be affected by subtle signals, including USVs. We found that during the first hour in the seminatural environment the ability to vocalize did not affect how quickly rats met each other, their overall social investigation behavior, their passive social behavior nor their aggressive behavior. Furthermore, the non-social exploratory behaviors and behaviors reflecting anxiety/stress-like states were also unaffected. These results demonstrated that a disability to vocalize did not result in significant disadvantages (or changes) compared to intact conspecifics regarding social and non-social behaviors. This suggests that other (multi)sensory cues are more relevant in social interactions than USVs.

A New View of the Predation Cycle of a Planktivorous Fish, White Crappie (Pomoxis annularis)

1986 ◽  
Vol 43 (10) ◽  
pp. 1894-1899 ◽  
Author(s):  
W. John O'Brien ◽  
Barbara I. Evans ◽  
Gregory L. Howick
Keyword(s):  
Prey Item ◽  
Search Time ◽  
Handling Time ◽  
Planktivorous Fish ◽  
Present Evidence ◽  
White Crappie ◽  
Wide Range ◽  
Pomoxis Annularis ◽  
Prey Items ◽  
Predation Cycle

Predators are often categorized as either cruise or ambush feeding strategists. We present evidence that white crappie (Pomoxis annularis) are neither. Instead, the crappie swim intermittently and search only when stationary. If the crappie searched while swimming, one would expect the run speeds to be slower than the pursuit speeds, but no difference was found between these two measurements. Assuming that prey are located while swimming, a foreshortening of runs prior to pursuit would also be expected, but again, none was detectable. The duration of the search pause appears to be related to the detectability of the prey. Crappie also search during the pause immediately following the attack and ingestion of a prey item. The observation that the probabilities of detecting and pursuing a prey following a run or an attack do not differ significantly supports this conclusion. Also, the duration of the pause following a run or attack does not differ significantly over a wide range of temperatures. If these views are correct, white crappie could not forage optimally by either deleting located prey items from the diet or minimizing handling time. What they appear to be doing is creatively managing their search time.

The Nature of Preattentive Storage in the Auditory System

1995 ◽  
Vol 7 (1) ◽  
pp. 81-94 ◽  
Author(s):  
Hilary Gomes ◽  
Walter Ritter ◽  
Herbert G. Vaughan
Keyword(s):  
Auditory System ◽  
Mismatch Negativity ◽  
Event Related Potentials ◽  
Oddball Paradigm ◽  
Identical Stimulus ◽  
Standard Tone ◽  
Wide Range ◽  
Related Potentials ◽  
Stimulus Features

Event-related potentials were recorded to tones that subjects ignored while reading a book of their choosing. In all conditions, 90% of the tones were 100 msec in duration and 10% of the tones were 170 msec in duration. In a control condition, a customary oddball paradigm was used in which all of the tones were identical except for the longer duration tones. In two conditions, the tones varied over a wide range of tonal frequencies from 700 to 2050 Hz in 10 steps of 150 Hz. In another condition, the tones varied over the same frequencies but also varied in intensity from about 60 to 87 dB in steps of 3 dB. Thus, there was no “standard” tone in the sense of a frequently presented tone that had identical stimulus features. A mismatch negativity (MMN) was elicited in all conditions. The data are discussed in terms of the storage of information in the memory upon which the MMN is based.

The Diets of Sminthopsis Murina and Antechinus Stuartii (Marsupialia: Dasyuridae) in Sympatry.

1984 ◽  
Vol 11 (2) ◽  
pp. 235 ◽  
Author(s):  
BJ Fox ◽  
E Archer
Keyword(s):  
Niche Breadth ◽  
Rank Correlation ◽  
Correlation Coefficients ◽  
Pitfall Traps ◽  
Significant Component ◽  
Wide Range ◽  
Species Effect ◽  
Antechinus Stuartii ◽  
The Individual ◽  
Prey Items

In its diet, S. murina is similar to other small dasyurids that have been studied, being qualitatively opportunistic in that it feeds on a wide range of the arthropod prey available to it. Quantitatively, however, S, murina ingests significantly more Scarabaeidae, Blattodea, Coleoptera, Lepidoptera and larvae, and fewer Formicidae, Orthoptera and Isopoda than are available in pitfall traps during spring-summer, and so cannot be considered opportunistic in this sense. In autumn-winter it also takes significantly more Araneida and fewer Diptera, while Lepidoptera, Orthoptera and larvae are consumed only in the proportions in which they occur. A. stuartii consumes significantly more Coleoptera, Araneida and larvae than expected during the spring-summer season. In autumn-winter, it consumes significantly more Blattodea, Orthoptera and Arthropoda as well, but significantly fewer Formicidae and Diptera. Quantitatively, the two species differ significantly in the distribution of prey items for the spring-summer diet, and also differ in the individual diet categories of Scarabaeidae and larva during winter and for Arthropoda as well, in the total diet. The diet overlap is high (0.94) and there are significant rank correlation coefficients for diet categories, indicating no difference in the order of prey items in a qualitative sense. When the diets are analysed on the basis of habitat-season groups for each 'species' (including pitfall traps), neither habitat nor season is significant, but some of the samples are quite small. The 'species' effect is significant but largely reflects a difference between the diet items available (in pitfall traps) and those actually eaten by these two dasyurids. S. murina utilizes a wider range of prey than A. stuurtii and has a greater niche breadth; however, neither species could be called a diet specialist except in the broad sense ofinsectivores. Diet does not seem to be a significant component of the strong, microhabitat-based, ecological separation of these species.

scholarly journals Encoding of ultrasonic vocalizations in the auditory cortex

2013 ◽  
Vol 109 (7) ◽  
pp. 1912-1927 ◽  
Author(s):  
Isaac M. Carruthers ◽  
Ryan G. Natan ◽  
Maria N. Geffen
Keyword(s):  
Auditory Cortex ◽  
Auditory System ◽  
Nonlinear Model ◽  
Prediction Accuracy ◽  
Primary Auditory Cortex ◽  
Response Strength ◽  
Ultrasonic Vocalizations ◽  
Ultrasonic Frequency ◽  
Neuronal Responses ◽  
Communicative Signals

One of the central tasks of the mammalian auditory system is to represent information about acoustic communicative signals, such as vocalizations. However, the neuronal computations underlying vocalization encoding in the central auditory system are poorly understood. To learn how the rat auditory cortex encodes information about conspecific vocalizations, we presented a library of natural and temporally transformed ultrasonic vocalizations (USVs) to awake rats while recording neural activity in the primary auditory cortex (A1) with chronically implanted multielectrode probes. Many neurons reliably and selectively responded to USVs. The response strength to USVs correlated strongly with the response strength to frequency-modulated (FM) sweeps and the FM rate tuning index, suggesting that related mechanisms generate responses to USVs as to FM sweeps. The response strength further correlated with the neuron's best frequency, with the strongest responses produced by neurons whose best frequency was in the ultrasonic frequency range. For responses of each neuron to each stimulus group, we fitted a novel predictive model: a reduced generalized linear-nonlinear model (GLNM) that takes the frequency modulation and single-tone amplitude as the only two input parameters. The GLNM accurately predicted neuronal responses to previously unheard USVs, and its prediction accuracy was higher than that of an analogous spectrogram-based linear-nonlinear model. The response strength of neurons and the model prediction accuracy were higher for original, rather than temporally transformed, vocalizations. These results indicate that A1 processes original USVs differentially than transformed USVs, indicating preference for temporal statistics of the original vocalizations.

Nocturnal foraging of the Caribbean spiny lobster (Panulirus argus) on offshore reefs of Florida, USA

1997 ◽  
Vol 48 (8) ◽  
pp. 671 ◽  
Author(s):  
Carrollyn Cox ◽  
John H. Hunt ◽  
William G. Lyons ◽  
Gary E. Davis
Keyword(s):  
National Park ◽  
Reef Flat ◽  
Spiny Lobster ◽  
Panulirus Argus ◽  
Gut Contents ◽  
Wide Range ◽  
Nocturnal Foraging ◽  
The Caribbean ◽  
Biscayne National Park ◽  
Prey Items

During night dives along randomly selected transects across sand, seagrass, and rubble on the reef flat of Looe Key, a spur-and-groove coral reef, spiny lobsters (Panulirus argus) from dens on the forereef were observed foraging on the reef flat, particularly on the extensive rubble ridge and also relatively frequently in Thalassia. Subsequent sampling of the rubble revealed hundreds of taxa of appropriate prey items, many at high densities; the density of Cerithium litteratum, a favoured food item, was as high as 180 individuals m-2. Arthropods, especially spider crabs (Pitho spp.), were common in seagrass. Gut contents of 75 intermoult lobsters caught on offshore reefs at Biscayne National Park and Dry Tortugas National Park included a myriad of prey items, predominantly molluscs—especially gastropods (49%), chitons (15%), and bivalves (11%)—and arthropods (12%); many of the species in lobster guts were rubble dwellers, but some guts contained multiple prey peculiar to seagrass and sand. It is concluded that Panulirus argus can forage successfully wherever suitable prey items, especially molluscs, are abundant. However, where a wide range of substrata, including rubble, is available, rubble is preferred because of its abundant, accessible prey.

Preliminary observations on the biology of the White Shark, Carcharodon carcharias, in South Australian waters

1992 ◽  
Vol 43 (1) ◽  
pp. 1 ◽  
Author(s):  
BD Bruce
Keyword(s):  
Geographic Distribution ◽  
Deep Sea ◽  
White Shark ◽  
Sea Surface ◽  
Sea Surface Temperatures ◽  
Carcharodon Carcharias ◽  
Wide Range ◽  
Inshore Waters ◽  
The Times ◽  
Prey Items

The seasonal and geographic distribution of three size categories of white sharks, Carcharodon carcharias (<250 cm, 250-450 cm, >450 cm), is described for South Australian waters. On the basis of 217 records, C. carcharias of all sizes were widely distributed throughout the study area but were most commonly reported in inshore waters less than 15 m deep. Sea surface temperatures at the report sites ranged from 12 to 24�C. A wide range of prey items was recorded, with teleosts predominant in sharks less than 250 cm and cetaceans in sharks greater than 320 cm. The structure of the ovary of a 520 cm white shark was similar to the structures reported for other oviphagous lamnids. Sex ratios highly favoured females, suggesting some sexual segregation. Three recaptures out of 22 sharks tagged in 1990-91 have been reported, the recapture points varying from 18 to 220 km from the release points and the times at liberty ranging from 30 to 78 days.

scholarly journals Modelling firing regularity in the ventral cochlear nucleus: mechanisms, and effects of stimulus level and synaptopathy

2017 ◽  
Author(s):  
Dan F. M. Goodman ◽  
Ian M. Winter ◽  
Agnès C. Léger ◽  
Alain de Cheveigné ◽  
Christian Lorenzi
Keyword(s):  
Auditory System ◽  
Cochlear Nucleus ◽  
Time Course ◽  
Multiple Scales ◽  
Stimulus Level ◽  
Model Parameters ◽  
List Type ◽  
Ventral Cochlear Nucleus ◽  
Wide Range ◽  
Interactive Version

AbstractThe auditory system processes temporal information at multiple scales, and disruptions to this temporal processing may lead to deficits in auditory tasks such as detecting and discriminating sounds in a noisy environment. Here, a modelling approach is used to study the temporal regularity of firing by chopper cells in the ventral cochlear nucleus, in both the normal and impaired auditory system. Chopper cells, which have a strikingly regular firing response, divide into two classes, sustained and transient, based on the time course of this regularity. Several hypotheses have been proposed to explain the behaviour of chopper cells, and the difference between sustained and transient cells in particular. However, there is no conclusive evidence so far. Here, a reduced mathematical model is developed and used to compare and test a wide range of hypotheses with a limited number of parameters. Simulation results show a continuum of cell types and behaviours: chopper-like behaviour arises for a wide range of parameters, suggesting that multiple mechanisms may underlie this behaviour. The model accounts for systematic trends in regularity as a function of stimulus level that have previously only been reported anecdotally. Finally, the model is used to predict the effects of a reduction in the number of auditory nerve fibres (deafferentation due to, for example, cochlear synaptopathy). An interactive version of this paper in which all the model parameters can be changed is available online.HighlightsA low parameter model reproduces chopper cell firing regularityMultiple factors can account for sustained vs transient chopper cell responseThe model explains stimulus level dependence of firing regularityThe model predicts chopper cells fire more irregularly after deafferentationAn interactive version of the paper allows readers to change parameters

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