scholarly journals Mate choice in the eye and ear of the beholder? Female multimodal sensory configuration influences her preferences

2018 ◽  
Vol 285 (1878) ◽  
pp. 20180713 ◽  
Author(s):  
Kelly L. Ronald ◽  
Esteban Fernández-Juricic ◽  
Jeffrey R. Lucas

A common assumption in sexual selection studies is that receivers decode signal information similarly. However, receivers may vary in how they rank signallers if signal perception varies with an individual's sensory configuration. Furthermore, receivers may vary in their weighting of different elements of multimodal signals based on their sensory configuration. This could lead to complex levels of selection on signalling traits. We tested whether multimodal sensory configuration could affect preferences for multimodal signals. We used brown-headed cowbird ( Molothrus ater ) females to examine how auditory sensitivity and auditory filters, which influence auditory spectral and temporal resolution, affect song preferences, and how visual spatial resolution and visual temporal resolution, which influence resolution of a moving visual signal, affect visual display preferences. Our results show that multimodal sensory configuration significantly affects preferences for male displays: females with better auditory temporal resolution preferred songs that were shorter, with lower Wiener entropy, and higher frequency; and females with better visual temporal resolution preferred males with less intense visual displays. Our findings provide new insights into mate-choice decisions and receiver signal processing. Furthermore, our results challenge a long-standing assumption in animal communication which can affect how we address honest signalling, assortative mating and sensory drive.

2020 ◽  
pp. jeb.233288
Author(s):  
Ryan C. Taylor ◽  
Kyle O. Wilhite ◽  
Rosalind J. Ludovici ◽  
Kelsey M. Mitchell ◽  
Wouter Halfwerk ◽  
...  

Noise is a common problem in animal communication. We know little, however, about how animals communicate in noise using multimodal signals. Multimodal signals are hypothesized to be favoured by evolution because they increase the efficacy of detection/discrimination in noisy environments. We tested the hypothesis that female túngara frogs’ responses to attractive male advertisement calls are improved in noise when a visual signal component is added to the available choices. We tested this at two levels of decision complexity (two and three choices). In a two-choice test, the presence of noise did not reduce female preferences for attractive calls. The visual component of a calling male, associated with an unattractive call, also did not reduce preference for attractive calls in the absence of noise. In the presence of noise, however, females were more likely to choose an unattractive call coupled with the visual component. In three-choice tests, the presence of noise alone reduced female responses to attractive calls and this was not strongly affected by the presence or absence of visual components. The responses in these experiments fail to support the multimodal signal efficacy hypothesis. Instead, the data suggest that audio-visual perception and cognitive processing, related to mate choice decisions, are dependent on the complexity of the sensory scene.


1994 ◽  
Vol 6 (4) ◽  
pp. 400-411 ◽  
Author(s):  
Avishai Henik ◽  
Robert Rafal ◽  
Dell Rhodes

Nine patients with chronic, unilateral lesions of the dorso-lateral prefrontal cortex including the frontal eye fields (FEF) made saccades toward contralesional and ipsilesional fields. The saccades were either voluntarily directed in response to arrows in the center of a visual display, or were reflexively summoned by a peripheral visual signal. Saccade latencies were compared to those made by seven neurologic control patients with chronic, unilateral lesions of dorsolateral prefrontal cortex sparing the FEF, and by 13 normal control subjects. In both the normal and neurologic control subjects, reflexive saccades had shorter Latencies than voluntary saccades. In the FEF lesion patients, voluntary saccades had longer latencies toward the contralesional field than toward the ipsilesional field. The opposite pattern was found for reflexive saccades: latencies of saccades to targets in the contralesional field were shorter than saccades summoned to ipsilesional targets. Reflexive saccades toward the ipsilesional field had abnormally prolonged latencies; they were comparable to the latencies observed for voluntary Saccades. The effect of FEF lesions on saccacles contrasted with those observed in a second experiment requiring a key press response: FEF lesion patients were slower in making key press responses to signals detected in the contralesional field. To assess covert attention and preparatory set the effects of precues providing advance information were measured in both saccade and key press experiments. Neither patient group showed any deficiency in using precues to shift attention or to prepare saccades. The FEF facilitates the generation of voluntary saccatles and also inhibits reflexive saccades to exogenous signals. FEF lesions may disinhibit the ipsilesional midbrain which in turn may inhibit the opposite colliculus to slow reflexive saccades toward the ipsilesional field.


2017 ◽  
Vol 372 (1724) ◽  
pp. 20160343 ◽  
Author(s):  
Ryan J. Weaver ◽  
Rebecca E. Koch ◽  
Geoffrey E. Hill

Many of the colour displays of animals are proposed to have evolved in response to female mate choice for honest signals of quality, but such honest signalling requires mechanisms to prevent cheating. The most widely accepted and cited mechanisms for ensuring signal honesty are based on the costly signalling hypothesis, which posits that costs associated with ornamentation prevent low-quality males from being highly ornamented. Alternatively, by the index hypothesis, honesty can be achieved via cost-free mechanisms if ornament production is causally linked to core physiological pathways. In this essay, we review how a costly signalling framework has shaped empirical research in mate choice for colourful male ornaments and emphasize that alternative interpretations are plausible under an index signalling framework. We discuss the challenges in both empirically testing and distinguishing between the two hypotheses, noting that they need not be mutually exclusive. Finally, we advocate for a comprehensive approach to studies of colour signals that includes the explicit consideration of cost-free mechanisms for honesty. This article is part of the themed issue ‘Animal coloration: production, perception, function and application’.


2015 ◽  
Vol 282 (1816) ◽  
pp. 20151574 ◽  
Author(s):  
Matthew R. Wilkins ◽  
Daizaburo Shizuka ◽  
Maxwell B. Joseph ◽  
Joanna K. Hubbard ◽  
Rebecca J. Safran

Complex signals, involving multiple components within and across modalities, are common in animal communication. However, decomposing complex signals into traits and their interactions remains a fundamental challenge for studies of phenotype evolution. We apply a novel phenotype network approach for studying complex signal evolution in the North American barn swallow ( Hirundo rustica erythrogaster ). We integrate model testing with correlation-based phenotype networks to infer the contributions of female mate choice and male–male competition to the evolution of barn swallow communication. Overall, the best predictors of mate choice were distinct from those for competition, while moderate functional overlap suggests males and females use some of the same traits to assess potential mates and rivals. We interpret model results in the context of a network of traits, and suggest this approach allows researchers a more nuanced view of trait clustering patterns that informs new hypotheses about the evolution of communication systems.


2019 ◽  
Vol 374 (1781) ◽  
pp. 20180055 ◽  
Author(s):  
Ulrika Candolin ◽  
Bob B. M. Wong

Pollution (e.g. by chemicals, noise, light, heat) is an insidious consequence of anthropogenic activity that affects environments worldwide. Exposure of wildlife to pollutants has the capacity to adversely affect animal communication and behaviour across a wide range of sensory modalities—by not only impacting the signalling environment, but also the way in which animals produce, perceive and interpret signals and cues. Such disturbances, particularly when it comes to sex, can drastically alter fitness. Here, we consider how pollutants disrupt communication and behaviour during mate choice, and the ecological and evolutionary changes such disturbances can engender. We explain how the different stages of mate choice can be affected by pollution, from encountering mates to the final choice, and how changes to these stages can influence individual fitness, population dynamics and community structure. We end with discussing how an understanding of these disturbances can help inform better conservation and management practices and highlight important considerations and avenues for future research. This article is part of the theme issue ‘Linking behaviour to dynamics of populations and communities: application of novel approaches in behavioural ecology to conservation’.


2015 ◽  
Vol 282 (1800) ◽  
pp. 20141428 ◽  
Author(s):  
Katherine L. Barry

Animal communication theory holds that in order to be evolutionarily stable, signals must be honest on average, but significant dishonesty (i.e. deception) by a subset of the population may also evolve. A typical praying mantid mating system involves active mate searching by males, which is guided by airborne sex pheromones in most species for which mate-searching cues have been studied. The Femme Fatale hypothesis suggests that female mantids may be selected to exploit conspecific males as prey if they benefit nutritionally from cannibalism. Such a benefit exists in the false garden mantid Pseudomantis albofimbriata —females use the resources gained from male consumption to significantly increase their body condition and reproductive output. This study aimed to examine the potential for chemical deception among the subset of females most likely to benefit from cannibalism (poorly fed females). Females were placed into one of four feeding treatments (‘Very Poor’, ‘Poor’, ‘Medium’ and ‘Good’), and males were given the opportunity to choose between visually obscured females in each of the treatments. Female body condition and fecundity varied linearly with food quantity; however, female attractiveness did not. That is, Very Poor females attracted significantly more males than any of the other female treatments, even though these females were in significantly poorer condition, less fecund (in this study) and more likely to cannibalise (in a previous study). In addition, there was a positive correlation between fecundity and attractiveness if Very Poor females were removed from the analysis, suggesting an inherently honest signalling system with a subset of dishonest individuals. This is the first empirical study to provide evidence of sexual deception via chemical cues, and the first to provide support for the Femme Fatale hypothesis.


Behaviour ◽  
2000 ◽  
Vol 137 (12) ◽  
pp. 1655-1668 ◽  
Author(s):  
Peter McGregor ◽  
Claire Doutrelant

AbstractDespite the fact that most communication occurs in the context of networks of several individuals, the consequences of considering communication as a network on individuals' capacity for gathering information on congeners has been little investigated. Eavesdropping is the behaviour of a receiver extracting information from an interaction in which it is taking no part. Due to the fact that signals used in aggressive interactions are assumed to be reliable, eavesdropping could be an effective way of evaluating the quality of potential mates. We conducted two experiments designed to discover if female fighting fish (Betta splendens) monitor aggressive interactions between two males and if information gained by eavesdropping is used in the initial stages of subsequent mate choice. We found that females that had seen the interaction visited the winner first more often and spent significantly more time near, looking at and displaying to the winner of the interaction. By contrast females that had not seen the interaction visited the loser first more often and did not behave significantly differently to winner and loser. Overall these results are consistent with the idea that in the initial stages of mate choice females eavesdrop, i.e. use information gathered from male-male displays.


Author(s):  
Milovan Regodić ◽  
Christian F. Freyschlag ◽  
Johannes Kerschbaumer ◽  
Malik Galijašević ◽  
Romed Hörmann ◽  
...  

Abstract Purpose An auditory brainstem implant (ABI) represents an alternative for patients with profound hearing loss who are constrained from receiving a cochlear implant. The positioning of the ABI electrode influences the patient’s auditory capacity and, therefore, quality of life and is challenging even with available intraoperative electrophysiological monitoring. This work aims to provide and assess the feasibility of visual-spatial assistance for ABI positioning. Methods The pose of the forceps instrument that grasps the electrode was electromagnetically navigated and interactively projected in the eyepieces of a surgical microscope with respect to a target point. Intraoperative navigation was established with an experimental technique for automated nasopharyngeal patient registration. Two ABI procedures were completed in a human specimen head. Results An intraoperative usability study demonstrated lower localization error when using the proposed visual display versus standard cross-sectional views. The postoperative evaluations of the preclinical study showed that the center of the electrode was misplaced to the planned position by 1.58 mm and 3.16 mm for the left and the right ear procedure, respectively. Conclusion The results indicate the potential to enhance intraoperative feedback during ABI positioning with the presented system. Further improvements consider estimating the pose of the electrode itself to allow for better orientation during placement.


2018 ◽  
Author(s):  
Çağlar Akçay ◽  
Michelle L. Beck ◽  
Kendra B. Sewall

AbstractThe effect of urban noise on animal communication systems is one of the best examples of how anthropogenic change affects animal social behaviour. Urban noise often drives shifts in acoustic properties of signals but the consequences of noise for the honesty of signals – that is, how well they predict signaler behaviour, is unclear. Here we examine whether honesty of aggressive signaling changes in urban living song sparrows (Melospiza melodia). Aggressive signaling in song sparrows consists of close-range signals in two modalities that predict a subsequent attack: the low amplitude soft songs (an acoustic signal) and wing waves (a visual signal). Male song sparrows living in urban habitats display more territorial aggression than males living in rural habitats, but whether the honesty of close-range signals is affected by urbanization has not been examined. If soft songs are less effective in urban noise, we predict that they would be less reliably associated with attack in these habitats compared to rural habitats. We found that while acoustic noise was higher in urban habitats, the urban birds still sang more soft songs than rural birds during a simulated territorial intrusion. Furthermore, high rates of soft songs and low rates of loud songs predicted attacks in both habitats. Finally, we found evidence for a potential multimodal shift: urban birds tended to give proportionally more wing waves than soft songs than rural birds. These results indicate that urbanization might have a limited effect on the overall honesty of aggressive signals in song sparrows.


Author(s):  
Dustin Reichard ◽  
Marine Drouilly ◽  
Danielle Whittaker ◽  
Stephen Ferguson

The study of animal communication has been dominated by a focus on signal types that are easily recognized and quantified by human observers. This approach has inevitably limited our ability to identify cryptic signals such as low-amplitude vocalizations and signals that transmit beyond the range of our sensory system, such as most olfactory signals. Only recently with the development of new technologies and less biased sampling techniques have we begun to unravel the importance and function of these non-traditional signal types. Here we report the results of two experiments focusing on poorly studied signals using a common songbird, the dark-eyed junco. We investigated the effect of low-amplitude song on male physiology and the occurrence of bill-wiping behavior during courtship and aggressive interactions. Preliminary results suggest that males do not alter their plasma testosterone or corticosterone levels in response to a song playback of high-amplitude or low-amplitude song, indicating that a stronger stimulus may be necessary to affect circulating hormones. Males that received intrusions of a live male or female conspecific performed significantly more bill-wiping in response to the female conspecific, suggesting that bill-wiping may be an important and overlooked courtship signal in this species.


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