scholarly journals Evolution of bird communication signals: transference between signals mediated by sensory drive

2017 ◽  
Author(s):  
Oscar Laverde-R. ◽  
Michael J. Ryan ◽  
Carlos Daniel Cadena
Keyword(s):  
Vegetation Structure ◽  
Habitat Type ◽  
Negative Relationship ◽  
Visual Signals ◽  
High Rate ◽  
Costs And Benefits ◽  
Sensory Drive ◽  
Communication Signals ◽  
Song Variation ◽  
Sensory Modalities

Animals communicate using signals perceived via multiple sensory modalities but usually invest more heavily in one of type of signal. This pattern, observed by Darwin1 and many researchers since, led to development of the transfer hypothesis (see also transferal effect2 and tradeoff hypothesis3,4), which predicts a negative relationship between investment in different signaling modalities dictated by the relative costs and benefits of each. One factor that influences costs and benefits, and is central to the sensory drive hypothesis5 posed to account for signal evolution, is the suitability of the environment for different types of signals. Movement into a dark habitat, for example, should favor investment in acoustic over visual signals. We use phylogenetic comparative methods to analyze the joint effect of transfer and sensory drive on plumage and song variation in 52 species of a large radiation of passerine birds, the New World warblers (Parulidae), and to estimate temporal patterns in the accumulation of differences in visual and vocal signals and habitat along the evolutionary history of this lineage. We found evidence for the predicted negative correlations between a variety of song and plumage traits that vary with habitat type. Plumage contrast to background and chromatic diversity were both negatively related to syllable variety when vegetation structure was a covariate: birds with a greater variety of song syllables and less colorful plumages live in closed or darker habitats. Also as predicted, achromatic or brightness diversity was related to vegetation structure. In addition, disparity-through-time analyses showed that when one set of traits (i.e. songs or colors) diversified at a relatively high rate the other did not, as predicted by the transfer hypothesis. Our results show that sensory drive influences the transfer of investment between traits in different sensory modalities. This interaction between mechanisms shaping signals may be a major determinant in the evolution of animal communication.

scholarly journals Songs in the understory and colors in the canopy: habitat structure leads to different avian communication strategies in a tropical montane forest

2018 ◽  
Author(s):  
Oscar Laverde-R ◽  
Carlos Daniel Cadena
Keyword(s):  
Communication Strategies ◽  
Negative Relationship ◽  
Montane Forest ◽  
Tropical Montane Forest ◽  
Sensory Drive ◽  
Communication Signals ◽  
Forest Bird ◽  
Different Types ◽  
Bird Assemblage ◽  
Signaling Strategies

AbstractBirds inhabit a variety of habitats and they communicate using primarily visual and acoustic signals; two central hypotheses have been postulated to study the evolution of such a signals. The sensory drive hypothesis posits that variation in the physical properties of habitats leads to variation in natural selection pressures by affecting the ease with which different types of signals are perceived. Assuming that resources are limited for animals, the transfer hypothesis predicts a negative relationship between the investments in different types of signals. We evaluated these two hypotheses in a tropical montane forest bird assemblage. We also postulate a possible interaction between these two hypotheses: we predicted that the negative relationships between signals should be observed only when jointly considering birds from different environments (e.g. understory and canopy) due to the expected differences in communication strategies between habitats. The sensory drive hypothesis was supported by the differences we found between strata in vocal output, patch contrast to background and color conspicuousness, but not for the variables associated to song elaboration and hue disparity. We found support for the transfer hypothesis: birds with colors contrasting less against the background sing more frequently and birds with lower diversity of colors produce longer songs, understory birds showed also a negative relationship between signals, but only when accounting for phylogeny. We found partial support for the interaction between the sensory drive and the transfer hypotheses: hue disparity and vocal output were negatively related only when analyzing together birds from the canopy and the understory, but not when analyzing them separately. We conclude that the study of the evolution of communication signals needs to consider more than one channel and the functional interactions between them. The results of the interaction of optimal signaling strategies in two communication channels in the local habitats where animals signaling, are the patterns of colors and songs we revealed in a tropical montane forest bird assemblage.

scholarly journals Multi-modal signal evolution in birds: re-examining a standard proxy for sexual selection

2018 ◽  
Vol 285 (1889) ◽  
pp. 20181557 ◽  
Author(s):  
Christopher R. Cooney ◽  
Hannah E. A. MacGregor ◽  
Nathalie Seddon ◽  
Joseph A. Tobias
Keyword(s):  
Sexual Selection ◽  
Interspecific Interactions ◽  
Habitat Type ◽  
Negative Relationship ◽  
Key Factors ◽  
Phenotypic Data ◽  
Species Pairs ◽  
Multiple Alternative ◽  
Mating Signal ◽  
Diversification Hypothesis

Sexual selection is proposed to be an important driver of speciation and phenotypic diversification in animal systems. However, previous phylogenetic tests have produced conflicting results, perhaps because they have focused on a single signalling modality (visual ornaments), whereas sexual selection may act on alternative signalling modalities (e.g. acoustic ornaments). Here, we compile phenotypic data from 259 avian sister species pairs to assess the relationship between visible plumage dichromatism—a standard index of sexual selection in birds—and macroevolutionary divergence in the other major avian signalling modality: song. We find evidence for a strong negative relationship between the degree of plumage dichromatism and divergence in song traits, which remains significant even when accounting for other key factors, including habitat type, ecological divergence and interspecific interactions. This negative relationship is opposite to the pattern expected by a straightforward interpretation of the sexual selection–diversification hypothesis, whereby higher levels of dichromatism indicating strong sexual selection should be related to greater levels of mating signal divergence regardless of signalling modality. Our findings imply a ‘trade-off’ between the elaboration of visual ornaments and the diversification of acoustic mating signals, and suggest that the effects of sexual selection on diversification can only be determined by considering multiple alternative signalling modalities.

Influence of habitat on home-range size in the short-beaked echidna

2012 ◽  
Vol 60 (1) ◽  
pp. 46 ◽  
Author(s):  
Jenny Sprent ◽  
Stewart C. Nicol
Keyword(s):  
Home Range ◽  
Spatial Ecology ◽  
Habitat Type ◽  
Negative Relationship ◽  
Home Range Size ◽  
Range Size ◽  
Home Ranges ◽  
Location Data ◽  
Significant Negative Relationship ◽  
Solitary Species

The size of an animal’s home range is strongly influenced by the resources available within it. In productive, resource-rich habitats sufficient resources are obtainable within a smaller area, and for many species, home ranges are smaller in resource-rich habitats than in habitats with lower resource abundance. Location data on 14 male and 27 female echidnas (Tachyglossus aculeatus) fitted with tracking transmitters, in the southern midlands of Tasmania, were used to test the influence of habitat type on home-range size. We hypothesised that as woodland should offer more shelter, food resources and refuges than pasture, echidnas living in woodland would have smaller home ranges than those living in pasture areas. We found significant differences between the sexes. Male echidnas had a significantly larger mean home range than females and a quite different relationship between home-range size and habitat type from females. There was no relationship between the proportion of woodland within male home ranges and home-range size whereas female echidnas had a highly significant negative relationship. This suggests that home-range size of female echidnas is highly influenced by the amount of woodland within it, but the home-range size of male echidnas is controlled by factors other than habitat. This pattern is consistent with the spatial ecology of many other solitary species with a promiscuous mating system. The home ranges of females are scaled to encompass all necessary resources for successfully raising their young within a minimal area, whilst the large home ranges of males are scaled to maximise access to females.

scholarly journals Acoustic metrics predict habitat type and vegetation structure in the Amazon

2020 ◽  
Vol 117 ◽  
pp. 106679 ◽  
Author(s):  
Leandro A. Do Nascimento ◽  
Marconi Campos-Cerqueira ◽  
Karen H. Beard
Keyword(s):  
Vegetation Structure ◽  
Habitat Type

scholarly journals Processing bias: extending sensory drive to include efficacy and efficiency in information processing

2019 ◽  
Vol 286 (1900) ◽  
pp. 20190165 ◽  
Author(s):  
Julien P. Renoult ◽  
Tamra C. Mendelson
Keyword(s):  
Information Processing ◽  
Evolutionary Model ◽  
Metabolic Cost ◽  
Causal Link ◽  
Causal Chain ◽  
Signal Design ◽  
Sensory Drive ◽  
Communication Signals ◽  
Processing Bias ◽  
Emotional System

Communication signals often comprise an array of colours, lines, spots, notes or odours that are arranged in complex patterns, melodies or blends. Receiver perception is assumed to influence preference and thus the evolution of signal design, but evolutionary biologists still struggle to understand how perception, preference and signal design are mechanistically linked. In parallel, the field of empirical aesthetics aims to understand why people like some designs more than others. The model of processing bias discussed here is rooted in empirical aesthetics, which posits that preferences are influenced by the emotional system as it monitors the dynamics of information processing and that attractive signals have effective designs that maximize information transmission, efficient designs that allow information processing at low metabolic cost, or both. We refer to the causal link between preference and the emotionally rewarding experience of effective and efficient information processing as the processing bias, and we apply it to the evolutionary model of sensory drive. A sensory drive model that incorporates processing bias hypothesizes a causal chain of relationships between the environment, perception, pleasure, preference and ultimately the evolution of signal design, both simple and complex.

scholarly journals Multiple sensory modalities in diurnal geckos is associated with the signalling environment and evolutionary constraints

2020 ◽  
Author(s):  
Md Shakilur Kabir ◽  
Radhika Venkatesan ◽  
Maria Thaker
Keyword(s):  
Patch Size ◽  
Environmental Parameters ◽  
Habitat Associations ◽  
Visual Signals ◽  
Trade Off ◽  
Multimodal Signals ◽  
Trade Offs ◽  
Sensory Modalities ◽  
Chemical Traits ◽  
Signal Use

Abstract To be effective, animal signals need to be detectable in the environment, but their development and expression require resources. For multimodal communication, investment in elaborating traits in one modality could reduce the elaboration of traits in other modalities. In Cnemaspis geckos, chemical signals for conspecific communication pre-dated the evolution of visual signals, allowing us to examine the potential trade-off in signal elaboration and the current habitat associations with signal use. We studied five species of Cnemaspis and quantified visual (patch size, colour characteristics) and chemical (secretory composition) traits in males, as well as key environmental parameters (temperature, humidity, light) in each of their habitats. Within species, we found some trade-off in the elaboration of signals, as the strength of several components in the visual and chemical modalities were negatively associated. Strength of some signal components in each modality was also independently associated with specific environmental parameters that affect their detection (visual traits) and persistence (chemical traits). Specifically, species with larger, brighter, and more saturated colour patches were found in habitats where the brightness and chroma of light were lower. Furthermore, environments with higher substrate temperature and higher relative humidity harboured species that produced secretions with a higher percentage of saturated and aromatic compounds. Thus, the elaboration of multimodal signals in this group of Cnemaspis geckos seem to increase efficiency of communication in the signalling-environment, but the strength of signals in different modalities are constrained by trade-offs in signal expression.

scholarly journals Marine conservation of multispecies and multi-use areas with various conservation objectives and targets

2014 ◽  
Vol 72 (3) ◽  
pp. 851-862 ◽  
Author(s):  
Mara Schmiing ◽  
Hugo Diogo ◽  
Ricardo Serrão Santos ◽  
Pedro Afonso
Keyword(s):  
Site Selection ◽  
Management Practices ◽  
Marine Reserve ◽  
Reproductive Potential ◽  
Habitat Type ◽  
Fishing Effort ◽  
Marine Conservation ◽  
Costs And Benefits ◽  
Multiple Use ◽  
Spatial Management

Abstract Marine spatial management is an important step in regulating the sustainable use of marine resources and preserving habitats and species. The systematic conservation planning software “Marxan” was used to analyse the effect of different conservation objectives and targets on the design of a network of marine protected areas around two islands of the Azores archipelago, Northeast Atlantic. The analyses integrated spatial patterns of the abundance and reproductive potential of multispecies, the vulnerability of fish to fishing, habitat type, algae biotopes, and socio-economic costs and benefits (including fishing effort and recreational activities). Three scenarios focused on fisheries-related objectives (“fisheries scenarios”, FSs) and three on multiple-use and biodiversity conservation objectives (“biodiversity scenarios”, BSs), respectively. Three different protection targets were compared for each set, the existing, minimum, and maximum levels of protection, whereas conservation features were weighted according to their biologically/ecologically functioning. Results provided contrasting solutions for site selection and identified potential gaps in the existing design. The influence of the conservation objective on site selection was most evident when minimum target levels were applied. Otherwise, solutions for FSs and BSs were very similar and mostly shaped by the protection level. More important, BSs that considered opportunity cost and benefits achieved conservation targets more cost-efficiently. The presented systematic approach ensures that targets for habitats with high fish abundance, fecundity, and vulnerability are achieved efficiently. It should be of high applicability for adaptive management processes to improve the effectiveness of existing spatial management practices, in particular when fishing and leisure activities coexist, and suggest that decision-makers should account for multiple users’ costs and benefits when designing and implementing marine reserve networks.

Fast Reaction to Different Sensory Modalities Activates Common Fields in the Motor Areas, but the Anterior Cingulate Cortex is Involved in the Speed of Reaction

2000 ◽  
Vol 83 (3) ◽  
pp. 1701-1709 ◽  
Author(s):  
Eiichi Naito ◽  
Shigeo Kinomura ◽  
Stefan Geyer ◽  
Ryuta Kawashima ◽  
Per E. Roland ◽  
...  
Keyword(s):  
Reaction Time ◽  
Anterior Cingulate Cortex ◽  
Quantitative Methods ◽  
Cingulate Cortex ◽  
Motor Area ◽  
Anterior Cingulate ◽  
Visual Signals ◽  
Post Mortem ◽  
Sensory Modalities ◽  
Motor Areas

We examined which motor areas would participate in the coding of a simple opposition of the thumb triggered by auditory, somatosensory and visual signals. We tested which motor areas might be active in response to all three modalities, which motor structures would be activated specifically in response to each modality, and which neural populations would be involved in the speed of the reaction. The subjects were required to press a button with their right thumb as soon as they detected a change in the sensory signal. The regional cerebral blood flow (rCBF) was measured quantitatively with 15O-butanol and positron emission tomography (PET) in nine normal male subjects. Cytoarchitectural areas were delimited in 10 post mortem brains by objective and quantitative methods. The images of the post mortem brains subsequently were transformed into standard anatomic format. One PET scanning for each of the sensory modalities was done. The control condition was rest with the subjects having their eyes closed. The rCBF images were anatomically standardized, and clusters of significant changes in rCBF were identified. These were localized to motor areas delimited on a preliminary basis, such as supplementary motor area (SMA), dorsal premotor zone (PMD), rostral cingulate motor area (CMAr), and within areas delimited by using microstructural i.e., cytoarchitectonic criteria, such as areas 4a, 4p, 3a, 3b, and 1. Fields of activation observed as a main effect for all three modalities were located bilaterally in the SMA, CMAr, contralateral PMD, primary motor (M1), and primary somatosensory cortex (SI). The activation in M1 engaged areas 4a and 4p and expanded into area 6. The activation in SI engaged areas 3b, 1, and extended into somatosensory association areas and the supramarginal gyrus posteriorly. We identified significant activations that were specific for each modality in the respective sensory association cortices, though no modality specific regions were found in the motor areas. Fields in the anterior cingulate cortex, rostral to the CMAr, consistently showed significant negative correlation with mean reaction time (RT) in all three tasks. These results show that simple reaction time tasks activate many subdivisions of the motor cortices. The information from different sensory modalities converge onto the common structures: the contralateral areas 4a, 4p, 3b, 1, the PMD, and bilaterally on the SMA and the CMAr. The anterior cingulate cortex might be a key structure which determine the speed of reaction in simple RT tasks.

scholarly journals Manipulating territory size via vegetation structure: optimal size of area guarded by the convict cichlid (Pisces, Cichlidae)

2002 ◽  
Vol 80 (2) ◽  
pp. 376-380 ◽  
Author(s):  
Cindy Breau ◽  
James WA Grant
Keyword(s):  
Growth Rates ◽  
Vegetation Structure ◽  
Cichlid Fish ◽  
Territory Size ◽  
Optimal Size ◽  
Convict Cichlid ◽  
Food Patch ◽  
Costs And Benefits ◽  
Archocentrus Nigrofasciatus ◽  
Data Support

To test the predictions of optimal territory size models, we attempted to manipulate the size of area that a dominant convict cichlid fish (Archocentrus nigrofasciatus) would defend around a food patch by placing simulated vegetation at three different distances from the edge of the patch (0, 11, and 22 cm). As expected, the size of area defended against four smaller intruders increased as the vegetation was moved farther from the patch. Consistent with optimal territory size models, both the costs of defence, measured as chase radius and chase rate, and the benefits of defence, measured as the amount of food eaten by the defender, increased with the distance of the vegetation from the patch. Growth rates of the defenders, however, did not differ among the treatments, perhaps because the benefits of monopolizing food were balanced by the costs of defending a larger area. Our data support the hypothesis that the size of a guarded area around an ephemeral resource patch affects both the costs and benefits of defence.

scholarly journals Lizards speed up visual displays in noisy motion habitats

2007 ◽  
Vol 274 (1613) ◽  
pp. 1057-1062 ◽  
Author(s):  
Terry J Ord ◽  
Richard A Peters ◽  
Barbara Clucas ◽  
Judy A Stamps
Keyword(s):  
Puerto Rican ◽  
Background Noise ◽  
Visual Signals ◽  
Acoustic Properties ◽  
Masking Effect ◽  
Environmental Constraints ◽  
Visual Displays ◽  
Noisy Environments ◽  
Communication Signals ◽  
Speed Up

Extensive research over the last few decades has revealed that many acoustically communicating animals compensate for the masking effect of background noise by changing the structure of their signals. Familiar examples include birds using acoustic properties that enhance the transmission of vocalizations in noisy habitats. Here, we show that the effects of background noise on communication signals are not limited to the acoustic modality, and that visual noise from windblown vegetation has an equally important influence on the production of dynamic visual displays. We found that two species of Puerto Rican lizard, Anolis cristatellus and A. gundlachi , increase the speed of body movements used in territorial signalling to apparently improve communication in visually ‘noisy’ environments of rapidly moving vegetation. This is the first evidence that animals change how they produce dynamic visual signals when communicating in noisy motion habitats. Taken together with previous work on acoustic communication, our results show that animals with very different sensory ecologies can face similar environmental constraints and adopt remarkably similar strategies to overcome these constraints.

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