Indirect Cues Research Articles

Monitoring temporal change of bird communities with dissimilarity acoustic indices

Summary A part of biodiversity assessment and monitoring consists in the estimation and track of the changes in species composition and abundance of animal communities. Such a task requires an important sampling over a broad‐scale time that is difficult to reach with classical survey methods. Acoustics may offer an alternative to usual techniques by recording the sound produced by vocal animals. Animal species that use sound for communication (sing and/or call) establish an acoustic community when they sing at the same time and at a particular place. The estimation of the acoustic community dynamics could provide indirect cues on what drives changes in community composition and species abundance. Here, new methods were developed to estimate the changes in bird communities recorded at three woodland temperate sites in France. Both field recordings and simulated data were used to test whether acoustic dissimilarity indices can be used to estimate changes in the composition of the community. Four dissimilarity indices found in the literature, and a new one named Dcf were tested on auditory spectra after transformation to the Mel scale, rather than on classical Fourier frequency spectra. All indices were compared with each other and with compositional indices. The results show that bird communities occurring at the three sites were dynamic with changes of composition with time. Dissimilarities computed on simulated acoustic communities were correlated with compositional dissimilarity but those computed on field‐recorded communities could not be considered as faithful estimators of community composition variations. However, the indices indicate important dates in community changes around mid‐April that were also seen in the composition dynamics. Acoustic dissimilarity indices failed to track accurately changes in species composition of the bird communities. However, these indices, which are easy to compute, still provide information on the acoustic dynamics of bird community. Acoustics might not be considered as a proxy of compositional diversity but rather as another facet of animal diversity that needs to be studied and preserved on its own.

Social cues are preferred over resource cues for breeding-site selection in Barn Swallows

AbstractTo maximize fitness, animals choose habitats by using a combination of direct resource cues, such as the quality and quantity of safe breeding sites or food resources, and indirect social cues, such as the presence or breeding performance of conspecifics. Many reports show that nest predation leads to reduced fitness. However, it remains unclear how birds assess predation risk and how it affects breeding-site selection. In this study, we analyzed the relationship between predation risk and breeding-site selection in Barn Swallows (Hirundo rustica). We assessed the cues that swallows use in their selection. We used nest-site characteristics related to predation and foraging sites as direct resource cues, number of breeding pairs, and breeding success in the previous year as indirect social cues, and number of old and undamaged old nests as direct resource and/or indirect social cues. Breeding-site preference was assessed using the arrival date of males. We showed that only the number of undamaged old nests was used for breeding-site selection. When comparing effects at two spatial scales, nest-site and home-range, the effect of the number of undamaged old nests occurred at the home-range scale only, suggesting that these nests are used as an indirect social cue rather than a direct resource cue to reduce the energy or time-consuming costs of nest building. We suggest that undamaged old nests may indicate the presence and breeding performance of conspecifics for several previous years. Because Barn Swallows are migratory birds, undamaged old nests may be a reliable indirect social cue and may reduce the time required to sample information at breeding sites.

The Spread of Fear: Symbolic Generalization Mediates Graded Threat-Avoidance in Specific Phobia

Overgeneralization of fear and threat-avoidance represents a formidable barrier to successful clinical treatment of anxiety disorders. While stimulus generalization along quantifiable physical dimensions has been studied extensively, less consideration has been given to symbolic generalization, in which stimuli are indirectly and arbitrarily related. The present study examined whether the magnitude and extent of symbolic generalization of threat-avoidance and threat-beliefs differed between spider-phobic and nonphobic individuals. Initially, participants learned two sets of stimulus equivalence relations (A1 = B1 = C1; A2 = B2 = C2). Next, one cue (B1) was established as a conditioned stimulus (CS + ; threat) that signalled onset of spider images and prompted avoidance, and another cue (B2) was established as a CS- (safety cue) that signalled the absence of such images. Subsequent testing showed that phobics compared to nonphobics exhibited greater symbolic generalization of threat-avoidance to threat cues A1 and C1 (indirect CS+ threat cues related via symmetry and equivalence, respectively), while all individuals showed nonavoidance to indirect safety cues A2 and C2. The enhanced symbolic generalization of threat-beliefs and avoidance behaviour observed in spider phobics warrants further investigation.

Encoding destination messages in media coverage of an international event: A case study of the European athletics indoor championships

Abstract The destination management strategy of enhancing destination brands or market position via international sport events is one of the main reasons for destinations to engage in event bidding. The strategy raises important questions regarding the process of encoding a destination's brand values into the media reports from an international sporting event and what the perceived challenges of that strategy are. The process has been explored from a destination perspective in a case study during the recently completed 2013 European Athletics Indoor Championships in Gothenburg, Sweden using data from multiple sources before, during and after the event. Public relations strategy and the persuasive communication model have been employed to structure the description. The study shows that the destination marketing organization (DMO) is involved in two different processes in order to influence the message transmitted from the event. The TV broadcast process is negotiated before the event and the news coverage process is occurring during the event. The latter relates to the DMO's attempts to persuade gatekeepers of international media to include the destination message in their reports by the use of both direct and indirect cues and activities. One tenth of the reports from the event are about the destination rather than the sport. Key differences between the two processes are presented, as well as a synthesis model of information-based communication and persuasive communication in the setting of an international sport event. Challenges to the strategy were e.g. media professional's formal assignment and the match between event and destination values in order for the DMO to communicate a newsworthy message.

Sharing a driver's context with a caller via continuous audio cues to increase awareness about driver state.

In an experiment using a driving simulator we investigated whether sharing information of a driver's context with a remote caller via continuous audio cues can make callers more aware of the driving situation. Increased awareness could potentially help in making the conversation less distracting. Prior research has shown that although sharing context using video can create such beneficial effects, it also has some practical disadvantages. It is an open question whether other modalities might also provide sufficient context for a caller. In particular, the effects of sharing audio, a cheaper, more salient, and perhaps more practical alternative than video, are not well understood. We investigated sharing context using direct cues in the form of realistic driving sounds (e.g., car honks, sirens) and indirect cues in the form of elevated heartbeats. Sound sharing affected the caller's perception of the driver's busyness. However, this had at most a modest effect on conversation and driving performance. An implication of these results is that although sharing sounds can increase a caller's awareness of changes in the driver's busyness, they need more training or information on how to leverage such context information to reduce disruption to driving. Limitations and implications are discussed.

Indirect cues in selecting a hunting site in a sit‐and‐wait predator

AbstractSit‐and‐wait predators use relatively simple rules for their decisions to choose and leave a patch, such as using the direct presence of prey to select a hunting site. However, the direct presence of prey can only be used when there is a highly visited patch in the proximity of the predator. Therefore, it is plausible that sit‐and‐wait predators also exploit indirect cues of prey presence and, consequently, use associative learning to select a hunting site. The present study tests for the role of associative learning in a sit‐and‐wait predator species for which the ecology is well understood: Misumena vatia Clerck crab spiders. An ecologically relevant scenario is used by selecting flower colour as the conditioned stimulus and prey presence as the unconditioned stimulus. The results provide no evidence that M. vatia crab spiders use the association between flower colour and food presence for selecting a hunting site. After a training phase of being exposed to a colourful artificial flower highly visited by bees, spiders select a hunting site independently of its colour during the testing phase. Investigations of similar scope and ecological relevance are required with other sit‐and‐wait predators to identify the conditions promoting the use of associative learning for foraging site selection when animals face an unpredictable food supply.

Indirect cueing elicits distinct types of autobiographical event representations

Studies that distinguish among believed memories, believed-not-remembered events (e.g., family stories), and nonbelieved memories (i.e., memories no longer believed to have occurred) typically rely on experimenter provided or overtly elicited events. These methods may mis-estimate the frequency and nature of such events in everyday memory. Three studies examined whether such events would be elicited via indirect cueing. Participants recalled and rated events on autobiographical belief, recollection, and other characteristics associated with remembering. All three event types resulted, but with a low rate of nonbelieved memories. Believed and nonbelieved memories received similar perceptual and re-experiencing ratings, and both exceeded believed-not-remembered events. Lifespan cueing found nonbelieved memories to be most frequent in middle childhood (ages 6-11). Cueing for "events" vs. "memories" revealed that "memory" cues lead to retrieval of a more homogeneous set of events and differences when predicting autobiographical belief and recollection. These studies support the distinction between autobiographical belief and recollection for autobiographical events.

The algebra of fatherhood

Abstract Whereas women are sure of their biological maternity, men can never be fully certain of paternity and instead need to rely on indirect cues to assess whether they are likely to be father of their putative children. According to the psychological literature, men commonly use the information on the resemblance of offspring to self as an indicator of genetic relatedness. It seems, however, that in the absence of such a resemblance, similarity between a mother and a child might be important, because a man has additional reason to doubt his own biological paternity when the child is dissimilar to his partner. This assumption has been verified in two empirical studies.

Phenotypic plasticity in a generalist insect herbivore with the combined use of direct and indirect cues

Ultimate causes of phenotypic plasticity in visual appearance are frequently related to increasing the degree of crypsis in a way specific to the environment. The cues used to elicit such plastic responses may be both direct (i.e. straightforward background matching) as well as indirect. In the latter case, cues other than the visual signals from of the environment are used to predict the phenotype best corresponding to the particular situation. On the basis of a series of laboratory experiments we show that the remarkable variability in the visual appearance of the larvae of the geometrid moth Ematurga atomaria, though genetically based in part, involves a substantial environmental component. Using multiple correspondence analysis, we transformed the multidimensional variation in colour and pattern into two dimensions interpretable as patterning and darkness. Plastic changes in the darkness of the larvae were elicited by direct cues: the larvae were darker when reared on dark host‐plants. Host‐specific degree of patterning was also induced in absolute darkness which indicates the use of an indirect cue. This was unexpected because the study species is broadly polyphagous, and thus not likely to have evolved adaptations specific to particular host‐plant species. Indeed, the larvae of E. atomaria originating from geographic populations using different host‐plants showed analogous plastic responses which indicates that the link between the indirect cue and visual appearance of the host needs not to be specific to plant species. In an additional experiment, we showed that surface roughness is a likely candidate to serve as the proximate cue for determination of some pattern elements, a case not reported for insect larvae earlier.

From repulsion to attraction: species- and spatial context-dependent threat sensitive response of the spider mite Tetranychus urticae to predatory mite cues

Prey perceiving predation risk commonly change their behavior to avoid predation. However, antipredator strategies are costly. Therefore, according to the threat-sensitive predator avoidance hypothesis, prey should match the intensity of their antipredator behaviors to the degree of threat, which may depend on the predator species and the spatial context. We assessed threat sensitivity of the two-spotted spider mite, Tetranychus urticae, to the cues of three predatory mites, Phytoseiulus persimilis, Neoseiulus californicus, and Amblyseius andersoni, posing different degrees of risk in two spatial contexts. We first conducted a no-choice test measuring oviposition and activity of T. urticae exposed to chemical traces of predators or traces plus predator eggs. Then, we tested the site preference of T. urticae in choice tests, using artificial cages and leaves. In the no-choice test, T. urticae deposited their first egg later in the presence of cues of P. persimilis than of the other two predators and cue absence, indicating interspecific threat-sensitivity. T. urticae laid also fewer eggs in the presence of cues of P. persimilis and A. andersoni than of N. californicus and cue absence. In the artificial cage test, the spider mites preferred the site with predator traces, whereas in the leaf test, they preferentially resided on leaves without traces. We argue that in a nonplant environment, chemical predator traces do not indicate a risk for T. urticae, and instead, these traces function as indirect habitat cues. The spider mites were attracted to these cues because they associated them with the existence of a nearby host plant.

From Coming Out to Visibility Management—A New Perspective on Coping With Minority Stressors in LGB Youth in Flanders

This article develops a model that describes relations among environmental characteristics, discrimination and visibility management, and the experience of minority stressors by lesbian, gay, and bisexual (LGB) youth. The article elaborates on how visibility management (i.e., regulating the exposure of one's sexual orientation) of LGB youth can function as a coping strategy and is, therefore, closely tied to the experience of minority stressors. Qualitative support is found for the theoretical model in conducting 24 in-depth interviews with LGB youth. The analysis also shows that LGB youth use specific mannerisms, gender-nonconformist behaviors, and other indirect cues to make themselves visible or invisible as LGBs.

Juvenile crab spiders (Mecaphesa asperata) use indirect cues to choose foraging sites

Direct assessment of food resources may be unreliable if those resources fluctuate or are not easily detected. Foragers under such conditions may instead use indirect cues to assess the quality of potential foraging sites. Young individuals may be particularly likely to use indirect cues to compensate for their inexperience and to reduce assessment costs. We investigated the cues juvenile crab spiders (Mecaphesa asperata) use when selecting foraging sites. First, we examined whether spiderlings' site preference was influenced by prey abundance, a direct cue of site quality. We next investigated whether juvenile crab spiders assessed potential sites using indirect cues, including flower quality, cues left by conspecifics, or conspecifics themselves. We found spiderlings did not use prey abundance to assess foraging sites, but instead used indirect cues when choosing where to forage. Spiderlings preferred sites that would attract larger numbers of their arthropod prey, choosing blooming inflorescences over both senescing inflorescences and inflorescences with buds. Hungry spiderlings, unlike individuals that had recently fed, also used cues left by conspecifics, preferring sites on which a conspecific had previously foraged. Finally, spiderlings avoided sites with larger numbers of conspecifics, but were attracted to sites with relatively low abundances of conspecifics, indicating that spiderlings are able to weigh the possibility of improving their foraging success by joining conspecifics against the potential costs of being in larger groups. We show here that young, relatively inexperienced animals do not always directly assess prey abundance when choosing foraging sites, but that these individuals are capable of detecting and using a variety of indirect cues to evaluate foraging site quality.

Characterizing healthy and osteoarthritic knee cartilage on phase contrast CT with geometric texture features.

The current approach to evaluating cartilage degeneration at the knee joint requires visualization of the joint space on radiographic images where indirect cues such as joint space narrowing serve as markers for osteoarthritis. A recent novel approach to visualizing the knee cartilage matrix using phase contrast imaging (PCI) with computed tomography (CT) was shown to allow direct examination of chondrocyte patterns and their subsequent correlation to osteoarthritis. This study aims to characterize chondrocyte cell patterns in the radial zone of the knee cartilage matrix in the presence and absence of osteoarthritic damage through texture analysis. Statistical features derived from gray-level co-occurrence matrices (GLCM) and geometric features derived from the Scaling Index Method (SIM) were extracted from 404 regions of interest (ROI) annotated on PCI images of healthy and osteoarthritic specimens of knee cartilage. These texture features were then used in a machine learning task to classify ROIs as healthy or osteoarthritic. A fuzzy k-nearest neighbor classifier was used and its performance was evaluated using the area under the Receiver Operating Characteristic (ROC) curve (AUC). The best classification performance was observed with high-dimensional geometrical feature vectors derived from SIM and GLCM correlation features. With the experimental conditions used in this study, both SIM and GLCM achieved a high classification performance (AUC value of 0.98) in the task of distinguishing between healthy and osteoarthritic ROIs. These results show that such quantitative analysis of chondrocyte patterns in the knee cartilage matrix can distinguish between healthy and osteoarthritic tissue with high accuracy.

Differential Neural Activation Patterns in Patients with Parkinson's Disease and Freezing of Gait in Response to Concurrent Cognitive and Motor Load

Freezing of gait is a devastating symptom of Parkinson's disease (PD) that is exacerbated by the processing of cognitive information whilst walking. To date, no studies have explored the neural correlates associated with increases in cognitive load whilst performing a motor task in patients with freezing. In this experiment, 14 PD patients with and 15 PD patients without freezing of gait underwent 3T fMRI while performing a virtual reality gait task. Directions to walk and stop were presented on the viewing screen as either direct cues or as more cognitively indirect pre-learned cues. Both groups showed a consistent pattern of BOLD response within the Cognitive Control Network during performance of the paradigm. However, a between group comparison revealed that those PD patients with freezing of gait were less able to recruit the bilateral anterior insula, ventral striatum and the pre-supplementary motor area, as well as the left subthalamic nucleus when responding to indirect cognitive cues whilst maintaining a motor output. These results suggest that PD patients with freezing of gait are unable to properly recruit specific cortical and subcortical regions within the Cognitive Control Network during the performance of simultaneous motor and cognitive functions.

Vigilance of kit foxes at water sources: A test of competing hypotheses for a solitary carnivore subject to predation

Animals that are potential prey do not respond equally to direct and indirect cues related to risk of predation. Based on differential responses to cues, three hypotheses have been proposed to explain spatial variation in vigilance behavior. The predator-vigilance hypothesis proposes that prey increase vigilance where there is evidence of predators. The visibility-vigilance hypothesis suggests that prey increase vigilance where visibility is obstructed. Alternatively, the refuge-vigilance hypothesis proposes that prey may perceive areas with low visibility (greater cover) as refuges and decrease vigilance. We evaluated support for these hypotheses using the kit fox (Vulpes macrotis), a solitary carnivore subject to intraguild predation, as a model. From 2010 to 2012, we used infrared-triggered cameras to record video of kit fox behavior at water sources in Utah, USA. The refuge-vigilance hypothesis explained more variation in vigilance behavior of kit foxes than the other two hypotheses (AICc model weight=0.37). Kit foxes were less vigilant at water sources with low overhead cover (refuge) obstructing visibility. Based on our results, the predator-vigilance and visibility-vigilance hypotheses may not be applicable to all species of prey. Solitary prey, unlike gregarious prey, may use areas with concealing cover to maximize resource acquisition and minimize vigilance.

Effectiveness of Artificial Song Playback on Influencing the Settlement Decisions of an Endangered Resident Grassland Passerine

Abstract. Social information in the form of songs, calls, or other overt behaviors may assist birds in assessing the quality of potential breeding habitat by providing direct public information about a site's quality or by providing indirect cues (e.g., the presence of conspecifics) that may be used to infer its quality. Broadcast of song has been used to demonstrate the influence of conspecific cues on the decisions of migratory passerines to settle; however, there is currently a dearth of information regarding resident species. We tested the influence of conspecific attraction and the effectiveness of song playback on an endangered resident of grassland, the Cape Sable Seaside Sparrow (Ammodramus maritimus mirabilis). We broadcast recorded song over large areas of suitable breeding habitat in the Florida Everglades in an attempt to influence the settlement of male sparrows during territory establishment. Our analyses included the creation of a qualitative sound map that formed a basis for measuring the ...

Responding to Lexical Stimuli With Gender Associations

This article presents a cognitive–cultural model (CC model) of situational, dispositional, and motivational factors affecting gender-associational responses to lexical expressions concerning people. It is argued that the mind is trained to perceive gender as an indispensable human feature. When decoding the meaning of a message, it will search for cues of gender, usually prioritizing the semantic content. When gender is not clearly specified, the mind attempts to plausibly reconstruct missing data by referring to indirect extrasemantic cues. This often occurs beyond conscious recognition. Lexical cues are strongly influential owing to their direct association with semantic gender-specific meaning. Gender-associational dispositions resulting from cognitive training also affect the response. This article discusses cognitive training’s cultural, gender-related, and individual components, along with dispositional and incidental factors, affecting motivation to consciously authorize and/or alter the initial automatic response.

Homing in rocky intertidal fish. Are Lipophrys pholis L. able to perform true navigation?

Although navigation is common in many animals, only a few perform true navigation, meaning that they have the ability to return to a given place by relying on indirect cues obtained at the release site (i.e., by relying on information from a "map and compass" mechanism). The common intertidal fish, Lipophrys pholis, is thought to have homing abilities through a mechanism that primarily makes use of familiar landmarks (i.e., piloting). Anecdotal reports that individuals return to their home pools after release at unfamiliar sites suggest that L. pholis might use cues collected at the release site to find their way back (i.e., they might use map and compass information). Using a completely artificial setup, we tested the homing abilities of L. pholis as a function of age, sex, and familiarity with the release site. The findings showed that motivation for homing is present only in the adult phase and is independent of sex and/or familiarity with the release site. Moreover, adults released at a completely unfamiliar place oriented themselves in a direction roughly similar to that of their home pools. The fact that L. pholis were tested in a complete artificial environment means that hydrodynamic cues can be excluded as playing a role in this process and restricts the candidate options (e.g., magnetic cues). The ability to perform navigation based on a "map and compass" mechanism raises many interesting questions about the learning process, once these individuals have restricted home ranges during their lives. In vertebrate navigation, the cues used during the navigation process are a question of debate, and L. pholis offers an outstanding model to test hypotheses and ultimately provide answers.

Do Brooding Pythons Recognize their Clutches? Investigating External Cues for Offspring Recognition in the Children's Python, Antaresia childreni

AbstractParental care provides substantial benefits to offspring but exacts a high cost to parents, necessitating the evolution of offspring recognition systems when the risk of misdirected care is high. In species that nest, parents can use cues associated with the offspring (direct offspring recognition) or the nest (indirect offspring recognition) to reduce the risk of misdirected care. Pythons have complex parental care, but a low risk of misdirected care. Thus, we hypothesized that female Children's pythons (Antaresia childreni) use indirect cues to induce and maintain brooding behavior. To test this, we used a series of five clutch manipulations to test the importance of various external brooding cues. Contrary to our hypothesis, we found that female A. childreni are heavily internally motivated to brood, needing only minimal external cues to induce and maintain egg‐brooding behavior. Females were no more likely to brood their own clutch in the original nest as they were to brood a clutch from a conspecific, a pseudoclutch made from only the shells of a conspecific, or their clutch in a novel nest. The only scenario where brooding was reduced, but even then not eliminated, was when the natural clutch was replaced with similarly sized stones. These results suggest that egg recognition in pythons is similar to that of solitary‐nesting birds, which have similar nesting dynamics.

Women’s body movements are a potential cue to ovulation

Recent evidence suggests that the concept of ‘concealed ovulation’ in women should be reconsidered, as there appear to be certain behavioural, visual, olfactory, and vocal cues that serve as indirect cues to female fertility. Here we test the hypothesis that men are able to discern fertile from non-fertile women based on their dance and gait movements. Digital videos of dances and gaits of 48 heterosexual women, aged 19–33years, were recorded twice, once in the late follicular phase, and once in the mid-luteal phase of their menstrual cycle. Short video clips comprising movement silhouettes of dances and gaits were judged on attractiveness by a total of 200 men. Dances and gaits recorded in the late follicular were rated significantly more attractive compared to recordings in the mid-luteal phase. We suggest that (i) menstrual cycle effects on women’s body movements exist, and (ii) men are sensitive to these effects, as they expressed a stronger preference (via attractiveness judgments) for women’s body movements at times of peak fertility. Our data add body movements to the list of features that show systematic changes across the menstrual cycle and support the assertion that men are able to detect cues of female fertility.