The Experts below are selected from a list of 879 Experts worldwide ranked by ideXlab platform
Christopher S. Evans - One of the best experts on this subject based on the ideXlab platform.
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Silent tidbitting in male fowl, Gallus gallus: a referential visual signal with multiple functions.
Journal of Experimental Biology, 2009Co-Authors: Carolynn L. Smith, Christopher S. EvansAbstract:With the notable exception of Bee Dances, there are no established examples of multimodal referential signals. The food calls of male fowl, Gallus gallus, are functionally referential and the acoustic component of a multimodal display. However, the specificity of the receiver's response to the visual component (tidbitting) has never Been tested. Here we provide the first detailed analysis of tidbitting, and test the hypothesis that these characteristic movements are functionally referential. We conducted a playback experiment with five high-definition video stimuli: Silent tidbit, Matched-frequency motion in the opposite direction, Silent crows, Inactive male and Empty cage. Females searched for food more during Silent tidbitting than under any other condition, suggesting that this visual display specifically predicts the presence of food and hence has similar functional properties to food calls. Silent tidbitting was also singularly effective at evoking approach and close inspection, which may enhance signal memorability. These social responses suggest that the visual component of the display has the unique function of triggering assessment of signaler identity and quality as a potential mate. The acoustic and visual components are hence redundant as a food signal, but synergistic when additional functions are considered. These findings emphasize the perceptual complexity of multimodal displays and provide the first demonstration of multimodal referential signaling in a vertebrate.
Carolynn L. Smith - One of the best experts on this subject based on the ideXlab platform.
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Silent tidbitting in male fowl, Gallus gallus: a referential visual signal with multiple functions.
Journal of Experimental Biology, 2009Co-Authors: Carolynn L. Smith, Christopher S. EvansAbstract:With the notable exception of Bee Dances, there are no established examples of multimodal referential signals. The food calls of male fowl, Gallus gallus, are functionally referential and the acoustic component of a multimodal display. However, the specificity of the receiver's response to the visual component (tidbitting) has never Been tested. Here we provide the first detailed analysis of tidbitting, and test the hypothesis that these characteristic movements are functionally referential. We conducted a playback experiment with five high-definition video stimuli: Silent tidbit, Matched-frequency motion in the opposite direction, Silent crows, Inactive male and Empty cage. Females searched for food more during Silent tidbitting than under any other condition, suggesting that this visual display specifically predicts the presence of food and hence has similar functional properties to food calls. Silent tidbitting was also singularly effective at evoking approach and close inspection, which may enhance signal memorability. These social responses suggest that the visual component of the display has the unique function of triggering assessment of signaler identity and quality as a potential mate. The acoustic and visual components are hence redundant as a food signal, but synergistic when additional functions are considered. These findings emphasize the perceptual complexity of multimodal displays and provide the first demonstration of multimodal referential signaling in a vertebrate.
Francis L. W. Ratnieks - One of the best experts on this subject based on the ideXlab platform.
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Foraging of honey Bees in agricultural landscapes with changing patterns of flower resources
Agriculture Ecosystems & Environment, 2020Co-Authors: Svenja Bänsch, Francis L. W. Ratnieks, Stephan Härtel, Teja Tscharntke, Catrin WestphalAbstract:Abstract The demand for crop pollination is increasing and honey Bees are frequently used, in particular as wild pollinators are in decline. Temporal and spatial variation of flower resources affects foraging decisions of wild and honey Bees. To optimise crop pollination management a better understanding of potential competition for pollinators in mass- and minor-flowering crops is needed. We combined waggle dance decoding, pollen load analysis and field surveys to identify the habitat preferences and pollen use of honey Bees in response to spatio-temporal changes in resource availability. Observation hives were placed on the edge of eleven fields of blooming strawberries (mean 2.24 ha) located in landscapes with different amounts of oilseed rape (OSR), semi-natural habitats (SNH) and apple trees in Germany. In addition, we surveyed honey Bees and wild Bees in strawberry fields. Honey Bee Dances more often indicated strawberry, OSR fields and SNH than expected given their landscape-wide areas. Honey Bees collected on average 7.9 % strawberry, 49.0 % OSR, 30.2 % Pyrus type (e.g. apple) and 12.9 % other pollen types. The mean honey Bee foraging distance was 740 m, and decreased with OSR availability. In the observation hives, Dances for strawberry fields were not directly affected by OSR availability or SNH land cover. But large amounts of OSR reduced overall honey Bee and bumble Bee abundance in strawberry fields, while solitary Bees were unaffected. Bumble Bees were most abundant in strawberry fields (54.1%) and together with solitary Bees (19.7%) they represented about 75.0% of the observed Bees. Minor-flowering strawberry fields represent a preferred resource for honey Bees, especially for small colonies as indicated by decoding of waggle Dances. However, the availability of more attractive OSR and local strawberry flower cover moderates the abundance of social Bees (honey Bees and bumble Bees) in strawberry fields while other wild Bees were less affected. Hence, we conclude that wild Bee conservation plays a major role for strawberry pollination. If pollination services by solitary Bees are limited, small honey Bee hives can be used scrupulously to supplement pollination services in strawberries.
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Working against gravity: horizontal honeyBee waggle runs have greater angular scatter than vertical waggle runs
Biology letters, 2012Co-Authors: Margaret J. Couvillon, Hunter L. F. Phillipps, Roger Schürch, Francis L. W. RatnieksAbstract:The presence of noise in a communication system may be adaptive or may reflect unavoidable constraints. One communication system where these alternatives are debated is the honeyBee (Apis mellifera) waggle dance. Successful foragers communicate resource locations to nest-mates by a dance comprising repeated units (waggle runs), which repetitively transmit the same distance and direction vector from the nest. Intra-dance waggle run variation occurs and has Been hypothesized as a colony-level adaptation to direct recruits over an area rather than a single location. Alternatively, variation may simply be due to constraints on Bees' abilities to orient waggle runs. Here, we ask whether the angle at which the Bee Dances on vertical comb influences waggle run variation. In particular, we determine whether horizontal Dances, where gravity is not aligned with the waggle run orientation, are more variable in their directional component. We analysed 198 Dances from foragers visiting natural resources and found support for our prediction. More horizontal Dances have greater angular variation than Dances performed close to vertical. However, there is no effect of waggle run angle on variation in the duration of waggle runs, which communicates distance. Our results weaken the hypothesis that variation is adaptive and provide novel support for the constraint hypothesis.
Frank Dellaert - One of the best experts on this subject based on the ideXlab platform.
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Data-Driven MCMC for Learning and Inference in Switching Linear Dynamic Systems
2015Co-Authors: Sang Min, Oh James, M. Rehg, Tucker Balch, Frank DellaertAbstract:Switching Linear Dynamic System (SLDS) models are a popular technique for modeling complex nonlinear dy-namic systems. An SLDS has significantly more descriptive power than an HMM, but inference in SLDS models is computationally intractable. This paper describes a novel inference algorithm for SLDS models based on the Data-Driven MCMC paradigm. We describe a new proposal distribution which substantially increases the convergence speed. Comparisons to standard deterministic approximation methods demonstrate the improved accuracy of our new approach. We apply our approach to the problem of learning an SLDS model of the Bee dance. HoneyBees communi-cate the location and distance to food sources through a dance that takes place within the hive. We learn SLDS model parameters from tracking data which is automatically extracted from video. We then demonstrate the ability to successfully segment novel Bee Dances into their constituent parts, effectively decoding the dance of the Bees
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Learning and Inference in Parametric Switching Linear Dynamic Systems
2008Co-Authors: Sang Min, Oh James, M. Rehg, Tucker Balch, Frank DellaertAbstract:We introduce parametric switching linear dynamic systems (P-SLDS) for learning and interpretation of parametrized motion, i.e., motion that exhibits systematic temporal and spatial variations. Our motivating example is the honeyBee dance: Bees communicate the orientation and distance to food sources through the dance angles and waggle lengths of their stylized Dances. Switching linear dynamic systems (SLDS) are a compelling way to model such complex motions. However, SLDS does not provide a means to quantify systematic variations in the motion. Previously, Wilson & Bobick presented parametric HMMs [21], an extension to HMMs with which they successfully interpreted human gestures. Inspired by their work, we similarly extend the standard SLDS model to obtain parametric SLDS. We introduce additional global parameters that represent systematic variations in the motion, and present general expectation-maximization (EM) methods for learning and inference. In the learning phase, P-SLDS learns canonical SLDS model from data. In the inference phase, P-SLDS simultaneously quantifies the global parameters and labels the data. We apply these methods to the automatic interpretation of honey-Bee Dances, and present both qualitative and quantitative experimental results on actual Bee-tracks collected from noisy video data. 1
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ICCV - Learning and inference in parametric switching linear dynamic systems
Tenth IEEE International Conference on Computer Vision (ICCV'05) Volume 1, 2005Co-Authors: James M. Rehg, Tucker Balch, Frank DellaertAbstract:We introduce parametric switching linear dynamic systems (P-SLDS) for learning and interpretation of parametrized motion, i.e., motion that exhibits systematic temporal and spatial variations. Our motivating example is the honeyBee dance: Bees communicate the orientation and distance to food sources through the dance angles and waggle lengths of their stylized Dances. Switching linear dynamic systems (SLDS) are a compelling way to model such complex motions. However, SLDS does not provide a means to quantify systematic variations in the motion. Previously, Wilson & Bobick (1999) presented parametric HMMs, an extension to HMMs with which they successfully interpreted human gestures. Inspired by their work, we similarly extend the standard SLDS model to obtain parametric SLDS. We introduce additional global parameters that represent systematic variations in the motion, and present general expectation-maximization (EM) methods for learning and inference. In the learning phase, P-SLDS learns canonical SLDS model from data. In the inference phase, P-SLDS simultaneously quantifies the global parameters and labels the data. We apply these methods to the automatic interpretation of honey-Bee Dances, and present both qualitative and quantitative experimental results on actual Bee-tracks collected from noisy video data
P. Kirk Visscher - One of the best experts on this subject based on the ideXlab platform.
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Adaptation
2013Co-Authors: David A. Tanner, Kirk P. Visscher, P. Kirk VisscherAbstract:Abstract The waggle dance of the honey Bee is used to recruit nest mates to a resource. Dancer Bees, however, may indicate many directions within a single dance bout; we show that this scatter in honey Bee Dances is strongly dependent on the sensory modality used to determine a reference angle in the dance. Dances with a visual reference are more precise than those with a gravity reference. This finding undermines the idea that scatter is introduced into Dances, which the Bees could perform more precisely, in order to spread recruits out over resource patches. It also calls into question reported interspecific differences that had Been interpreted as adaptations of the dance to different habitats. Our results support a non-adaptive hypothesis: that dance scatter results from sensory and performance constraints, rather than modulation of the scatter by the dancing Bee. However, an alternative adaptive hypothesis cannot be ruled out
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Adaptation or constraint? Reference-dependent scatter in honey Bee Dances
Behavioral Ecology and Sociobiology, 2010Co-Authors: David A. Tanner, P. Kirk VisscherAbstract:The waggle dance of the honey Bee is used to recruit nest mates to a resource. Dancer Bees, however, may indicate many directions within a single dance bout; we show that this scatter in honey Bee Dances is strongly dependent on the sensory modality used to determine a reference angle in the dance. Dances with a visual reference are more precise than those with a gravity reference. This finding undermines the idea that scatter is introduced into Dances, which the Bees could perform more precisely, in order to spread recruits out over resource patches. It also calls into question reported interspecific differences that had Been interpreted as adaptations of the dance to different habitats. Our results support a non-adaptive hypothesis: that dance scatter results from sensory and performance constraints, rather than modulation of the scatter by the dancing Bee. However, an alternative adaptive hypothesis cannot be ruled out.