58,565 research outputs found
Intra-dance variation among waggle runs and the design of efficient protocols for honey bee dance decoding
Noise is universal in information transfer. In animal communication, this presents a challenge not only for intended signal receivers, but also to biologists studying the system. In honey bees, a forager communicates to nestmates the location of an important resource via the waggle dance. This vibrational signal is composed of repeating units (waggle runs) that are then averaged by nestmates to derive a single vector. Manual dance decoding is a powerful tool for studying bee foraging ecology, although the process is time-consuming: a forager may repeat the waggle run 1- >100 times within a dance. It is impractical to decode all of these to obtain the vector; however, intra-dance waggle runs vary, so it is important to decode enough to obtain a good average. Here we examine the variation among waggle runs made by foraging bees to devise a method of dance decoding. The first and last waggle runs within a dance are significantly more variable than the middle run. There was no trend in variation for the middle waggle runs. We recommend that any four consecutive waggle runs, not including the first and last runs, may be decoded, and we show that this methodology is suitable by demonstrating the goodness-of-fit between the decoded vectors from our subsamples with the vectors from the entire dances
Object grasping and manipulation in capuchin monkeys (genera Cebus and Sapajus)
The abilities to perform skilled hand movements and to manipulate objects dexterously are landmarks in the evolution of primates. The study of how primates use their hands to grasp and manipulate objects in accordance with their needs sheds light on how these species are physically and mentally equipped to deal with the problems they encounter in their daily life. We report data on capuchin monkeys, highly manipulative platyrrhine species that usually spend a great deal of time in active manipulation to search for food and to prepare it for ingestion. Our aim is to provide an overview of current knowledge on the ability of capuchins to grasp and manipulate objects, with a special focus on how these species express their cognitive potential through manual behaviour. Data on the ability of capuchins to move their hands and on the neural correlates sustaining their actions are reported, as are findings on the manipulative ability of capuchins to anticipate future actions and to relate objects to other objects and substrates.
The manual behaviour of capuchins is considered in different domains, such as motor planning, extractive foraging and tool use, in both captive and natural settings. Anatomofunctional and behavioural similarities to and differences from other haplorrhine species regarding manual dexterity are also discussed
Colour for behavioural success
Colour information not only helps sustain the survival of animal species by guiding sexual selection and foraging behaviour but also is an important factor in the cultural and technological development of our own species. This is illustrated by examples from the visual arts and from state-of-the-art imaging technology, where the strategic use of colour has become a powerful tool for guiding the planning and execution of interventional procedures. The functional role of colour information in terms of its potential benefits to behavioural success across the species is addressed in the introduction here to clarify why colour perception may have evolved to generate behavioural success. It is argued that evolutionary and environmental pressures influence not only colour trait production in the different species but also their ability to process and exploit colour information for goal-specific purposes. We then leap straight to the human primate with insight from current research on the facilitating role of colour cues on performance training with precision technology for image-guided surgical planning and intervention. It is shown that local colour cues in two-dimensional images generated by a surgical fisheye camera help individuals become more precise rapidly across a limited number of trial sets in simulator training for specific manual gestures with a tool. This facilitating effect of a local colour cue on performance evolution in a video-controlled simulator (pick-and-place) task can be explained in terms of colour-based figure-ground segregation facilitating attention to local image parts when more than two layers of subjective surface depth are present, as in all natural and surgical images
Analysis of Dynamic Task Allocation in Multi-Robot Systems
Dynamic task allocation is an essential requirement for multi-robot systems
operating in unknown dynamic environments. It allows robots to change their
behavior in response to environmental changes or actions of other robots in
order to improve overall system performance. Emergent coordination algorithms
for task allocation that use only local sensing and no direct communication
between robots are attractive because they are robust and scalable. However, a
lack of formal analysis tools makes emergent coordination algorithms difficult
to design. In this paper we present a mathematical model of a general dynamic
task allocation mechanism. Robots using this mechanism have to choose between
two types of task, and the goal is to achieve a desired task division in the
absence of explicit communication and global knowledge. Robots estimate the
state of the environment from repeated local observations and decide which task
to choose based on these observations. We model the robots and observations as
stochastic processes and study the dynamics of the collective behavior.
Specifically, we analyze the effect that the number of observations and the
choice of the decision function have on the performance of the system. The
mathematical models are validated in a multi-robot multi-foraging scenario. The
model's predictions agree very closely with experimental results from
sensor-based simulations.Comment: Preprint version of the paper published in International Journal of
Robotics, March 2006, Volume 25, pp. 225-24
Urban Swarms: A new approach for autonomous waste management
Modern cities are growing ecosystems that face new challenges due to the
increasing population demands. One of the many problems they face nowadays is
waste management, which has become a pressing issue requiring new solutions.
Swarm robotics systems have been attracting an increasing amount of attention
in the past years and they are expected to become one of the main driving
factors for innovation in the field of robotics. The research presented in this
paper explores the feasibility of a swarm robotics system in an urban
environment. By using bio-inspired foraging methods such as multi-place
foraging and stigmergy-based navigation, a swarm of robots is able to improve
the efficiency and autonomy of the urban waste management system in a realistic
scenario. To achieve this, a diverse set of simulation experiments was
conducted using real-world GIS data and implementing different garbage
collection scenarios driven by robot swarms. Results presented in this research
show that the proposed system outperforms current approaches. Moreover, results
not only show the efficiency of our solution, but also give insights about how
to design and customize these systems.Comment: Manuscript accepted for publication in IEEE ICRA 201
Taking movement data to new depths : Inferring prey availability and patch profitability from seabird foraging behavior
Funded byNatural Environment Research Council. Grant Number: NE/K007440/1 and Marine Scotland Science and Seabird Tracking and Research (STAR) Project led by the Royal Society for the Protection of Birds (RSPB)Peer reviewedPublisher PD
Modelling foraging movements of diving predators : A theoretical study exploring the effect of heterogeneous landscapes on foraging efficiency
Peer reviewedPublisher PD
Composite random search strategies based on non-directional sensory cues
Many foraging animals find food using composite random search strategies,
which consist of intensive and extensive search modes. Models of composite
search can generate predictions about how optimal foragers should behave in
each search mode, and how they should determine when to switch between search
modes. Most of these models assume that foragers use resource encounters to
decide when to switch between search modes. Empirical observations indicate
that a variety of organisms use non-directional sensory cues to identify areas
that warrant intensive search. These cues are not precise enough to allow a
forager to directly orient itself to a resource, but can be used as a criterion
to determine the appropriate search mode. As a potential example, a forager
might use olfactory information, which could help it determine if an area is
worth searching carefully. We developed a model of composite search based on
non-directional sensory cues. With simulations, we compared the search
efficiencies of composite foragers that use resource encounters as their
mode-switching criterion with those that use non-directional sensory cues. We
identified optimal search patterns and mode-switching criteria on a variety of
resource distributions, characterized by different levels of resource
aggregation and density. On all resource distributions, foraging strategies
based on the non-directional sensory criterion were more efficient than those
based on the resource encounter criterion. Strategies based on the
non-directional sensory criterion were also more robust to changes in resource
distribution. Our results suggest that current assumptions about the role of
resource encounters in models of optimal composite search should be
re-examined. The search strategies predicted by our model can help bridge the
gap between random search theory and traditional patch-use foraging theory
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