Behavioral Diversity Research Articles

Equilibrium and kinetics of sorption and resorption of acid and basic dyes using the pulp of carob pods

Being an abundant product in Algeria, pulp of carob pods (PCP) was used in this study as a biosorbent for Methylene blue (MB) and Congo red (CR) removal from aqueous media in batch mode in two successive steps. Once the first dye is adsorbed, the biosorbent is used as is to adsorb the second dye in order to study the interactions between them. Characterization of PCP by FTIR spectroscopy, Scanning Electron Microscopy (SEM), EDX, and point of zero charge showed that the principal functional groups present at the surface are oxygenated with a pHpzc value of the 7.2. Contact time of 60 min was amply sufficient to reach equilibrium for both dyes onto PCP and recuperated biosorbents. pH effect on the biosorption onto PCP shows a behavioral divergence between both dyes. Maximum biosorption uptake of CR was observed at pH value of 6.38 while pH variation has no remarkable influence on MB biosorption and the initial pH solution of 5.75 was taken for subsequent biosorption experiments. The adsorption isotherms obtained are in good agreement with the models of Langmuir and Freundlich and the kinetics are well described by the pseudo-second-order model.

Small mammal personalities generate context dependence in the seed dispersal mutualism

Mutualisms are foundational components of ecosystems with the capacity to generate biodiversity through adaptation and coevolution and give rise to essential services such as pollination and seed dispersal. To understand how mutualistic interactions shape communities and ecosystems, we must identify the mechanisms that underlie their functioning. One mechanism that may drive mutualisms to vary in space and time is the unique behavioral types, or personalities, of the individuals involved. Here, our goal was to examine interindividual variation in the seed dispersal mutualism and identify the role that different personalities play. In a field experiment, we observed individual deer mice (Peromyscus maniculatus) with known personality traits predating and dispersing seeds in a natural environment and classified all observed interactions made by individuals as either positive or negative. We then scored mice on a continuum from antagonistic to mutualistic and found that within a population of scatter hoarders, some individuals are more mutualistic than others and that one factor driving this distinction is animal personality. Through this empirical work, we provide a conceptual advancement to the study of mutualism by integrating it with the study of intraspecific behavioral variation. These findings indicate that animal personality is a previously overlooked mechanism generating context dependence in plant–animal interactions and suggest that behavioral diversity may have important consequences for the functioning of mutualisms.

Behavioral Diversity Generated From Body–Environment Interactions in a Simulated Tensegrity Robot

Behavioral Diversity Generated From Body–Environment Interactions in a Simulated Tensegrity Robot

Importance of substrate on welfare in swimming crab (Portunus trituberculatus) culture: A territorial behavior perspective

Concern for animal welfare in aquaculture is increasing. Environmental enrichment (EE) is an effective means to improve the welfare of animals, which is linked to their behavior. Territorial behavior includes interactions between animals and their environment and conspecifics, and can directly reflect the welfare status of cultured animals. To explore the influence of different substate, an important influence factor of EE, on welfare of swimming crab (Portunus trituberculatus), a behavior acquisition system was established. Moving trajectory, territory size, time budgeting, total number of territorial behaviors, and bouts of crabs in EE groups (sand substrate, sand and shell mixed substrate, and shell substate) and the control (hard bottom) group were calculated and analyzed. Furthermore, the territorial behavior score of crabs was calculated using PCA to estimate territoriality. According to the results, the presence of substrate EE effectively reduced the territoriality of the swimming crabs, and sand as substrate affected most significantly. In the control group, stereotypical behaviors of crabs (repeated movements for long periods) indicated a low welfare level. In the EE group, interactions with the substrate, including burying behavior, digging, etc., revealed a higher behavioral diversity, which demonstrated that a suitable EE could effectively improve the welfare of swimming crabs. In general, from the perspective of territorial behavior, the presence of substrate, especially sand, was an effective means of improving the welfare of cultured swimming crabs.

Stochastic Steady-State Security Assessment for Power System Operation by Chance Constrained Optimal Power Flow-Based Load Shedding

The operational uncertainty of the power system is significantly increased by the high penetration of renewable energy and diversification of load behavior, which have aroused the novel research on stochastic steady-state security assessment (SSSA) urgently when the operational condition gets worse and contingency happens more frequently. First of all, a novel contingency analysis model has been proposed based on chance constrained optimal power flow (CCOPF) in this work, which is able to give a comprehensive consideration on conventional generator outage, uncertainty of system operation and load shedding of interruptible loads (ILs). Moreover, the proposed model is very practical and can be solved much efficiently by an iteration method so that the purpose of secure system operation after contingency can be better realized. Second, to further enhance the steady-state security of the system, a novel pricing method for ILs has been developed here. In addition, a composite contingency ranking index has been also established to reflect the severity of generator outage more accurately. Finally, extensive study results based on a modified IEEE-39 test system have demonstrated the validity of the proposed model, which can hold a good balance amongst security, economy, controllability, and maneuverability.

Consequences of coupled barriers to gene flow for the build-up of genomic differentiation.

Theory predicts that when different barriers to gene flow become coincident, their joint effects enhance reproductive isolation and genomic divergence beyond their individual effects, but empirical tests of this "coupling" hypothesis are rare. Here, we analyze patterns of gene exchange among populations of European corn borer moths that vary in the number of acting barriers, allowing for comparisons of genomic variation when barrier traits or loci are in coincident or independent states. We find that divergence is mainly restricted to barrier loci when populations differ by a single barrier, whereas the coincidence of temporal and behavioral barriers is associated with divergence of two chromosomes harboring barrier loci. Furthermore, differentiation at temporal barrier loci increases in the presence of behavioral divergence and differentiation at behavioral barrier loci increases in the presence of temporal divergence. Our results demonstrate how the joint action of coincident barrier effects leads to levels of genomic differentiation that far exceed those of single barriers acting alone, consistent with theory arguing that coupling allows indirect selection to combine with direct selection and thereby lead to a stronger overall barrier to gene flow. Thus, the state of barriers-independent or coupled-strongly influences the accumulation of genomic differentiation.

Quantifying the effects of environment and population diversity in multi-agent reinforcement learning

Generalization is a major challenge for multi-agent reinforcement learning. How well does an agent perform when placed in novel environments and in interactions with new co-players? In this paper, we investigate and quantify the relationship between generalization and diversity in the multi-agent domain. Across the range of multi-agent environments considered here, procedurally generating training levels significantly improves agent performance on held-out levels. However, agent performance on the specific levels used in training sometimes declines as a result. To better understand the effects of co-player variation, our experiments introduce a new environment-agnostic measure of behavioral diversity. Results demonstrate that population size and intrinsic motivation are both effective methods of generating greater population diversity. In turn, training with a diverse set of co-players strengthens agent performance in some (but not all) cases.

Particle Morphology of Medusavirus Inside and Outside the Cells Reveals a New Maturation Process of Giant Viruses.

ABSTRACTMedusavirus, a giant virus, is phylogenetically closer to eukaryotes than the other giant viruses and has been recently classified as an independent species. However, details of its morphology and maturation process in host cells remain unclear. Here, we investigated the particle morphology of medusavirus inside and outside infected cells using conventional transmission electron microscopy (C-TEM) and cryo-electron microscopy (cryo-EM). The C-TEM of amoebae infected with the medusavirus showed four types of particles, i.e., pseudo-DNA-empty (p-Empty), DNA-empty (Empty), semi-DNA-full (s-Full), and DNA-full (Full). Time-dependent changes in the four types of particles and their intracellular localization suggested a new maturation process for the medusavirus. Viral capsids and viral DNAs are produced independently in the cytoplasm and nucleus, respectively, and only the empty particles located near the host nucleus can incorporate the viral DNA into the capsid. Therefore, all four types of particles were found outside the cells. The cryo-EM of these particles showed that the intact virus structure, covered with three different types of spikes, was preserved among all particle types, although with minor size-related differences. The internal membrane exhibited a structural array similar to that of the capsid, interacted closely with the capsid, and displayed open membrane structures in the Empty and p-Empty particles. The results suggest that these open structures in the internal membrane are used for an exchange of scaffold proteins and viral DNA during the maturation process. This new model of the maturation process of medusavirus provides insight into the structural and behavioral diversity of giant viruses.IMPORTANCE Giant viruses exhibit diverse morphologies and maturation processes. In this study, medusavirus showed four types of particle morphologies, both inside and outside the infected cells, when propagated in amoeba culture. Time-course analysis and intracellular localization of the medusavirus in the infected cells suggested a new maturation process via the four types of particles. Like the previously reported pandoravirus, the viral DNA of medusavirus is replicated in the host’s nucleus. However, viral capsids are produced independently in the host cytoplasm, and only empty capsids near the nucleus can take up viral DNA. As a result, many immature particles were released from the host cell along with the mature particles. The capsid structure is well conserved among the four types of particles, except for the open membrane structures in the empty particles, suggesting that they are used to exchange scaffold proteins for viral DNAs. These findings indicate that medusavirus has a unique maturation process.

Morphological Sensitivity and Falling Behavior of Paper V-Shapes.

Behavioral diversity seen in biological systems is, at the most basic level, driven by interactions between physical materials and their environment. In this context we are interested in falling paper systems, specifically the V-shaped falling paper (VSFP) system that exhibits a set of discrete falling behaviors across the morphological parameter space. Our previous work has investigated how morphology influences dominant falling behaviors in the VSFP system. In this article we build on this analysis to investigate the nature of behavioral transitions in the same system. First, we investigate stochastic behavior transitions. We demonstrate how morphology influences the likelihood of different transitions, with certain morphologies leading to a wide range of possible paths through the behavior-space. Second, we investigate deterministic transitions. To investigate behaviors over longer time periods than available in falling experiments we introduce a new experimental platform. We demonstrate how we can induce behavior transitions by modulating the energy input to the system. Certain behavior transitions are found to be irreversible, exhibiting a form of hysteresis, while others are fully reversible. Certain morphologies are shown to behave like simplistic sequential logic circuits, indicating that the system has a form of memory encoded into the morphology-environment interactions. Investigating the limits of how morphology-environment interactions induce non-trivial behaviors is a key step for the design of embodied artificial life-forms.

Geography and social network influence on crowdfunding a French microbrewery

AbstractThe objective of this article is to explore the influence of home bias and the moderating role of social networks (and more particularly family and friends—F&F) in the crowdfunding of a microbrewery in a French region (a lucrative business that uses a territorial solidarity process). We have chosen the case study as methodology to show that neither home bias nor F&F have a significant influence on amounts paid by individuals in crowdfunding. The results are specific to the case studied and are comparable to those of social enterprise. They explain but also justify the behavioural diversity crowdfunding can induce.

Evidence for basic units of upper limb muscle synergies underlying a variety of complex human manipulations.

Manipulations require complex upper limb movements in which the central nervous system (CNS) must deal with many degrees of freedom. Evidence suggests that the CNS utilizes motor primitives called muscle synergies to simplify the production of movements. However, the exact neural mechanism underlying muscle synergies to control a wide array of manipulations is not fully understood. Here, we tested whether there are basic units of muscle synergies that can explain a diverse range of manipulations. We measured the electromyographic activities of 20 muscles across the shoulder, elbow, and wrist and fingers during 24 manipulation tasks. As a result, nonnegative matrix factorization identified nine basic units of muscle synergies derived from the upper limb muscles that are shared across all tasks. The high similarity between muscle synergies of each of the 24 tasks and various combinations of nine basic unit muscle synergies in a single and/or merging state provides evidence that the CNS flexibly selects and modifies the degree of contribution of the nine basic units of muscle synergies to overcome different mechanical demands of tasks.NEW & NOTEWORTHY We expanded upon experiments that investigated motor modularity in upper limb movements in humans. The identification of modular features, including distinct functional muscle weightings, during highly variable manipulation tasks supports a hypothetical neural mechanism in which the CNS combines preexisting basic patterns of muscle synergies rather than framing new patterns to deal with behavioral diversity in the upper limb.

Representing and Analyzing the Dynamics of an Agent-Based Adaptive Social Network Model with Partial Integro-Differential Equations

We formulated and analyzed a set of partial integro-differential equations that capture the dynamics of our adaptive network model of social fragmentation involving behavioral diversity of agents. Previous results showed that, if the agents’ cultural tolerance levels were diversified, the social network could remain connected while maintaining cultural diversity. Here we converted the original agent-based model into a continuous equation-based one so we can gain more theoretical insight into the model dynamics. We restricted the node states to 1-D continuous values and assumed the network size was very large. As a result, we represented the whole system as a set of partial integro-differential equations about two continuous functions: population density and connection density. These functions are defined over both the state and the cultural tolerance of nodes. We conducted numerical integration of the developed equations using a custom-made integrator implemented in Julia. The results obtained were consistent with the simulations of the original agent-based adaptive social network model we previously reported, confirming the robustness of the original finding. Specifically, when the variance of cultural tolerance d is large enough, the population with low d maintains the original clusters of cultures/opinions, while the one with high d tends to come to the center and connect culturally distant groups. Parameter dependence of the model behavior was also revealed through systematic numerical experiments.

Environmental influences on human innovation and behavioural diversity in southern Africa 92-80 thousand years ago.

Africa's Middle Stone Age preserves sporadic evidence for novel behaviours among early modern humans, prompting a range of questions about the influence of social and environmental factors on patterns of human behavioural evolution. Here we document a suite of novel adaptations dating approximately 92-80 thousand years before the present at the archaeological site Varsche Rivier 003 (VR003), located in southern Africa's arid Succulent Karoo biome. Distinctive innovations include the production of ostrich eggshell artefacts, long-distance transportation of marine molluscs and systematic use of heat shatter in stone tool production, none of which occur in coeval assemblages at sites in more humid, well-studied regions immediately to the south. The appearance of these novelties at VR003 corresponds with a period of reduced regional wind strength and enhanced summer rainfall, and all of them disappear with increasing winter rainfall dominance after 80 thousand years before the present, following which a pattern of technological similarity emerges at sites throughout the broader region. The results indicate complex and environmentally contingent processes of innovation and cultural transmission in southern Africa during the Middle Stone Age.

Divergence in Heliconius flight behaviour is associated with local adaptation to different forest structures.

Microhabitat choice plays a major role in shaping local patterns of biodiversity. In butterflies, stratification in flight height has an important role in maintaining community diversity. Despite its presumed importance, the role of behavioural shifts in early stages of speciation in response to differences in habitat structure is yet to be established. Here, we investigated variation in flight height behaviour in two closely related Heliconius species, H. erato cyrbia and H. himera, which produce viable hybrids but are isolated across an environmental gradient, spanning lowland wet forest to high-altitude scrub forest. Speciation in this pair is associated with strong assortative mating, but ecological isolation and local adaptation are also considered essential for complete reproductive isolation. We quantified differences in flight height and forest structure across the environmental gradient and tested the importance of resource distribution in explaining flight behaviour. We then used common garden experiments to test whether differences in flight height reflect individual responses to resource distribution or genetically determined shifts in foraging behaviour. We found that the two species fly at different heights in the wild, and demonstrated that this can be explained by differences in the vertical distribution of plant resources. In both the wild and captivity, H. himera choose to fly lower and feed at lower positions, closely mirroring differences in resource availability in the wild. Given expectations that foraging efficiency contributes to survival and reproductive success, we suggest that foraging behaviour may reflect local adaptation to divergent forest structures. Our results highlight the potential role of habitat-dependent divergence in behaviour during the early stages of speciation.

Digging ability and digging performance in a hyporheic gravel-dwelling crayfish, the hairy crayfish Cambarus friaufi (Hobbs 1953) (Decapoda: Astacidae: Cambaridae)

Abstract Crayfishes are known for their ability to construct burrows, although there is intra- and interspecific variation in the complexity and reliance on such burrows. Crayfishes historically have been classified into ecological groupings based on their reliance on their burrow and the burrows connection to the water table. These ecological classifications, however, do not completely account for the behavioral diversity throughout crayfishes. One group of crayfishes that do not necessarily fit into these ecological classifications are members of the invalid subgenus Glareocola of Cambarus Erichson, 1846, which includes four species: C. brachydactylus (Hobbs, 1953), C. friaufi (Hobbs, 1953), C. polypilosus (Loughman & Williams, 2018), and C. williami (Bouchard & Bouchard 1995). All four species inhabit streams characterized by loose chert gravel, which creates ample interstitial spaces and potential access to the streambed’s hyporheic zone. We studied how one member of the Glareocola group, C. friaufi, exhibits unique morphological and behavioral adaptations that enable individuals to dig into the hyporheic zone of their natural chert substrate. We found that C. friaufi was sexually monomorphic regarding the relationship between body size and claw size, which contrasts findings from other stream-dwelling crayfish species. By evaluating the digging ability and digging performance of C. friaufi and sand, pea gravel, and their natural chert substrate, we also demonstrate how their digging ability is highly adapted to their natural chert substrate. Individuals of C. friaufi were either unable to dig or rarely dig underneath substrates other than chert. We discuss our results considering the behavioral ecology and natural history of the crayfishes within this enigmatic group.

Disentangling tourism impacts on small-scale fishing pressure

Tourism and small-scale fisheries are two of the most important economic sectors in coastal areas around the world, yet the impact of tourism development on fisheries is understudied within the SSF literature. Studies have documented various aspects of tourism-fishery interactions, but it is not clear how they combine to impact total fishing pressure. The addition of alternative livelihoods is widely expected to alleviate pressure on fisheries resources, yet rural development transitions often accelerate exploitation of natural resources. This paper analyzes how tourism development impacts community-level fishing pressure through a comparative case study of fishing behavior and livelihood engagement in seven neighboring fishing communities in the Colombian Pacific, using space-for-time substitution to estimate change over time. Findings indicate that while tourism development leads to a decline in fishery participation, this decline can be more than offset by increases in fishing effort and improvements in fishing methods. This is related to an overall pattern of livelihood specialization and intensification that results in a divergence of household-level fishing behavior – between those that exit the fishery and those that fish more intensively – and an increase in community-wide fishing pressure. However, impacts vary from place to place due to contextual factors in the biophysical environment and socio-political systems that shape how tourism development affects fishing behavior and whether or not it is likely to benefit sustainable small-scale fisheries. These findings can be used to support place-based assessments in order to anticipate impacts, proactively design fisheries management, and inform more sustainable tourism development planning.

Distinguishing mobility and immobility when establishing species-specific activity budgets: A case study with gorillas (Gorilla berengei berengei and Gorilla gorilla gorilla).

Activity budgets characterize the distribution of behavior over a specified time period. In some cases, having comparable data from free-ranging populations can help inform the management of wildlife in zoos and sanctuaries. For example, although variations exist across subspecies, seasons, and study sites, diurnal activity budgets for free-ranging gorillas largely consist of feeding and resting. Unfortunately, most studies do not consistently differentiate between the type of activities gorillas exhibit while locomoting versus stationary. Therefore, it can be difficult to characterize optimal levels of aerobic activity that might enhance body condition or promote gorilla health in zoos and sanctuaries. In this study, we concurrently measured the mobility state and activity of mountain gorillas (Gorilla beringei beringei) in Volcanoes National Park, Rwanda. From June to August 2015, behavioral data were collected using group scan sampling with 15-min intervals in two groups (N = 29 gorillas) monitored by the Dian Fossey Gorilla Fund International. Overall, gorillas spent significantly more time immobile (85.2% of observations) than mobile(14.8%), revealing energy expenditure levels comparable to western lowland gorillas living in zoos. There was no difference in behavioral diversity when gorillas were mobile versus immobile but adult females exhibited substantially less behavioral diversity while immobile than other age-sex classes. There was more diversity in behaviors following the transition from immobile to mobile than vice versa, particularly for adult females. Future studies should concurrently measure mobility state and behavior to improve the precision of activity budget data and serve as a more useful tool for evaluating optimal activity levels for wildlife in human care.

Technological diversity in the Late Pleistocene of the Nyanza Rift, Kenya: Archaeological excavations at Kapsarok 1 and Anderea’s Farm 1

The archaeological record of Late Pleistocene Africa is characterized by behavioral diversity and change, notably the technological shift from the Middle Stone Age (MSA) to Later Stone Age (LSA). Recent research shows the MSA-LSA transition was a spatially and temporally complex process. Understanding this transition requires a composite record of archaeological sites from precise chronological and stratigraphic contexts within multiple regions. Here we present excavation and analysis of two open-air Late Pleistocene sites in chronological and geographic association: Anderea’s Farm 1 (GrJe-8) and Kapsarok 1 (GrJe-9), from the Nyanza Rift, Kenya. Volcanic ash correlations of artifact-bearing sediments provide ages of ∼ 45–36 ka for Anderea’s Farm 1 (GrJe-8) and ∼ 50 ka for Kapsarok 1 (GrJe-9). Locally procured lavas were used to produce different stone tools by disparate technological methods. Lithic production at Anderea’s Farm 1 focused on the manufacture of short irregular flakes using expedient and discoidal methods, and tools are dominated by heavy-duty types. In contrast, Kapsarok 1 is characterized by elongated and convergent blanks produced using hierarchical core technologies. Viewed together, Kapsarok 1 and Anderea’s Farm 1 emphasizes high diversity in Late Pleistocene technology of the Victoria Basin. We argue these different technologies are most parsimoniously interpreted as expressions of a broad and flexible behavioral repertoire. Further, our results emphasize how excavation and analysis of open-air archaeological sites in secure chronological and stratigraphic contexts provides the means to sample the necessary range of human behaviours across a landscape commensurate with past forager geographic ranges.

Otolith Microchemistry and Demographic History Provide New Insight into the Migratory Behavior and Heterogeneous Genetic Divergence of Coilia grayii in the Pearl River

Coilia grayii is the anadromous form of anchovy that is distributed in the East and South China Seas. It is a common fish species in the estuarine area of the Pearl River. Nevertheless, freshwater populations appear upstream in the Pearl River, but the migratory pathway has been mostly impeded by dam construction. Behavioral differences and constrained habitat within tributaries are suspected of promoting genetic divergence in these populations. In this study, we investigated the migratory behavior and genetic divergence of six populations of C. grayii fragmented by dams based on the otolith strontium/calcium (Sr/Ca) ratio, mitochondrial DNA, and microsatellite genotyping. All populations were in freshwater with low Sr/Ca ratios, except the estuarine population (Humen population) hatched in brackish water. Reduced nucleotide diversity corresponding to distance was observed. Populations from distant hydrological regions exhibited a decline in genetic diversity and a significant difference with the remaining populations after fitting the isolation by distance model. Pairwise fixation indices confirmed these results and moderate and significant differentiation was found between Hengxian site and downstream sites. Furthermore, STRUCTURE analyses revealed that all separated populations exhibited an admixed phylogenetic pattern except for individuals from the Hengxian locality. The upstream sites showed significantly increased resistance to gene flow from the estuarine population because of isolation by the dam. The results of the neutrality test and Bayesian skyline plots demonstrated complex demography—individuals’ experienced historical expansion and partial upper-dam populations had recently undergone a colonization, forming a new genetic structure. Accordingly, this study demonstrates differences in the migration pattern and genetic differentiation of C. grayii as a consequence of demographic history and current processes (habitat fragmentation and colonization).

Flexibility and rigidity in hunting behaviour in rodents: is there room for cognition?

Predatory hunting is a complex species-typical behaviour involving different skills, some of which may include learning. This research aims to distinguish between rigid and flexible parts in live-insect hunting behaviour in nine herbivorous and granivorous rodent species, and to find out whether there is room for cognition in this activity. In laboratory experiments, all species studied manifest skilful attacks towards insects in a manner that is typical for specialised predators chasing a fleeing prey. Voles demonstrate a "core" and somewhat primitive scheme of a hunting pattern: approaching a potential victim, biting it, and then seizing and handling. Hamsters display the tendency to start their attacks by actions with paws, but they can achieve success only using teeth as well. Gerbils can successfully use both paws and teeth to start the attack, which brings their hunting behaviour closer to that of specialised rodent predators. We revealed variability in the display of hunting in different species, methods of seizing the prey, and the number of attempts to attack an insect before catching it. We found specific flexible fragments within the "bite-grasp-handle" bouts that can be precursors for adaptive phenotypic variations and include some cognitive attributes. We hypothesise that the divergence and specialisation of predatory behaviour in rodents can be based on the natural fragmentation of the original hunting patterns, that is, on the loss or recombination of particular behavioural elements. We consider a possible link between the fragmentation of hunting behaviour and social learning in different classes of animals and conjecture an intriguing correlation between predatory activity, cognitive skills and personal traits in rodents.