Tuna Swarm Optimization: A Novel Swarm-Based Metaheuristic Algorithm for Global Optimization

In this paper, a novel swarm-based metaheuristic algorithm is proposed, which is called tuna swarm optimization (TSO). The main inspiration for TSO is based on the cooperative foraging behavior of tuna swarm. The work mimics two foraging behaviors of tuna swarm, including spiral foraging and parabolic foraging, for developing an effective metaheuristic algorithm. The performance of TSO is evaluated by comparison with other metaheuristics on a set of benchmark functions and several real engineering problems. Sensitivity, scalability, robustness, and convergence analyses were used and combined with the Wilcoxon rank-sum test and Friedman test. The simulation results show that TSO performs better compared to other comparative algorithms.

The Pleistocene Social Contract

No human now gathers for himself or herself the essential resources for life: food, shelter, clothing and the like. Humans are obligate co-operators, and this has been true for tens of thousands of years; probably much longer. In this regard, humans are very unusual. In the living world more generally, cooperation outside the family is rare. Though it can be very profitable, it is also very risky, as cooperation makes an agent vulnerable to incompetence and cheating. This book presents a new picture of the emergence of cooperation in our lineage, developing through four fairly distinct phases. Our trajectory began from a baseline that was probably fairly similar to living great apes, who cooperate, but in fairly minimal ways. As adults, they rarely depend on others when the outcome really matters. This book suggests that cooperation began to be more important for humans through an initial phase of cooperative foraging generating immediate returns from collective action in small mobile bands. This established in our lineage about 1.8 million years ago, perhaps earlier. Over the rest of the Pleistocene, cooperation became more extended in its social scale, with forms of cooperation between bands gradually establishing, and in spatial and temporal scale too, with various forms of reciprocation becoming important. The final phase was the emergence of cooperation in large scale, hierarchical societies in the Holocene, beginning about 12,000 years ago. This picture is nested in a reading of the archaeological and ethnographic record, and twinned to an account of the gradual elaboration of cultural learning in our lineage, making cooperation both more profitable and more stable.

Effects of Group Behavior in The Predatory Raid on Damselfish Nests By The False Cleanerfish Aspidontus Taeniatus

The benefits of group behavior have been reported in a variety of animals. The false cleanerfish Aspidontus taeniatus, which resembles the bluestreak cleaner wrasse Labroides dimidiatus, is the best-known example of mimicry in vertebrates. This mimicry system has been viewed as an aggressive mimicry to bite fish fins. However, recent field studies have reported that large individuals of the false cleanerfish form groups and jointly raid fish nests to eat eggs that are guarded by their parents. Since the cleaner wrasse does not form such groups or specialize in egg-eating, the feeding groups of the false cleanerfish is assumed to reduce the effectiveness of mimicry. Here, we conducted field observations to clarify the functions of group behavior in egg-eating in the false cleanerfish. The false cleanerfish formed groups of 2–12 individuals when they raided breeding nests of 13 damselfish (Pomacentridae) and one triggerfish (Balistidae). The results showed that the group behavior has two effects: a dilution effect, which reduces the risk of being attacked by egg-guarding fish, and an increase in foraging efficiency. We conclude that the false cleanerfish need to form cooperative foraging groups during egg-eating because the egg-guarding parents could see through the mimicry.

Deep-diving beaked whales dive together but forage apart

Echolocating animals that forage in social groups can potentially benefit from eavesdropping on other group members, cooperative foraging or social defence, but may also face problems of acoustic interference and intra-group competition for prey. Here, we investigate these potential trade-offs of sociality for extreme deep-diving Blainville′s and Cuvier's beaked whales. These species perform highly synchronous group dives as a presumed predator-avoidance behaviour, but the benefits and costs of this on foraging have not been investigated. We show that group members could hear their companions for a median of at least 91% of the vocal foraging phase of their dives. This enables whales to coordinate their mean travel direction despite differing individual headings as they pursue prey on a minute-by-minute basis. While beaked whales coordinate their echolocation-based foraging periods tightly, individual click and buzz rates are both independent of the number of whales in the group. Thus, their foraging performance is not affected by intra-group competition or interference from group members, and they do not seem to capitalize directly on eavesdropping on the echoes produced by the echolocation clicks of their companions. We conclude that the close diving and vocal synchronization of beaked whale groups that quantitatively reduces predation risk has little impact on foraging performance.

Evolving resolve

The broad spectrum revolution brought greater dependence on skill and knowledge, and more demanding, often social, choices. We adopt Sterelny's account of how cooperative foraging paid the costs associated with longer dependency, and transformed the problem of skill learning. Scaffolded learning can facilitate cognitive control including suppression, whereas scaffolded exchange and trade, including inter-temporal exchange, can help develop resolve.

Evolving Resolve

The broad spectrum revolution brought greater dependence on skill and knowledge, and more demanding, often social, choices. We adopt Sterelny's account of how cooperative foraging paid the costs associated with longer dependency, and transformed the problem of skill learning. Scaffolded learning can facilitate cognitive control including suppression, while scaffolded exchange and trade, including intertemporal exchange, can help develop resolve.

Foraging and avoiding predators

The chapter considers the generalist and specialist diets of birds, and the behaviours and adaptations used by birds to find food. Special attention is given to the threat to birds from plastics pollution and the impact of plastic ingestion. Cooperative foraging and cooperative hunting are discussed as are the behaviours adopted by birds that do not cooperate or share. Feeding behaviour is considered in light of the theory of optimal foraging, particularly in relation to prey choice and to the balancing of risk. The impact of urban living upon the diets and foraging behaviours of birds is discussed. A broad range of predator avoidance behaviours are described and evaluated.

Cooperative foraging during larval stage affects fitness in Drosophila

SummaryCooperative behavior can confer advantages to animals. This is especially true for cooperative foraging which provides fitness benefits through more efficient acquisition and consumption of food. While examples of group foraging have been widely described, the principles governing formation of such aggregations and rules that determine group membership remain poorly understood. Here we take advantage of an experimental model system featuring cooperative foraging behavior in Drosophila. Under crowded conditions, fly larvae form coordinated digging groups (clusters), where individuals are linked together by sensory cues and group membership requires prior experience. However, fitness benefits of Drosophila larval clustering remain unknown. We demonstrate that animals raised in crowded conditions on food partially processed by other larvae experience a developmental delay presumably due to the decreased nutritional value of the substrate. Intriguingly, same conditions promote formation of cooperative foraging clusters which further extends larval stage compared to non-clustering animals. Remarkably, this developmental retardation also results in a relative increase in wing size, serving an indicator of adult fitness. Thus, we find that the clustering-induced developmental delay is accompanied by fitness benefits. Therefore, cooperative foraging, while delaying development, may have evolved to give Drosophila larvae benefits when presented with competition for limited food resources.