Cooperative Foraging Research Articles

Learning to walk in the forest

AbstractThis paper examines how BaYaka children from the Congo Basin learn to “walk in the forest” (botamboli na ndima). Specifically, after placing forest walking within historical and ethnographic context, we consider how this practice contributes to BaYaka motor, cognitive, and social development, and thus, to the acquisition of culture. To do so, we draw from our own observations and those of other researchers working throughout the region. We outline four ways in which “walking in the forest” is directly and indirectly socialized: through motion‐full caregiving in infancy, play and cooperative foraging in early and middle childhood, and exploration in adolescence. Taking “walking in the forest” as a focal point, we argue that the specific ways in which caregivers enhance learning are grounded in BaYaka subsistence and forest management practices, and that learning to walk in the forest is central to the maintenance of BaYaka social networks and the flow of knowledge in the Congo Basin.

Population parameters of Drosophila larval cooperative foraging.

Cooperative foraging behavior can be advantageous when there is a common exploitable resource. By cooperating, members of the group can take advantage of the potential of increased efficiency of working together as well as equitable distribution of the product. An experimental signature of cooperative foraging is an Allee effect where at a certain number of individuals, there is a peak of fitness. What happens when there are intruders especially ones that do not contribute to any work required for foraging? Drosophila larvae secrete digestive enzymes and exodigest food. Under crowded conditions in liquid food these larvae form synchronized feeding clusters which provides a fitness benefit. A key for this synchronized feeding behavior is the visually guided alignment between adjacent larvae in a feeding cluster. Larvae who do not align their movements are excluded from the groups and subsequently lose the benefit. This may be a way of editing the group to include only known members. To test the model, the fitness benefit from cooperative behavior was further investigated to establish an Allee effect for a number of strains including those who cannot exodigest or cluster. In a standard lab vial, about 40 larvae is the optimal number for fitness. Combinations of these larvae were also examined. The expectation was that larvae who do not contribute to exodigestion are obligate cheaters and would be expelled. Indeed, obligate cheaters gain greatly from the hosts but paradoxically, so do the hosts. Clusters that include cheaters are more stable. Therefore, clustering and the benefits from it are dependent on more than just the contribution to exodigestion. This experimental system should provide a rich future model to understand the metrics of cooperative behavior.

Communal cooperative aquatic foraging by Wandering Whistling-Ducks Dendrocygna arcuata

Communal cooperative foraging from the surface of water is here reported for the first time in the Wandering Whistling-Duck Dendrocygna arcuata. Five adult Wandering Whistling-Ducks were observed to form a circle of outwardly facingnindividuals, using their legs and feet to churn the water beneath them and then to duck-dive into the disturbed water within the circle to forage. Such a specific cooperative foraging technique does not appear to have been previously documented in this or any other species of waterfowl.

Harbor Porpoise Aggregations in the Salish Sea

Harbor porpoises are typically seen in small groups of 1–3 individuals, with aggregations of 20+ individuals treated as rare events. Since the 1990s, the harbor porpoise population in the Salish Sea has seen a significant recovery, and an increased number of observed aggregations that exceed the more usual small group sizes has been observed in recent years. By combining the observational data of United States and Canadian research organizations, community scientists, and whale watch captains or naturalists, we demonstrate that harbor porpoise aggregations appear to be more common than previously known, with 160 aggregations documented in 2022 alone. Behavioral data also indicate that foraging behaviors are common and social behaviors, like mating, are seen more often during these encounters compared to small groups. Other behaviors that are considered to be rare or unknown were also observed during these encounters, including cooperative foraging and vessel approach. These aggregations are likely important foraging and social gatherings for harbor porpoises. This holistic approach integrating data from two countries and multiple sources provides a population level assessment that more effectively reflects the behavior of harbor porpoises in this region, which do not recognize the socio-political boundaries imposed upon the natural world.

Foraging synchrony drives resilience in human–dolphin mutualism

Interactions between humans and nature have profound consequences, which rarely are mutually beneficial. Further, behavioral and environmental changes can turn human-wildlife cooperative interactions into conflicts, threatening their continued existence. By tracking fine-scale behavioral interactions between artisanal fishers and wild dolphins targeting migratory mullets, we reveal that foraging synchrony is key to benefiting both predators. Dolphins herd mullet schools toward the coast, increasing prey availability within the reach of the net-casting fishers, who gain higher foraging success-but only when matching the casting behavior with the dolphins' foraging cues. In turn, when dolphins approach the fishers' nets closely and cue fishers in, they dive for longer and modify their active foraging echolocation to match the time it takes for nets to sink and close over mullets-but only when fishers respond to their foraging cues appropriately. Using long-term demographic surveys, we show that cooperative foraging generates socioeconomic benefits for net-casting fishers and ca. 13% survival benefits for cooperative dolphins by minimizing spatial overlap with bycatch-prone fisheries. However, recent declines in mullet availability are threatening these short- and long-term benefits by reducing the foraging success of net-casting fishers and increasing the exposure of dolphins to bycatch in the alternative fisheries. Using a numerical model parametrized with our empirical data, we predict that environmental and behavioral changes are pushing this traditional human-dolphin cooperation toward extinction. We propose two possible conservation actions targeting fishers' behavior that could prevent the erosion of this century-old fishery, thereby safeguarding one of the last remaining cases of human-wildlife cooperation.

Improved Harris Hawks Optimization Algorithm Based Data Placement Strategy for Integrated Cloud and Edge Computing

Cloud computing is considered to facilitate a more cost-effective way to deploy scientific workflows. The individual tasks of a scientific workflow necessitate a diversified number of large states that are spatially located in different datacenters, thereby resulting in huge delays during data transmission. Edge computing minimizes the delays in data transmission and supports the fixed storage strategy for scientific workflow private datasets. Therefore, this fixed storage strategy creates huge amount of bottleneck in its storage capacity. At this juncture, integrating the merits of cloud computing and edge computing during the process of rationalizing the data placement of scientific workflows and optimizing the energy and time incurred in data transmission across different datacentres remains a challenge. In this paper, Adaptive Cooperative Foraging and Dispersed Foraging Strategies-Improved Harris Hawks Optimization Algorithm (ACF-DFS-HHOA) is proposed for optimizing the energy and data transmission time in the event of placing data for a specific scientific workflow. This ACF-DFS-HHOA considered the factors influencing transmission delay and energy consumption of data centers into account during the process of rationalizing the data placement of scientific workflows. The adaptive cooperative and dispersed foraging strategy is included in HHOA to guide the position updates that improve population diversity and effectively prevent the algorithm from being trapped into local optimality points. The experimental results of ACF-DFS-HHOA confirmed its predominance in minimizing energy and data transmission time incurred during workflow execution.

Ecology and evolution of bird sounds

Birds are among nature's most social animals. They are renowned for their group migrations, their cooperative foraging, their communal roosting, their synchronous breeding aggregations, their precise parent-offspring interactions, their coordinated group defenses and their intricate territorial and courtship rituals. In these and other contexts, and indeed in most moments of their lives, birds' capacities to navigate complex social demands and relationships can tip the balance between health or sickness, between reproductive success or failure, between life or death. It is thus no surprise that birds have evolved sophisticated systems for mediating social interactions. Foremost among these are communication signals, most evident in birds as songs, calls, color patterns and postural displays. These and other communication signals can transmit information about a signalers' status, motivations and possible future actions, for sensory and cognitive processing by signal receivers. In general, signals provide benefits for both signal senders and receivers. Consider the bright spring plumage of a male wood warbler who has established a breeding territory. The male's plumage pattern benefits him by signaling his 'ownership' of his territory, which can help him attract potential mates and preempt conflict with potential rivals. His plumage pattern also benefits his intended audiences: it informs females about the signaler's potential as a mate, and it informs other males about the degree of threat they might face were they to attempt a territory take-over. Communication signals are, in essence, a glue that maintains the cohesion of bird societies, and a currency that mediates sophisticated relationships within.

Cooperative feeding and foraging lateralization by Eden's whales off southern China

AbstractWe investigated surface feeding behaviors of Eden's whales (Balaenoptera edeni edeni) in northern Beibu Gulf, southern China, between April 3, 2018, and April 26, 2021. During 122 days at sea, 1,065 individual feeding events were recorded, and eight feeding behaviors were identified: two nonlunging (tread‐water and/or trap‐feeding, 7.7%, and a novel behavior we call “pirouette feeding,” 15.3%) and six lunging (right lateral lunging, RLL, 10.9%; left lateral lunging, 0.2%; upright lunging, 6.3%, vertical lunging, 18.5%; inverted lunging, 0.3%; cooperative lateral lunging, COL, 40.9%). During COL, 2–8 whales swam clockwise around a fish school and simultaneously performed RLL on surfacing—the first cooperative feeding behavior recorded for a Balaenoptera whale. Five lateralized feeding behaviors (entailing either a left or right rotation on the long‐body axis) accounted for 65.8% of individual feeding events, with a strong right‐side bias (99.7%). Lateralized behavior is prevalent in many vertebrates, including several species of rorquals, and we suggest that the right‐biased foraging lateralization among rorquals specifically allows them to keep their right eye on their prey (i.e., a sensory versus motor lateralization), and that this shared asymmetry among conspecifics may have preadapted Eden's whale for cooperative foraging.

Observing the nature of relationships in male bottlenose dolphins

As long-term studies reveal, bottlenose dolphin communities comprise a complex network of individual relationships. Individuals form strong bonds (e.g., mother-calf or male partnerships), transient relationships, and also compete against each other for resources. Evidence of bonded partnerships is typically revealed by the years-long study of associations with repeated sightings. However, quickly determining which individuals have close affiliations would benefit both field researchers working to describe individual behavior as they engage in cognitive activities such as cooperative foraging as well as caregivers in zoos who must decide which individuals should be housed together. Observations in aquariums are well-suited for collecting long-term, detailed information on how pairs interact because subjects can always be found and their behavior both above and below the water can be seen well. These are conditions that are rare for most (but not all) ocean-based studies. We used multiple measures to detect affiliated behavior across several dimensions of pairwise affiliation. Specifically, we used association indices to measure the frequency of affiliative behavior, the symmetry of the partnership, the tenor of interactions, and the stability of which partners were strongly affiliated from year to year. Synchronous behavior and reciprocity in proximity-seeking are two examples of potential markers of an affiliative relationship where individual choices–to join, to move together, and to leave–are visible to observers. We found that the combined measures were effective at identifying one pair that maintained a strong, stable relationship across years, one individual that formed a moderately strong trio relationship with both members of the most-affiliated pair, and one individual who was more variable in his relationships. These social markers provide a means of rapidly identifying bonded males in both aquarium and ocean settings, particularly when long-term knowledge of individual histories is not available.

Diverging cooperative prey capture strategies in convergently evolved social spiders

Sociality in spiders has evolved independently multiple times, resulting in convergently evolved cooperative breeding and prey capture. In all social spiders, prey is captured by only a subset of group members and then shared with other, non-attacking group members. However, spiders' propensity to attack prey may differ among species due to species-specific trade-offs between risks, costs and benefits of prey capture involvement. We explored whether engagement in prey attack differs among three social Stegodyphus species, using orthopteran prey, and found substantial differences. Stegodyphus mimosarum Pavesi, 1883 had a low prey acceptance rate, was slow to attack prey, and engaged very few spiders in prey attack. In S. sarasinorum Karsch, 1892, prey acceptance was high, independently of prey size, but more spiders attacked when prey was small. While medium-sized prey had higher acceptance rate in S. dumicola Pocock, 1898, indicating a preference, the number of attackers was not affected by prey size. Our results suggest that the three species may have different cooperative prey capture strategies. In S. mimosarum and S. dumicola, whose geographical ranges overlap, these strategies may represent niche specialization, depending on whether their respective cautious and choosy approaches extend to other prey types than orthopterans, while S. sarasinorum may have a more opportunistic approach. We discuss factors that can affect social spiders' foraging strategy, such as prey availability, predation pressure, and efficiency of the communal web to ensnare prey. Future studies are required to investigate to which extent species-specific cooperative foraging strategies are shaped by ontogeny, group size, and plastic responses to environmental factors.

On the evolutionary origins of the bifocal stance.

In this commentary we advance Jagiello et al.'s proposal by zooming in on the possible evolutionary origins of the "bifocal stance" that may have enabled a major transition in human cultural evolution, arguing that the evolution of the bifocal stance was driven by an explosion in cultural complexity arising from cooperative foraging, which led to a feedback loop between the ritual and instrumental stances.

Cooperative hunting in the yellow‐throated marten (Martes flavigula): Evidence for the not‐so‐solitary marten?

AbstractSpecies socio‐ecologies are a key determinant of their ecological niche, and although dynamic, linked to environmental stochasticity, availability of resources, and inter‐ and intraspecific competition, socio‐ecological theory under its prevailing framework inadequately captures the transient nature of this multi‐faceted spectrum. Cooperative foraging is an example of an advanced social behavior that functions to release species from physiological and competitive limitations and is thought to only be observed in social species. Despite the advantages of social behaviors such as cooperative foraging, some groups, for example, the mustelids, are considered to be evolutionarily constrained in terms of sociality. The martens (Martes sp.) have been used as examples of obligately solitary species, physiologically and morphologically restricted by their inability to store fat and specialization in homogeneously distributed small vertebrate prey, and therefore presumed incapable of advanced social behaviors. Here, we provide evidence of cooperative foraging in the yellow‐throated marten (Martes flavigula) in Ramnagar, India. We highlight that a tropical climate and a change in resource distribution through seasonal frugivory may release the species from typical constraints associated with martens, and other small carnivores. We argue that alongside a growing number of observations of social behaviors in solitary carnivores, our current framework for viewing socio‐ecologies may limit our understanding of these species. Advances in biologging technologies are producing new data and insights into the social complexities of wildlife that will continue to challenge the expectations our current framework and these emerging data should be used as a platform to test and refine ecological theory regarding sociality and its drivers in animal populations.

Boat disturbance affects the acoustic behaviour of dolphins engaged in a rare foraging cooperation with fishers

AbstractAcoustic behaviour is a key component of specialized foraging tactics for many aquatic species, especially cetaceans. However, in recent decades the natural environment has been increasingly exposed to a variety of anthropogenic noise sources, with the potential to impact natural foraging specializations dependent on acoustic communication. Here we evaluated whether boat noise has the potential to impact a rare foraging tactic used by individuals from a small population of the vulnerable Lahille’s bottlenose dolphin (Tursiops truncatus gephyreus) specialized in cooperation with artisanal fishers in southern Brazil. We tested whether the presence of boats changed the acoustic behaviour of dolphins when engaged in this cooperative foraging. We found that whistles and echolocation click rates were lower when boats were present, suggesting that cooperative foraging may potentially be reduced or interrupted by the presence of boats. Whistle parameters changed in response to the number, type and speed of boats, indicating a behavioural change and acoustic masking. Locally, our results reinforce the need for boat traffic regulations to minimize their impacts on these endangered dolphins and their rare cooperative tactic. From a broad perspective, we demonstrate how nonlethal impacts such as vessel disturbance can manifest subtle changes in animals’ natural behaviour and, in this case, present an insidious threat to a unique foraging specialization.

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.

Cooperative foraging during larval stage affects fitness in Drosophila

Cooperative 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 the 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.

The ability of artisanal fishers to recognize the dolphins they cooperate with

BackgroundHuman-animal interactions with mutual benefits in the wild are rare. Such positive interactions seem to require an intricate knowledge from the human side on the animals’ behavior and their habitat. In southern Brazil, dolphins and human net-casting fishers have specialized in a cooperative foraging, in which fishers report being able to identify and name dolphins. Here, we evaluate the consensus in their ability to recognize the individual dolphins they interact with. By investigating the reliability of this recognition process, we assess the pros and cons of relying on the fishers’ traditional knowledge to further understand the behavior and ecology of dolphins at the individual level. We also assess the potential role of traditional knowledge for the maintenance of this unusual interaction.MethodsWe interviewed 38 fishers using a semi-structured questionnaire. During each interview, we evaluate their recognition ability of dolphins by showing high-quality photos of dorsal fins of different dolphins, asking questions about the dolphins’ behavior and traits, and about how fishers recognize each dolphin. We also evaluated information about the fishers. Different indices were used to measure the fishers’ ability to recognize dolphins via photos, and their consensus on individual identification. These indices were modeled as functions of traits of both dolphins and fishers to investigate which ones influence the recognition process.ResultsWe found that fishers can primarily recognize dolphins by natural marks in the dorsal fin but there was little consensus in recognition. Fishers also tend to repeat the name of the most “popular” dolphins for different photos, indicating low reliability in individual recognition. We also found that fishers who learned from relatives (vertical learning) how to interact with dolphins tend to be more accurate and have higher consensus in dolphin recognition than those fishers who learned from friends (horizontal learning) or individually.ConclusionArtisanal fishers have a deep understanding of the dolphins and the system they are inserted in. However, the lack of consensus in identifying individual dolphins herein reported indicates that using their traditional knowledge to further understand dolphin behavior and ecology at the individual level requires caution. Our study also suggests that the transmission of this tradition from parents to sons can be crucial to preserve such a unique human-animal positive interaction in its original form.

Harris Hawks optimization with information exchange

The basic Harris Hawks optimization algorithm cannot take full advantage of the information sharing capability of the Harris Hawks while cooperatively searching for prey, and it is difficult to balance the exploration and development capacities of this algorithm. These factors limit the Harris Hawks optimization algorithm, such as in terms of premature convergence and ease of falling into a local optimum. To this end, an improved Harris Hawks optimization algorithm based on information exchange is proposed to optimize the continuous function and its application to engineering problems. First, an individual Harris Hawk obtains information from the shared area of cooperative foraging and the location area of collaborators, thereby realizing information exchange and sharing. Second, a nonlinear escaping energy factor with chaos disturbance is designed to better balance the local searching and the global searching of the algorithm. Finally, a numerical experiment is conducted with four benchmark test functions and five CEC-2017 real-parameter numerical optimization problems as well as seven practical engineering problems. The results show that the proposed algorithm outperforms the basic Harris Hawks optimization algorithm and other intelligence optimization algorithms in terms of the convergence rate, solution accuracy, and robustness.

A novel foraging algorithm for swarm robotics based on virtual pheromones and neural network

Swarm robotics is an emerging interdisciplinary field that has many potential real-world applications. Swarm robotics aims to produce robust, scalable, and flexible self-organizing behaviors through local interactions from a large number of simple robots. In this paper, a novel pheromone model of swarm foraging behavior is developed based on a neural network. The output of a single neuron corresponds to the density of a pheromone, which diffuses to neighboring neurons through their local connections. A neural network is updated based on the proposed evaporation model. Neural networks can often mimic the dynamics and features of pheromones. Therefore, in this work, we develop an optimization method to determine the key parameters of cooperative foraging based on mathematical modeling. The differential equation variables represent the number of foraging robots assigned different tasks. The solutions of the differential equations represent the dynamics of the foraging behavior. The key parameters that affect task allocation are determined to make optimal decision rules. Simulation experiments are conducted under different foraging scenarios. The experimental results demonstrate the effectiveness of the proposed pheromone model.

Improved Harris Hawks Optimization Based on Adaptive Cooperative Foraging and Dispersed Foraging Strategies

Harris hawks optimization (HHO) is a new swarm intelligence optimization technique. Because of its simple structure and easy to implement, HHO has attracted research interest from scholars in different fields. However, the low population diversity and the single search method in the exploration phase weakened the global search capability of the HHO algorithm. In response to these defects, this paper proposes an improved HHO algorithm based on adaptive cooperative foraging and dispersed foraging strategies. First, the adaptive cooperative foraging strategy uses three random individuals to guide the position update, which achieves cooperation between individuals. Then the cooperation behavior is embedded in the one-dimensional update operation framework, and the one-dimensional or total-dimensional update operation is adaptively selected. This way allows the algorithm to perform position update operations for a specific dimension of individual vectors with a certain probability, which improves the population diversity. Second, the dispersed foraging strategy is introduced into the HHO, forcing a part of Harris hawks to leave their current position to find more prey to obtain a better candidate solution. This way effectively avoids the algorithm falling into local optimum. Finally, a randomly shrinking exponential function is used to simulate the energy change of the prey, so that the algorithm maintains the exploration ability in the later exploitation process, effectively balancing the exploration and exploitation ability of the algorithm. The performance of the proposed ADHHO algorithm is evaluated using Wilcoxon's test on unimodal, multimodal and CEC 2014 benchmark functions. Numerical results and statistical experiments show that ADHHO provides better solution quality, convergence accuracy and stability compared with other state-of-the-art algorithms.

A Basic Bio-Inspired Camouflage Communication Frame Design and Applications for Secure Underwater Communication Among Military Underwater Platforms

Many marine mammal species, such as different kinds of whales and dolphins, live together in groups. Although having no nice eyesight, they can accomplish cooperative foraging, inter-communication and group sailing very efficiently and accurately only depending on their sound. Generally, present interception systems almost always classify biological signals as ocean noise and try to filter them out. In addition, the covertness and security are very important for many military underwater platforms (MUPs) and their formations. Based on above classification fact and covert communication demand, this article designs a basic bio-inspired camouflage communication frame (BBICCF) for secure underwater communication among military underwater platforms based on the killer whale sound. According to characteristics of the killer whales’ original call pulse trains, the original long duration call pulses (whistles and pulsed calls) are utilized as communication address codes for each MUP so as to provide disguised communication addressing support for interconnection among multiple MUPs in the same formation, and the original short duration call pulses (clicks) are used as other communication codes, so as to construct BBICCF for highly camouflaged conveying communication information. A simple and effective time-frequency (TF) contour extraction method is proposed to achieve the accurate extraction of the TF contour of the fundamental frequency of whistles and pulsed calls of killer whales for efficient classification and decoding of address codes. Next, this article provides some extensions and applications about how to let the BBICCF to be applied in conventional communication networks for MUP formation. Finally, simulation results show the effectiveness and concealment ability of designed BBICCF.