Cooperative Foraging

Species 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.

The common North Temperate open-field antsLasius neoniger, Formica schaufussi, Myrmica americana, andMonomorium minimum overlap temporally in foraging activity as well as in the sizes of arthropod prey in their diets. Arthropod prey were taken by both individual workers and cooperative worker groups, and species differed in the proportion of prey in the diet retrieved by each method. Although prey size was significantly correlated with worker size for individually retrieved prey, when cooperative foraging was considered worker size did not serve as a consistent predictor of prey choice. Contrasting social strategies of foraging and the evolution of worker body size differences are discussed.

Acoustic 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.

This 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.

Although many species have proven capable of cooperating to achieve common goals, the role of communication in cooperation has received relatively little attention. Analysis of communication between partners is vital in determining whether actions are truly cooperative rather than serendipitous or learned via trial and error (Chalmeau and Gallo in Behav Process 35:101-111, 1996a. doi: 10.1016/0376-6357(95)00049-6 , Primates 37:39-47, 1996b. doi: 10.1007/BF02382918 ). Wild cetaceans often produce sounds during cooperative foraging, playing, and mating, but the role of these sounds in cooperative events is largely unknown. Here, we investigated acoustic communication between two male bottlenose dolphins while they cooperatively opened a container (Kuczaj et al. in Anim Cogn 18:543-550, 2015b. doi: 10.1007/s10071-014-0822-4 ). Analyses of whistles, burst pulses, and bi-phonations that occurred during four contexts (i.e., no container, no animals interacting with container, one animal interacting with container, and two animals interacting with container) revealed that overall sound production rate significantly increased during container interactions. Sound production rates were also significantly higher during cooperative successes than solo successes, suggesting that the coordination of efforts rather than the apparatus itself was responsible for the phonation increase. The most common sound type during cooperative successes was burst pulse signals, similar to past recordings of cooperative events in bottlenose dolphins (Bastian in Animal sonar systems. Laboratoire de Physiologie Acoustique, Jouy-en Josas, pp 803-873, 1967; Connor and Smolker 1996).

In fish-eating North Pacific killer whales, large multi-pod aggregations of up to 100 animals often occur. These aggregations are thought to be reproductive gatherings where mating between members of different pods takes place. However, killer whales are social animals, and the role of these aggregations might also be establishing and maintaining social bonds between pods. Alternatively, it is also possible that multi-pod aggregations are in some way connected with foraging or searching for fish. In this study of killer whales in the western North Pacific, we describe multi-pod aggregations quantitatively and suggest their functional role in the life of fish-eating killer whales. We show that foraging is rare in multi-pod aggregations, whether inter-clan or intra-clan, and thus they are unlikely to play an important role in cooperative foraging. Socialising occurs more frequently in inter-clan rather than in intra-clan aggregations, which suggests the higher arousal level and possible mating during inter-clan aggregations. In summary, multi-pod aggregations of Kamchatka killer whales might be both reproductive assemblages and “clubs” of some kind in which whales gather to establish and maintain social bonds.

The painted hunting dog or African wild dog, <it>Lycaon pictus</it>, is one of the most endangered large carnivores in Africa, with extinction predicted within a few decades if their dramatic decline is not stopped. It has recently been hypothesized that because of their constraining need for helpers, group size was of major importance in obligate cooperative breeding species, and that the resulting likely existence of a threshold number of adults could create an Allee effect, increasing the group extinction risk. One example where the importance for a critical number of adults may have major repercussions for painted hunting dogs concerns baby-sitting, or pup-guarding, a behavior typical of obligate cooperative breeders. We propose that, as forgoing this behavior is costly because pup guards have the potential to decrease pup mortality, its use is costly too, especially in small packs, because helpers are strongly needed for their cooperative foraging (hunting, protecting the kill and bringing back food to the pups). We present a simple model showing how pup-guarding imposes a cost because it implies that less food per hunt is brought back to more individuals at the den. We complete these analyses with empirical tests of the effect of pack size on the probability of pup-guarding, from field data from the Hwange population in Zimbabwe. Our model, as well as our 5 years of empirical data, both suggest a critical threshold at a size of about five individuals.

Considering that extending the concept of bees partitioning into subgroups of foragers to the onlooker phase of the cooperative learning artificial bee colony (CLABC) strategy is not only feasible from algorithmic viewpoint but might reflect real behavioral foraging characteristics of bee swarms, this paper studies whether the performance of CLABC can be enhanced by developing a new model for the proposed cooperative foraging scheme. Relying on this idea, we design a modified cooperative learning artificial bee colony algorithm, referred to as mCLABC. The design procedure is built upon the definition of a partitioning scheme of onlookers allowing the generation of subgroups of foragers that might evolve differently by using specific solution search rules. In order to improve the involving of local and global search at both employed and onlooker levels, the multiple search mechanism is further tuned and scheduled according to a random selection strategy defined on the evolving parameters. Moreover, a detailed performance and robustness study of the proposed algorithm dealing with the analysis of the impact of different structural and parametric settings is conducted on benchmark optimization problems. Superior convergence performance, better solution quality, and strong robustness are the main features of the proposed strategy in comparison with recent ABC variants and advanced methods.

Do crabeater seals forage cooperatively?

Based on studies of adult behavior, the desert spider Agelenopsis aperta (Gertsch, 1934) is considered exemplary of a species exhibiting an aggressive syndrome. This study offers a first examination of the nature of interactions that juvenile A. aperta engage in during the period when sibs are clustered on a group web. We test the hypothesis that early instar A. aperta lack the aggressiveness noted for older instars. Our data set is comprised of observations of five weekly feedings offered to 818 sibling pairs, constituting an average of 4.6 replicate sib pairs from each of 174 families. At each weekly feeding, a worker termite was offered to each sib in the shared container in which they had built web retreats. We observed no cooperative foraging during the course of these feedings. Rather, most families exhibited a mix of independent foraging and non-injurious contests over prey. We present a brief overview of the occurrence and initiation of contests over prey, with particular reference to the weekly feeding in which contests first occur versus the feeding in which a seminal contest takes place (i.e., where sibs earn permanent winner versus loser status).

Multi-robot foraging systems can assist human beings to collect crops or minerals, efficiently. As being wider searching spaces, the robot control system demands scalability and reliability. For handling this limitation, in particular, swarm robotics has been considered due to its strengths such as self-organization, robustness and flexibility. However, it stipulates high initial, operating cost as employing the multi-robot foraging system. To address these drawbacks, this paper presents a novel distributed foraging mechanism. The aim is to adopt a new behavioral model regarding role division and search space division for improving energy efficiency. Simulation results demonstrate that the proposed approach outperforms an existing foraging robot system.

(1) The giant tropical ant, Paraponera clavata, exhibits graded recruitment responses, depending on the type, quantity, and quality of a food source. More ants are initially recruited to a large prey or scavenge item than to a large quantity of sugar water. (2) Individual ants encountering prey items gauge the size and/or unwieldiness of the item, regardless of the weight, when determining whether to recruit. (3) The trail pheromone of this species is often used as an orientation device by individual ants, independent of recruitment of nestmates. (4) It is proposed that the foraging behavior of P. clavata represents one of the evolutionary transitions from the independent foraging activities of the primitive ants to the highly coordinated cooperative foraging activities of many “higher” ants.

We present a novel multiuser detection (MUD) technique, based on ant colony optimization (ACO), for synchronous direct sequence code division multiple access (DS-CDMA) systems. ACO algorithms are based on the cooperative foraging strategy of real ants. While an optimal MUD design using an exhaustive search method is prohibitively complex, we show that the ACO based MUD converges to the optimal BER performance in relatively few iterations, providing 9.5% saving in computational complexity.

Aplomado falcons (Falco femoralis) often hunt in pairs when chasing birds; 29% of 349 hunts observed in eastern Mexico involved mated pairs of falcons simultaneously chasing the same prey animal; and 66% of 100 hunts of birds were tandem pursuits. Although true cooperative hunting is uncommon in birds of prey, hunts by pairs of Aplomado falcons consistently showed signs of cooperative behavior such as use of a simple coordinative signal, and some division of labor between participating individuals. Pairs were more than twice as successful as solo falcons hunting birds (44% vs. 19%), however, there was no evidence that cooperative hunting increased the range of feasible prey sizes. The frequent use of cooperative foraging in this and similar species may relate to necessities of efficient nest defense, and food and nest procurement in savannas inhabited by a diversity of nest‐site predators.

Reinforcement learning comprises an attractive solution to the multi-agent cooperation problem, due to its robustness for learning in unknown and uncertain environments. The objective of this paper is to provide learning capabilities to a group of autonomous agents in order to efficiently perform a cooperative foraging task in a distributed manner. Firstly, the D-DCM-Multi-Q learning method, presented in [1], is evaluated. To overcome the shortcomings of this method, new cooperative action selection strategies are developed. A new exploration alternative, favoring least recently visited states, is also proposed. The conducted simulation tests indicate the efficiency of suggested improvements in the case of large, unknown and stationary environments.