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Multi-player pursuit-evasion games are crucial for addressing the maneuver decision problem arising in the cooperative control of multi-agent systems. This paper presents a cooperative defense strategy involving cooperation and confrontation among the target, attacker, and multiple defenders based on location information only. The primary objective of the attacker is to capture the target while avoiding being captured by multiple defenders. Meanwhile, the target is confined to a restricted area and can only move within its boundaries. The proposed cooperative defense strategy aims to prevent the attacker from capturing the target while minimizing the time required to neutralize the threat. Therefore, the multiple defenders are classified into two categories: the primary defender and the auxiliary defenders. The primary defender is to prevent the attacker from approaching the target by predicting the intention of the attacker. On the other hand, the auxiliary defenders adopt a surround-shrink-capture strategy to reduce the time consumption to capture the attacker. Numerical simulations have been conducted to validate the effectiveness of the proposed strategy. [ABSTRACT FROM AUTHOR]

The random changes in the environment play a crucial role in the sustainability of ecosystems. Usually, the construction of stochastic models does not take into account the non-linear growth of intrinsic growth rate. In addition, prey only considers the collective response of the population when encountering predators and ignores the role of individual prey. To address this issue, we contemplate the dynamics of a stochastic prey–predator model with Smith growth rate and cooperative defense. The population density of prey is measured by mass, and the growth limitations are based on the proportion of unused available resources. Additionally, the grazing pattern of the predator incorporates cooperative characteristics into the functional response. We carry out existence and uniqueness analysis for the global positive solution. Then, we construct sufficient conditions for the existence of an ergodic stationary distribution of positive solutions for investigating whether prey and predator populations continue to survive. Numerical examples indicate that the Smith growth rate, cooperative defense and environmental disturbance play crucial roles in the coexistence of interacting populations. [ABSTRACT FROM AUTHOR]

We present the first documented evidence of interactions between the leopard cat (Prionailurus bengalensis euptilurus) and the invasive coypu (Myocastor coypus) in South Korea, captured through camera traps in Hwapocheon wetland park from May 2015 to April 2017. Two interactions were recorded: one showing a leopard cat carrying a carcass of sub‐adult coypu and the other a 4‐min sequence of predation and defense between two species. The observed interactions indicate active predatory behavior by the leopard cat against coypus and cooperative defense by coypus. These findings shed new light on predator–prey dynamics, highlighting the leopard cat's potential role as a predator of coypus and coypus' defensive abilities. Understanding these relationships could facilitate more effective management of invasive species and offer broader implications for ecosystem dynamics and conservation strategies. [ABSTRACT FROM AUTHOR]

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In view of the increasingly concealed,complicated,and intelligent network attacks,this paper analyzes the security protection status and network security problems faced by the water conservancy network.A cooperative defense system of water conservancy network security is proposed,and a cooperative defense control system of network security is designed according to the system.On the basis of software defined security architecture,the control layer and security layer of traditional hardware or virtualized security devices are separated.The security resource pool provides security protection,and the security control platform is responsible for management and command delivery.Furthermore,security services can be arranged according to different protection requirements to construct multiple security protection mechanisms,so as to provide technical support for realizing the cooperative defense capability of water conservancy network security featuring internal and external cooperation and linkage between the upper and lower levels.

Bacteria are inherently social organisms whose actions should ideally be studied within an interactive ecological context. We show that the exchange and modification of natural products enables two unrelated bacteria to defend themselves against a common predator. Amoebal predation is a major cause of death in soil bacteria and thus it exerts a strong selective pressure to evolve defensive strategies. A systematic analysis of binary combinations of coisolated bacteria revealed strains that were individually susceptible to predation but together killed their predator. This cooperative defense relies on a Pseudomonas species producing syringafactin, a lipopeptide, which induces the production of peptidases in a Paenibacillus strain. These peptidases then degrade the innocuous syringafactin into compounds, which kill the predator. A combination of bioprospecting, coculture experiments, genome modification, and transcriptomics unravel this novel natural product-based defense strategy. [ABSTRACT FROM AUTHOR]

Many birds join cooperative mobbing aggregations and collectively harass predators. Individuals participating in these ephemeral associations benefit by deterring the predator, but also incur energetic costs and increased risk of predation. Explaining the evolution of mobbing is challenging because individuals could prevail by selfishly seeking safety while allowing others to mob. An important step in understanding the evolution of mobbing is to identify factors affecting its expression. The ecological constraints model suggests that animals are more likely to cooperate under adverse environmental conditions, such as when local predation pressure is high. We tested this prediction by comparing the mobbing responses of several species of birds to the local abundance of their primary predator, the ferruginous pygmy-owl Glaucidium brasilianum. We used acoustic playback to elicit mobbing responses in environments where owls were common, uncommon, or rare. Stimuli were either the song of a ferruginous pygmy-owl or the mobbing calls of three of the owl’s common prey species. During each playback, we characterized mobbing responses by noting the number of species and individuals that approached the loudspeaker, as well as the closest approach by any bird. Mobbing responses to both stimuli were strong in locations where Ferruginous Pygmy-owls were common, intermediate where owls were uncommon, and weak where they were rare. This pattern persisted even after controlling for differences in species richness and composition among the three environments. Results support the ecological constraints model and provide strong evidence that intense predation pressure increases the expression of cooperative mobbing in tropical birds [Current Zoology 58 (5): 781-790, 2012].

Many birds join cooperative mobbing aggregations and collectively harass predators. Individuals participating in these ephemeral associations benefit by deterring the predator, but also incur energetic costs and increased risk of predation. Explaining the evolution of mobbing is challenging because individuals could prevail by selfishly seeking safety while allowing others to mob. An important step in understanding the evolution of mobbing is to identify factors affecting its expression. The ecological constraints model suggests that animals are more likely to cooperate under adverse environmental conditions, such as when local predation pressure is high. We tested this prediction by comparing the mobbing responses of several species of birds to the local abundance of their primary predator, the ferruginous pygmy-owl Glaucidium brasilianum. We used acoustic playback to elicit mobbing responses in environments where owls were common, uncommon, or rare. Stimuli were either the song of a ferruginous pygmy-owl or the mobbing calls of three of the owl's common prey species. During each playback, we characterized mobbing responses by noting the number of species and individuals that approached the loudspeaker, as well as the closest approach by any bird. Mobbing responses to both stimuli were strong in locations where Ferruginous Pygmy-owls were common, intermediate where owls were uncommon, and weak where they were rare. This pattern persisted even after controlling for differences in species richness and composition among the three environments. Results support the ecological constraints model and provide strong evidence that intense predation pressure increases the expression of cooperative mobbing in tropical birds. [ABSTRACT FROM AUTHOR]

Cooperation between neighbors in territory defense is expected when the cost of helping a neighbor is less than that of establishing new boundaries with a successful usurper of a neighboring territory. Cooperation has been documented in 3 species of fiddler crab and is understood to depend strongly on the relative sizes of participants—large residents will help smaller neighbors repel intermediate-sized intruders. Simply meeting these criteria does not, however, guarantee that helping occurs, and additional factors are likely to affect the benefits of providing help. We tested whether the likelihood that a large resident would help his smaller neighbor was affected by neighbor familiarity or the relative size of the smaller neighbor, by replacing neighbors with smaller, larger, or size-matched individuals and then simulating intrusions onto their territories. The likelihood of helping did not differ between familiar and unfamiliar neighbors of the same size, but it decreased when the replacement resident differed in size from the original resident. These results suggest that although residents do not recognize their neighbors individually, size acts as a cue to neighbor identity. [ABSTRACT FROM PUBLISHER]

It is well known that prey of different size and morphology often use different antipredator strategies. The prevailing notion is that this occurs because size, morphology and weaponry determine the relative effectiveness of alternative strategies, and nowhere is this assumption more entrenched than in our view of the basic decision to stay, fight or flee. Here, we use observations of coyote (Canis latrans) packs hunting deer in winter to show that two ungulates of similar size and morphology, white-tailed deer (Odocoileus virginianus) and mule deer (O. hemionus), use different antipredator strategies when encountered or attacked. Mule deer typically responded by holding their ground and aggressively defending conspecifics, and were at high risk of being attacked and killed if they fled or were undefended. White-tails always fled when pursued or attacked by coyotes. Coyotes pursued fewer white-tails than mule deer they encountered regardless of prey response. Once pursued or attacked, white-tails faced a risk of attack and capture, respectively, that was intermediate between the high and low risk mule deer groups. The overall risk of capture per encounter for white-tails was similar to that facing mule deer that confronted coyotes, which was much lower than risk facing mule deer that fled and were undefended. Contextual variables such as the opportunity to improve one's position by joining another group, moving to rugged terrain, or the presence of companions that are willing to provide defense may explain why a mixed strategy is maintained in mule deer, despite the apparently detrimental effects of flight. These examples illustrate the value of including prey behavior in models of hunting success in so far as prey defenses may not be coupled with differences in size and morphology. [ABSTRACT FROM AUTHOR]