Explore the vast range of titles available.

Predator–prey interactions shape ecosystems and can help maintain biodiversity. However, for many of the earth’s most biodiverse and abundant organisms, including terrestrial arthropods, these interactions are difficult or impossible to observe directly with traditional approaches. Based on previous theory, it is likely that predator–prey interactions for these organisms are shaped by a combination of predator traits, including body size and species-specific hunting strategies. In this study, we combined diet DNA metabarcoding data of 173 individual invertebrate predators from nine species (a total of 305 individual predator–prey interactions) with an extensive community body size data set of a well-described invertebrate community to explore how predator traits and identity shape interactions. We found that (1) mean size of prey families in the field usually scaled with predator size, with species-specific variation to a general size-scaling relationship (exceptions likely indicating scavenging or feeding on smaller life stages). We also found that (2) although predator hunting traits, including web and venom use, are thought to shape predator–prey interaction outcomes, predator identity more strongly influenced our indirect measure of the relative size of predators and prey (predator:prey size ratios) than either of these hunting traits. Our findings indicate that predator body size and species identity are important in shaping trophic interactions in invertebrate food webs and could help predict how anthropogenic biodiversity change will influence terrestrial invertebrates, the earth’s most diverse animal taxonomic group.

Only a few studies have estimated fang replacement rate (FRR) in free-ranging snakes. We compared FRR between Crotalinae and Viperinae, two major clades of Viperidae. Crotalinae species differ by having pit organs which allow efficient strike at the prey, while, based on an earlier study, Viperinae species have relatively longer fangs. We hypothesized that FRR is related to the risk of fang damage and predicted that: (1) FRR is related positively to fang length; and (2) the FRR of Viperinae is faster than that of Crotalinae. To test these predictions, we determined the FRR, fang length, body size and hunting strategy of 21 Viperidae species, 7 Viperinae and 14 Crotalinae, controlling for allometric and phylogenetic effects. The average FRR of Viperinae was 2.6 times faster than that of Crotalinae, supporting our second prediction. However, in contradiction to our first prediction, FRR within subfamilies was related negatively to fang length. The phylogenetic analysis indicated that FRR and fang length covaried throughout the lineage, and that the relationship between FRR and fang length persisted beyond phylogenetic relatedness, implying that fang replacement of the two subfamilies followed different evolutionary pathways.

For almost a century there has been debate on the functional interpretation of desert kites. These archaeological structures have been interpreted as constructions for animal hunting or domestication purposes, sometimes for both, but with little conclusive evidence. Here, we present new evidence from a large-scale research programme. This unprecedented programme of archaeological excavations and geomatics explorations shows the unequivocal and probably exclusive function of kites as hunting traps. Considering their gigantic size, as well as the significant energy and organization required to build them, these types of traps are called mega-traps. Our research is based on five different field studies in Armenia, Jordan, Kazakhstan and Saudi Arabia, as well as on satellite imagery interpretation across the global distribution area of kites throughout the Middle East, the Caucasus and Central Asia. This hunting interpretation raises questions about the transformation of the landscape by human groups and the consequent anthropogenic impacts on local ecological equilibrium during different periods of the Holocene. Finally, the role of trapping in the hunting strategies of prehistoric, protohistoric and historic human groups is addressed.

The problem of a faster evader hunted by N p pursuers in a limited area has been a significant subject in recent years. Nevertheless, it is still challenging to develop a cooperative strategy for pursuers and an escape strategy with boundary restrictions for the evader. We solved this problem using an artificial potential function and set several interaction rules inspired by some basic concepts from ecology to achieve the pursuit and evasion phenomena. In this paper, a decentralized, real-time strategy called the dynamic cooperative hunting strategy based on the head-pursuit mechanism and the combined escape strategy is proposed. The pursuers share state information but compute their control inputs independently. For pursuers, the head-pursuit mechanism enhances each pursuer’s cognitive prediction ability. A dynamic repulsive force between pursuers is introduced to improve the cooperative ability, which enables the pursuer group to be more adaptive in a rapidly changing situation. For the evader, the combined escape strategy consists of three escape actions, namely, direct escape, border escape, and gap escape. The evader can adopt any of the three actions to escape based on the real-time relative position between each pursuer and itself and between the boundaries and itself. In addition, evaluation functions (survival time) are defined to quantify the pursuit-evasion. Extensive simulations validate the feasibility and effectiveness of the proposed method. Moreover, the experimental results demonstrate that the proposed method has application potential in mobile robots.

Many human cultures involve positive interactions with wildlife in the past and present. Lahille’s bottlenose dolphins (Tursiops gephyreus), for example, have developed tactics for coastal and estuarine foraging, which sustains a fishing practice known as “cooperative fishing” by traditional fishers in estuaries of southern Brazil. Here, we use aerial footage to describe the behavioral repertoire of the Lahille’s bottlenose dolphins and how it relates to the frequency of net casting by fishers in the Tramandaí Inlet. From nearly 8 h of footage from June 2017 to May 2018, we mainly observed dolphins foraging in the estuary inlet when fishers were present along the shoreline. Dolphins performed at least 27 clearly distinct behaviors and three types of movement patterns. A generalized additive model supported that the fishers interpret a subset of this repertoire (64%) as cues for casting their nets. The behavioral overview of the Lahille’s bottlenose dolphins presented here demonstrates not only a diverse repertoire for this population, but also its clear influence on fishers’ activities. Scientific and traditional perspectives should be integrated to better understand the ecological significance of this “cooperative fishing” for both dolphin populations and fishers that depend on them.Significance statementInteractions between different species can be very complex. It is a three-dimensional universe that comprises the behavioral and ecological characteristics of both sides, and then the dynamic they create together. In the case of the “cooperative fishing” between fishers and dolphins in southern Brazil, we still have one dimension to disclose in detail: the dolphins’ behavioral repertoire. Using aerial videos from a drone, we were able to shed light on how those dolphins behave and also how fishers coordinate their activity in response to the dolphins. We also showed that the dolphins’ behavioral repertoire is more diverse than assumed so far. Results suggest that the “cooperative fishing” seems to be based on the human’s perception of an extensive Lahille’s bottlenose dolphin behavioral repertoire during hunting. The knowledge provided here is essential to track the dynamic of this unique interaction in a given space and time.

Killer whales ( Orcinus orca ) are the apex predator in global oceans, and as such they are afforded access to prey species at all trophic levels and sizes. Due to their enhanced cognitive abilities, they are frequent predators of other ocean giants, including large sharks. Observations of these predator-prey interactions are rare globally; however, records appear to be increasing in recent years, possibly due to increased access to surveillance. Here we present reports of killer whales hunting and preying on the world’s largest fish species, the whale shark ( Rhincodon typus ), by collating and analyzing photo and video footage collected from four unique predation events spanning six years (2018 – 2024) in the southern Gulf of California. Across all events, orcas displayed a seemingly approach to collaboratively hunting and killing whale sharks, characterized by focusing on attacking the pelvic area (claspers and pelvic fins) which exsanguinates the prey and allows access to the lipid-rich liver. Photo identification of the killer whales revealed that an individual adult male “Moctezuma” was engaged in three of the four events, and the females involved in event four had previously been sighted with him. We suggest the potential existence of a specialized pod of elasmobranch-hunting killer whales occurring in the Gulf of California.

Spiders are the most abundant naturally occurring predators in vineyards and play a crucial role in natural pest control. However, vineyards are frequently sprayed with fungicides, which can harm spider communities. Fungus-resistant grape varieties can drastically reduce this fungicide input. The spiders on grape vines that were sprayed with a variable number of fungicide applications in 32 vineyards in different landscapes in Southwestern Germany were recorded. Vineyards received between 0 and 14 fungicidal sprays of varying toxicity (cumulated hazard quotients for honeybee up to 6). The majority of spiders benefited from a reduction in the number fungicide sprays, particularly Dictynidae, Philodromidae, Theridiidae and Thomisidae. Overall, space web weavers, orb web weavers and ambush hunters were most strongly affected by the frequency and toxicity of fungicide applications. The response of spiders to the landscape were highly variable and included both positive and negative effects of the percentage cover of woodland. In conclusion, reducing the cumulative hazard of fungicides by reducing the number of fungicide applications is a key element in fostering spiders in vineyards.

The piscivorous cone snail Conus tulipa has evolved a net-hunting strategy, akin to the deadly Conus geographus, and is considered the second most dangerous cone snail to humans. Here, we present the first venomics study of C. tulipa venom using integrated transcriptomic and proteomic approaches. Parallel transcriptomic analysis of two C. tulipa specimens revealed striking differences in conopeptide expression levels (2.5-fold) between individuals, identifying 522 and 328 conotoxin precursors from 18 known gene superfamilies. Despite broad overlap at the superfamily level, only 86 precursors (11%) were common to both specimens. Conantokins (NMDA antagonists) from the superfamily B1 dominated the transcriptome and proteome of C. tulipa venom, along with superfamilies B2, A, O1, O3, con-ikot-ikot and conopressins, plus novel putative conotoxins precursors T1.3, T6.2, T6.3, T6.4 and T8.1. Thus, C. tulipa venom comprised both paralytic (putative ion channel modulating α-, ω-, μ-, δ-) and non-paralytic (conantokins, con-ikot-ikots, conopressins) conotoxins. This venomic study confirms the potential for non-paralytic conotoxins to contribute to the net-hunting strategy of C. tulipa.

In this paper, we couple population dynamics and evolutionary game theory to establish a prey–predator system in which individuals in the predator population need to choose between group hunting strategies and isolated hunting strategies. This system includes two types of delay: fitness delay and hunting delay. In the absence of delays, we discuss the stability of boundary and interior equilibria. In addition, the condition that the non-delayed system undergoes transcritical bifurcation is obtained. For the delayed system, we explore the stability of the interior equilibrium and obtain the conditions for the existence of Hopf bifurcation. The conditions for determining the direction and stability of the Hopf bifurcation and the periodic variation in the periodic solution are introduced by using the normal form theory and center manifold theory. Finally, we simulate non-delayed and delayed systems. The results indicate that when the availability of prey is high, the isolated hunting strategy is the dominant strategy. When the availability of prey is low, mixed strategies appear and the proportion of the group hunting strategy increases as the availability of prey decreases. Furthermore, large delays lead to the disappearance of the mixed hunting strategy and its replacement by pure hunting strategies.

Active hunting pursuit can involve high expenditures of energy and therefore requires appropriately high-energy gains from successful prey capture. Using data loggers deployed on 12 sperm whales off the Ogasawara Islands, we regularly recorded bursts of speed during deep dives. Here, we analyzed speed, acceleration, and 3D data from these maneuvers to describe the whales’ hunting behavior. Bursts occurred at depths >400 m. The median number of bursts was only 1 per dive (range: 0 to 6 per dive), and 33% of the dives did not include any bursts, suggesting prey capture may not always require bursts. Bursts of speed averaged 3.4 ± 1.0 m s–1(mean ± SD; maximum: 8 m s–1), more than twice the mean speed observed during dives (1.5 ± 0.2 m s–1). Bursts were generally divided into two phases: (1) rapid acceleration with active stroking, and (2) drastic deceleration and changes in body orientation. Tagged whales swam up to 405 m (mean: 120 ± 88 m) during these two phases. Such behavior suggests chasing of their prey, and should incur high energy expenditure. A large percentage (20 ± 14%) of the drag-related locomotion cost of the dives was spent in bursts. Two major types of bursts were observed: inflectional bursts with turning (87%) and linear bursts without turning (13%). Our results strongly indicate that sperm whales use an active-pursuit hunting strategy and use the bursts only to catch powerful and nutritious prey (i.e. large and/or muscular) that compensate for the energetic cost of the burst.