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The predatory response of a stalking spider, Plexippus paykulli, to camouflage and prey type
Abstract
When approaching prey, a stalking predator should consider trade-offs between the probabilities of early detection (by the prey, before the strike), spontaneous departure (of prey, before the strike), prey escape (following the strike) and interference (by rivals or predators). In this study we tested the response of a jumping spider, Plexippus paykullito a background with two different camouflaging properties, and two different prey types (maggots versus adult house flies). Spiders jumped towards adult house flies from greater distances on a non-camouflaging background, but background colour had no effect on jumping distance when the prey were maggots. Spiders stalking both prey types approached more slowly when camouflaged. Our experiments suggest that jumping spiders may be responding to changes in the trade-off relationships between the probabilities of early detection, spontaneous departure, escape and interference.Copyright 1997 The Association for the Study of Animal Behaviour1997The Association for the Study of Animal Behaviour
... Evidence suggests that these spiders seek a wide range of prey, categorizing them into different groups based on prey-specific characteristics. Moreover, it has been reported that some prey capable of efficient escape, such as flies, leafhoppers and grasshoppers, are captured in a similar manner by various salticids (Forster 1977(Forster , 1982Freed 1984;Jackson 1988a;Richman & Jackson 1992;Edwards & Jackson 1993, 1994Li et al. 1996;Bear & Hasson 1997Bartos 2002;Nelson et al. 2005Nelson et al. , 2007, suggesting that at least some generalist jumping spiders use common characteristics during prey identification. However, the wide morphological diversity demonstrated by the prey, such as the presence of wings and antennae, the appearance of legs, and their sizes, shapes and colours, beg the question of how they can be recognised by the spiders. ...
... The prey identification mechanism observed in Y. arenarius is also likely to be widespread among other jumping spiders. This assumption is supported by the fact that both stalk and frontal approach exist within the routine predatory repertoires of many jumping spiders (Forster 1977(Forster , 1982Freed 1984;Jackson 1988a;Richman & Jackson 1992;Edwards & Jackson 1993, 1994Li et al. 1996;Bear & Hasson 1997Bartos 2002;Nelson et al. 2005Nelson et al. , 2007. Therefore, it is possible that similar prey characteristics employed by Y. arenarius are also used by other jumping spiders when capturing similar prey. ...
... M. Bartos Jacksonoides, Plexippus, Tauala and Trite (Forster 1982;Jackson 1988a,b;Bear & Hasson 1997;Li et al. 1999;Nelson et al. 2005;Dolev & Nelson 2016) and spartaeinae genera: Portia, Brettus, Cocalus and Cyrba (Jackson & Hallas 1986;Jackson 1990;Harland & Jackson 2000. Other than Y. arenarius (Bartos 2007(Bartos , 2008, only Phidippus has demonstrated frontal approach (Edwards & Jackson 1993, 1994 and only when capturing caterpillars (long-bodied, crawling prey); this is generally due to the fact that insect larvae have rarely been used in prey-capture studies. ...
The majority of jumping spiders are visual hunters that capture a wide range of prey. While they are known to use specific predatory techniques against different prey, their prey identification mechanisms are poorly understood. A generalist jumping spider, Yllenus arenarius, employs different predatory techniques to capture prey with two different escape potentials. The aim of the present study was to identify the characteristics used by the spider to classify prey into one of these categories. Freshly-emerged spiderlings were used in the experiments to analyse pre-programmed visual predatory preferences. The spiders were presented with: a) their natural prey with different escape potentials (flies, thrips, caterpillars) and b) video images constructed from different combinations of features of their natural prey. The images varied with regard to five characteristics: body length (short vs long images), the presence or absence of details (0 or 4 details, including head spot, antennae, legs, wings), the local motion of legs (moving vs still), the type of global motion (crawling vs non-crawling) and the direction of global motion (horizontal motion vs vertical small scale jumps). Prey-specific behaviours indicated which characteristics were used by the spider to ascertain the prey’s escape potentials. Our findings indicate that during visual prey categorization, Y. arenarius can rely solely on general prey characteristics, such as body proportions and the type of prey motion, while ignoring other stimuli, such as the presence of details and the local motion of legs. This mechanism of prey identification, based on these two easily-recognizable prey characteristics, enables fairly quick and precise categorization of a wide range of prey according to their escape potentials. The study shows how generalist jumping spiders can categorize their diverse prey into a limited number of groups and discusses the presence of the mechanism in other jumping spiders and other animals.
... Jumping spiders hunt a wide variety of invertebrates and their prey may vary according to many aspects, to mention only the ability to escape or harm the predator. There are numerous examples of conditional predatory tactics characterized by four basic aspects: different direction and velocity of approach to prey, different distances from which the prey is attacked and a variety of other preyspecific behaviours observed during predatory encounters (EDWARDS, JACKSON 1993, 1994BEAR, HASSON 1997;BARTOS 2007). Irrespective of the variety of preyspecific behavioural adaptations, most predatory encounters consist of three primary patterns: orientation, pursuit and capture (FORSTER 1977). ...
... The general pattern of hunting flies by Y. arenarius seems to express a fairly universal mode of approach and capture prey that can efficiently escape. There is Unauthenticated Download Date | 12/21/15 3:53 PM also a high degree of resemblance between the predatory behaviour of Y. arenarius and the behaviour of other non-specialized salticids approaching comparable prey (DILL 1975;FORSTER 1977FORSTER , 1982EDWARDS, JACKSON 1993, 1994BEAR, HASSON 1997). ...
... All these similarities suggest that there is a common strategy of hunting all the three types of prey. Even though there is no apparent similarity between insects from the three taxa they are hunted in a common way that seems to minimize the risk of detection of the predator by the prey (BEAR, HASSON 1997;BARTOS 2000BARTOS , 2007. ...
Predatory behaviour of Yllenus arenarius hunting flies (Diptera) was studied. The general spider's approach and capture was typical for salticids hunting prey that has high ability to escape. Two modes of approach in close proximity of prey were observed. One was typical for the majority of predatory encounters where the spider's velocity was significantly reduced with decreasing distance to prey. Stalk and movement masking were typical for this type of approach. Second mode occurred sporadically and was characterized by a high spider's velocity that was not reduced in the vicinity of the prey.
... It decreases the risk of detection and recognition by other animals, which is crucial for the fitness of both prey and predator. However, this adaptation has only been well studied and described in detail for prey species (reviewed in Ruxton et al. 2004;Stevens 2007) and ambushing predators (Heiling et al. 2005;Chittka 2001;Théry & Casas 2002), while the role of cryptic coloration during active hunting has received very little attention (Bear & Hasson 1997). The general aim of this study was to examine the influence of this adaptation on the predatory behavior and hunting success of a cryptically colored spider. ...
... Jumping spiders are known to modify their behavior in response to various cues in prey capture, in order to avoid being detected by their prey. They hunt differently when approaching dangerous prey (Harland & Jackson 2002), when the prey is facing them , when the prey's ability to defend itself is impaired (Wilcox et al. 1996; or when the prey can easily escape (Edwards & Jackson 1993;Bear & Hasson 1997;Bartos 2007). The second objective of this study was to determine whether the cryptically colored spider changes its behavior based on the camouflaging properties of the background. ...
... The second objective of this study was to determine whether the cryptically colored spider changes its behavior based on the camouflaging properties of the background. Bear and Hasson (1997) conducted a study dealing with the influence of a spider's visibility on its predatory decisions. They found that Plexippus paykulli (Audouin 1826) changed its hunting behavior depending on its visibility to the prey and prey type. ...
... It decreases the risk of detection and recognition by other animals, which is crucial for the fitness of both prey and predator. However, this adaptation has only been well studied and described in detail for prey species (reviewed in Ruxton et al. 2004;Stevens 2007) and ambushing predators (Heiling et al. 2005;Chittka 2001;Théry & Casas 2002), while the role of cryptic coloration during active hunting has received very little attention (Bear & Hasson 1997). The general aim of this study was to examine the influence of this adaptation on the predatory behavior and hunting success of a cryptically colored spider. ...
... Jumping spiders are known to modify their behavior in response to various cues in prey capture, in order to avoid being detected by their prey. They hunt differently when approaching dangerous prey (Harland & Jackson 2002), when the prey is facing them , when the prey's ability to defend itself is impaired (Wilcox et al. 1996; or when the prey can easily escape (Edwards & Jackson 1993;Bear & Hasson 1997;Bartos 2007). The second objective of this study was to determine whether the cryptically colored spider changes its behavior based on the camouflaging properties of the background. ...
... The second objective of this study was to determine whether the cryptically colored spider changes its behavior based on the camouflaging properties of the background. Bear and Hasson (1997) conducted a study dealing with the influence of a spider's visibility on its predatory decisions. They found that Plexippus paykulli (Audouin 1826) changed its hunting behavior depending on its visibility to the prey and prey type. ...
Cryptic animals tend to spend most of their lives keeping still. The majority of predators, however, including those cryptically colored, are forced to move in order to find and approach their prey. For such predators visibility may be an important factor influencing predatory behavior. Therefore we can expect differences in the way they approach their prey on backgrounds with different camouflaging properties. To test this, we examined the behavior of Yllenus arenarius Menge 1868 (Araneae: Salticidae), a cryptically colored jumping spider, hunting leafhoppers on backgrounds matching and non-matching for the spiders. Juvenile and female Y. arenarius are cryptic on light sand, but males lose their cryptic coloration for this background after their final molt. We designed an experiment to determine if increased visibility of the spiders influenced their predatory behavior. We found that background color had a significant effect on jumping distance, approaching speed and predatory success. On the light background cryptic spiders attacked from closer distances, approached prey with faster speeds and had higher success than on the dark background. Differences in approaching speed between males before and after final molt suggest a combined effect of background color and ontogenetic change of body coloration on the predatory decisions of these male spiders.
... Decisions the spiders make during predatory encounters are often based on multiple factors that may influence the outcome of the encounter. Jumping spiders have been reported to adapt their predatory behavior to various properties of their prey, such as the potential of the prey to escape (Edwards & Jackson 1993;Bear & Hasson 1997;Bartos 2007), the ability of the prey to detect the spider (Bear & Hasson 1997; or to injure the spider (Li et al. 1999;Jackson & Carter 2001). Such dangerous prey can be approached differently when it is capable of attacking the spider or when its ability to defend itself is impaired . ...
... Decisions the spiders make during predatory encounters are often based on multiple factors that may influence the outcome of the encounter. Jumping spiders have been reported to adapt their predatory behavior to various properties of their prey, such as the potential of the prey to escape (Edwards & Jackson 1993;Bear & Hasson 1997;Bartos 2007), the ability of the prey to detect the spider (Bear & Hasson 1997; or to injure the spider (Li et al. 1999;Jackson & Carter 2001). Such dangerous prey can be approached differently when it is capable of attacking the spider or when its ability to defend itself is impaired . ...
... During approach a stalking predator has to make significant decisions, e.g. about the direction, the speed of approach and the distance from which it can attack its prey. Different predatory decisions are associated, however, with different types of risk that may affect the outcome of the encounter (Bear & Hasson 1997). A stalking predator may fail if its prey runs or flies away even without perceiving the predator (spontaneous departure), if the prey perceives the predator and escapes before the strike (early detection), if the prey escapes during or after the strike (escape) and finally, if predatory sequence is interrupted by another predator or the spider's own enemy (interference). ...
Decisions made by predators during predatory encounters are often based on multiple factors that may influence the outcome of the encounters. For stalking predators their visibility to the prey and the ability of their prey to escape may be important factors influencing predatory success. Hence they are likely to adapt their predatory behavior when approaching prey on backgrounds with different camouflaging properties, but only if the prey is able to escape. To test whether jumping spiders flexibly adapt their predatory behavior to camouflaging properties of the background and prey type, the behavior of Yllenus arenarius (Araneae, Salticide), a cryptically colored jumping spider hunting leafhoppers (high escape potential) and caterpillars (low escape potential) on two types of background: matching and non-matching for the spiders was analyzed. Background color had a significant effect on the spiders’ jumping distance and their predatory success, but only if the prey had a high escape potential. No differences occurred between backgrounds if the prey could not escape. On camouflaging background the spiders attacked leafhoppers from a shorter distance and had a higher success than on non-camouflaging background.
... Jumping spiders exploit subtle signals from their prey and the environment. In addition, they tune their hunting tactics in various conditions, e.g., when they approach dangerous invertebrates (Harland & Jackson 2002), when the invertebrates are facing them , when they are highly visible to the prey (Bear & Hasson 1997), when the hunted foe's ability to defend is impaired (Wilcox et al. 1996;, when it is impossible to reach the prey directly (Jackson & Wilcox 1993b;Tarsitano & Jackson 1997) or when the prey can easily escape (Edwards & Jackson 1993;Bear & Hasson 1997;Bartos 2007). ...
... Jumping spiders exploit subtle signals from their prey and the environment. In addition, they tune their hunting tactics in various conditions, e.g., when they approach dangerous invertebrates (Harland & Jackson 2002), when the invertebrates are facing them , when they are highly visible to the prey (Bear & Hasson 1997), when the hunted foe's ability to defend is impaired (Wilcox et al. 1996;, when it is impossible to reach the prey directly (Jackson & Wilcox 1993b;Tarsitano & Jackson 1997) or when the prey can easily escape (Edwards & Jackson 1993;Bear & Hasson 1997;Bartos 2007). ...
... Distinctive prey-specific capture behavior is often stressed to be typical for two groups of salticids (Li & Jackson 1996;Nelson et al. 2005): araneophagic species (e.g., Jackson 1992) and myrmecophagic species (e.g., Jackson & van Olphen 1992). In fact, all euryphagous jumping spiders tested with different prey types were found to possess preyspecific predatory tactics (Freed 1984;Edwards & Jackson 1993;Bear & Hasson 1997;Bartos 2007), which suggests that versatility may be a common feature among all Salticidae. ...
The hunting behavior of juvenile Yllenus arenarius Menge 1868 in their first week after leaving sub-sand nests was studied. The spiders were tested with prey that can effectively escape (Homoptera) and prey that are not capable of efficient escape (Thysanoptera and larvae of Lepidoptera) in order to assess the complexity of young spider's hunting tactics. Numerous differences were found in the mode of catching the prey, which indicate that the spiders possess a conditional hunting strategy. The strategy is expressed in direction of approach, speed of approach, distance of attack and other prey-specific behaviors. The results strongly suggest the pre-programmed background of both the observed behaviors and sensitivity towards certain prey characteristics that enabled prey identification.
... Therefore the animals possessing certain limitations to their neural system are of special interest (Jackson 1992;Wilcox & Jackson 1998;Harland & Jackson 2004). Among invertebrates, conditional strategies were found in the behavior of spiders and shown to be common in salticids (Jackson 1992;Edwards & Jackson 1993, 1994Bear & Hasson 1997). ...
... Conditional strategies are present in both alternative mating tactics and predatory behavior of jumping spiders (Jackson 1992;Edwards & Jackson 1993, 1994Bear & Hasson 1997). The studies of mating behavior in numerous salticids revealed that the type of male courtship depends on the female's maturity and location (inside vs. outside the nest) (Jackson 1977). ...
... The hunting success of a stalking predator is the result of numerous decisions made during the approach stage and capture and depends primarily on the prey's ability to perceive the predator and escape. As summarized by Bear & Hasson (1997), who studied the approaching speed and the striking distance of Plexippus paykulli (Audouin 1826), a stalking predator may fail for at least four reasons: if the prey perceives the predator before the attack, releases and escapes after the strike, or spontaneously moves away in the course of its natural activity, even without perceiving the danger. Finally a competitor or the hunter's own predator may influence the outcome of the encounter (before or even after the attack). ...
Generalist predators hunt a wide range of prey that possess various characteristics affecting the predators' hunting success (e.g., size, ability to detect the threat and defend against it, potential for escape). Therefore, it can be expected that the predator should flexibly react to different prey characteristics, hunting them in prey-specific ways. For a stalking predator a crucial prey feature is its ability to escape. In this study, the alternative prey-catching tactics of a dune-dwelling salticid Yllenus arenarius Menge 1868 were analyzed. Four naturally eaten prey taxa, two with a high ability to escape (Homoptera, Orthoptera) and two with a low ability to escape (Thysanoptera, larvae of Lepidoptera), were used. Numerous differences found between the tactics indicate that Y. arenarius can not only distinguish between different types of prey, but can also employ specific tactics to catch them. The tactics belong to a conditional strategy and are manifested in alternative: a) direction of approach, b) speed of approach, and c) other prey specific behaviors.
... Given the costs of delaying an approach (e.g. increased probability of detection and the spontaneous departure of the prey), motion performance is expected to be determined economically (Bartos, 2007;Bear & Hasson, 1997;Dill, 1975). Another well-studied strategy for concealing movement is choosing appropriate opportunities associated with the attentive state (e.g. ...
... A similar tendency is observed in some stalking predators. For example, when stalking prey, the jumping spider Plexippus paykulli reduces speed with decreasing distance to the prey (Bear & Hasson, 1997). This is also found in other jumping spiders (Dill, 1975), as well as lions, P. leo (Elliott, Cowan, & Holling, 1977). ...
Male alternative reproductive tactics typically consist of territorial and sneaking tactics. In substrate-brooding fishes, sneakers try to steal fertilizations by suddenly rushing towards females from outside the spawning sites, but they are usually caught through territorial vigilance before rushing. Nevertheless, attention is seldom paid to how sneakers overcome territorial vigilance, which limits the ecological and evolutionary understanding of alternative reproductive tactics. I addressed this issue in the triplefin blenny, Enneapterygius etheostoma, by analysing sneaker behaviour recorded in the wild. Prior to rushing, sneakers gradually got closer to the spawning sites while repeatedly pausing and moving forwards but spent most of their time pausing. They moved slowly for short distances. Territorial males detected about three-quarters of the sneaking attempts. A sneaker was detected usually immediately after starting to move, indicating that movement was a major cause of sneaking failure. Longer and faster movements were detected more frequently, particularly further from spawning sites. Movements were also detected more when territorial males faced towards, rather than away from, the sneakers. This suggests that both sneaker performance and the attentive state of territorial males affect sneaking success. Sneakers more frequently started moving from behind territorial males than from in front of them, and were then less frequently detected. In sum, sneakers seemed to conceal their movements through pause-travel locomotion, adjusting their movements and choosing favourable situations. Nevertheless, they were still detected by motion-sensitive territorial males.
... But undefended prey items are also sometimes targeted indiscriminately (without a bias in attack direction), particularly when they are relatively small and have a high probability of escape (e.g. flies and hoppers: [53,[72][73][74]). When it comes to attacking more dangerous prey, we find examples of predatory specialists that strategically attack head-on; for example, some ant specialist jumping spiders consistently attack from the head end and grasp the ant's thorax in a way that avoids both bites and stings (e.g. ...
Many animals avoid predation using aposematic displays that pair toxic/dangerous defences with conspicuous achromatic warning patterns, such as high-contrast stripes. To understand how these prey defences work, we need to understand the decision-making of visual predators. Here we gave two species of jumping spiders (Phidippus regius and Habronattus trimaculatus) choice tests using live termites that had their back patterns manipulated using paper capes (solid white, solid black, striped). For P. regius, black and striped termites were quicker to capture attention. Yet despite this increased attention, striped termites were attacked at lower rates than either white or black. This suggests that the termite's contrast with the background elicits attention, but the internal striped body patterning reduces attacks. Results from tests with H. trimaculatus were qualitatively similar but did not meet the threshold for statistical significance. Additional exploratory analyses suggest that attention to and aversion to stripes is at least partially innate and provide further insight into how decision-making played out during trials. Because of their rich diversity (over 6500 species) that includes variation in natural history, toxin susceptibility and degree of colour vision, jumping spiders are well suited to test broad generalizations about how and why aposematic displays work.
... A cryptic predator may alternatively stalk the prey by approaching slowly before striking (e.g. lynx [9], jumping spiders [10] and fishes [11,12]). If the prey becomes aware of the predator, then a chase may ensue where the outcome is determined by the relative speed and agility of both animals. ...
The pursuit of prey is vital to the biology of a predator and many aspects of predatory behaviour are well-studied. However, it is unclear how a pursuit can be effective when the prey is faster than a non-cryptic predator. Using kinematic measurements, we considered the strategy of red lionfish ( Pterois volitans ) as they pursued a faster prey fish ( Chromis viridis ) under laboratory conditions. Despite swimming about half as fast as C. viridis , lionfish succeeded in capturing prey in 61% of our experiments. This successful pursuit behaviour was defined by three critical characteristics. First, lionfish targeted C. viridis with pure pursuit by adjusting their heading towards the prey’s position and not the anticipated point of interception. Second, lionfish pursued prey with uninterrupted motion. By contrast, C. viridis moved intermittently with variation in speed that included slow swimming. Such periods allowed lionfish to close the distance to a prey and initiate a suction-feeding strike at a relatively close distance (less than 9 cm). Finally, lionfish exhibited a high rate of strike success, capturing prey in 74% of all strikes. These characteristics comprise a behaviour that we call the ‘persistent-predation strategy’, which may be exhibited by a diversity of predators with relatively slow locomotion.
... Similar to C. algerina, H. termitophagus feed mostly on one prey taxon in the field -in this case, termites -and use a different strategy to hunt termites than other insects (Wesołowska & Haddad 2002). However, behavioral versatility has also been observed in other jumping spiders commonly considered as generalists (e.g., Bear & Hasson 1997;Bartos 2013). Heliophanus termitophagus was supposed to be a termitophagous specialist (Wesołowska & Haddad 2002), but the level of specialization was not tested in detail. ...
Spiders are among the most taxonomically diversified orders of predators, but data on the trophic niche of
most species are still unknown. Here, we investigated the fundamental trophic niche of two species of jumping spiders,
Cyrba algerina (Lucas, 1846) and Heliophanus termitophagus Wesołowska & Haddad, 2002, for which data on their
realized trophic niche suggest trophic specialization (feeding on other spiders or termites, respectively). We investigated
their fundamental trophic niche by means of acceptance experiments. Both species accepted a broader spectrum of prey
under laboratory conditions than in the field, suggesting they are euryphagous specialists.
... By its very definition, environmental noise confounds relevant sensory information, effectively masking an individual's presence or appearance, thereby making it more challenging to detect (Stevens 2013). The exploitation of environmental noise for concealment is well documented in predator-prey interactions (Bear and Hasson 1997), where, for example, assassin bugs become more effective at hunting web-building spiders by exploiting wind-induced vibration to disguise their approach along the web (Wignall et al. 2011). Less is known, however, about how social animals might exploit environmental noise, either to control social group size or to increase individual privacy. ...
Complex environments may place constraints on animal sensory perception. However, little is known about how ecological constraints impact the formation of animal social groups, which ultimately necessitate that conspecifics detect one another. Here we studied the fission–fusion social groups of highly social terrestrial hermit crabs (Coenobita compressus), which frequently split and recombine, requiring individuals to actively sense the location of conspecifics. We manipulated the environment by relocating abundant natural fallen leaves on the beach, testing how and why this debris may constrain social group formation. Our experiments revealed that fallen leaves impose a fundamental limit on social grouping, with experimentally simulated groups attracting significantly fewer conspecifics (75% less) if they were surrounded by leaves. This constraint on social grouping was not the result of leaves acting as a physical barrier to movement. Furthermore, leaves only hindered visual perception of conspecifics and did not hinder other modalities besides vision. By experimentally moving leaves above the horizon, such that they no longer blocked animals’ field of view, we found that the impact of these visual constraints on grouping could be effectively abolished. Broadly, these experiments elucidate how complex environments impose sensory constraints on social animals’ ability to navigate toward groups.
Significance statement
Social animals must be able to detect and orient toward conspecifics if they are to form social groups. Features of the environment, however, may impose constraints on sensory perception that interfere with the detection of conspecifics. Here we studied social hermit crabs, which form social groupings within a complex habitat that contains abundant fallen leaves along the beach–forest interface. By experimentally manipulating leaves, we show that these seemingly insignificant ecological materials create visual constraints that block the cues free-wandering individuals normally use to orient toward social groups. Our study thus reveals how common aspects of the environment can exert major constraints on sensory perception, thereby severely limiting social group formation and ultimately sociality.
... Given that the species evaluated seems to have different crypsis mechanisms, and those are related to the background where they settled, it is probable that both species can have different foraging behaviours as a result of the wide predatory behaviour in this family (Jackson & Cross, 2011). Previous research has demonstrated that jumping spiders can change their predatory repertoire depending on the background where they are camouflaged (Bear & Hasson, 1997;Bartos, Szczepko & Stanska, 2013). ...
Camouflage is used by prey to avoid detection by predators, and by predators to remain unseen by their prey. Effective camouflage can be achieved through background matching, where an animal matches the colours and patterns of the background or through disruptive coloration, where high-contrast markings disrupt the viewer’s ability to detect the animal’s shape. We used digital images to measure the body colour of two jumping spiders, Anasaitis sp. and Ilargus sp., and the substrate in which they were found (vegetation and leaf litter, respectively), in order to investigate their camouflage strategies. We evaluated the chromatic and achromatic contrast and the body patterns of spiders and both substrates modelling the perception of a bird (Cyanistes caeruleus) and a fly (Drosophila melanogaster) as potential predator and prey. Both Anasaitis sp. and Ilargus sp. were a good colour match to leaf litter in fly and avian vision; however, Ilargus sp. was a worse colour match to foliage than Anasaitis sp. Compared with its background, Anasaitis sp. also had far higher contrast stripes than Ilargus sp. We suggest that Anasaitis sp. is adopting a disruptive coloration, generalist strategy, whereas Ilargus sp. is adopting a background-matching strategy.
... The high frequency of adequate prey-specific behaviors in newly hatched spiders suggests that those behaviors are important elements of the spider's predatory strategy. The behaviors may influence the spiders' predatory success in several ways: by decreasing the risk of early detection and prey escape before the attack (stalk, movement masking, long distance of attack on leafhoppers), by increasing the precision of venom injection and avoidance of prey defense mechanisms (frontal approach), and by decreasing the probability of being noticed during the period of prey handling (and potentially eaten together with the prey) by other predators hunting nearby (jump away) (Bear & Hasson 1997;Bartos 2002). ...
We examined differences in predatory behavior between two age groups (newly hatched spiders vs. spiders over 12 weeks old) of Yllenus arenarius Menge 1868 (Araneae: Salticidae). The spiders hunted three prey taxa (leafhoppers, caterpillars and thrips) for which they possess pre-programmed predatory behavior. The aim of the study was to check the influence of age and experience on pre-programmed predatory behavior and predatory success. Age-dependent changes occurred in four aspects of prédation: direction of approach, mode of approach, distance of attack and predatory success.
... For example, African lions, Panthera leo, use long grass to conceal their approach when stalking prey (Wright 1960). The predatory behaviour of jumping spiders (Salticidae) is sometimes compared to that of a cat and these spiders approach prey faster when on low-contrast backgrounds against which they are less likely to be detected (Bear & Hasson 1997;Li et al. 2003). ...
Predatory arthropods that specialize in invading webs and preying on the resident spiders ('araneophagic predators') face special challenges. As webs are exceedingly good at transmitting vibrations, it is difficult for a web invader to move through the web and remain undetected by the spider. An araneophagic predator that generates vibrations in the web may risk prey escaping or even counterattacking. To increase the chances of an undetected approach, predators may exploit episodes of environmental noise to approach, while their prey's ability to detect them is compromised ('opportunistic smokescreen behaviour'). Here we provide the first experimental evidence of convergent opportunistic smokescreen behaviour in an araneophagic insect, Stenolemus bituberus Stal (Reduviidae), which preys on web-building spiders. We tested how two common types of environmental noise, wind and localized vibrations in the web, influence the predatory behaviour and success of assassin bugs when hunting spiders. We found that assassin bugs were more likely to catch the spider in the presence of wind. During episodes of environmental noise, assassin bugs stepped more often and walked in a more continuous manner, apparently exploiting the opportunity to approach while the prey's sensory system is less able to detect the predator. Changes in predatory behaviour in the presence of environmental noise were not evident when S. bituberus was in an unoccupied spider web. This supports our hypothesis that noise-related timing of behaviour reflects decisions made as part of a predatory strategy, rather than responses to physical disturbance.
Jumping spiders (Salticidae) are a diverse group of non‐web‐building predators and the most species‐rich spider family. The Salticidae Tribe Nannenini consists of a small group of Oriental jumping spiders that are very poorly known. The use of explicit phylogenetic analyses to establish its affinities has so far remained limited. The Nannenini genus Epidelaxia has a peculiar morphology, making its systematic position uncertain. In this study, we present a comprehensive dataset combining molecular and morphological data for Nannenini, including exemplars from all genera. This dataset comprises DNA sequences of approximately 2400 bp, including nuclear genes ( 18S , 28S and H3 ) and the mitochondrial gene CO1 , sequenced for 40 taxa (20 ingroups and 20 outgroups), along with 61 morphological characters. Notably, both DNA sequences and morphological traits were analysed separately and concurrently for the first time. The Nannenini clade is recovered with high support. Further, Epidelaxia is monophyletic and sister to Tubalaxia gen. n. This is the first hypothesis on the internal phylogenetic structure of Epidelaxia and its placement within the Tribe Nannenini. A new genus Tubalaxia gen. n. and the following new species are described: E. bharathi sp. n., E. somasundaram sp. n., T. castanea sp. n., T. aurea sp. n. The following new combination is proposed: Tubalaxia minuta (Prószyński, 1992) comb. n . Epidelaxia albostellata , E. albocruciata and E. obscura are redescribed. It is worth noting that the newly described species face endangerment due to their limited distribution and small population sizes.
The Oriental jumping spider genus Flacillula Strand, 1932 has remained taxonomically un‐revised and has never been subjected to phylogenetic evaluation. Due to its ambiguous circumscription, several species not sister to its type species were subsequently placed in it, rendering the genus a “holdall.” This study is designed to investigate the monophyly of the genus, its placement within the subtribe Simaethina Simon, 1903, and to review its composition. Using two target genes (28S, COI), we provide the first hypothesis on the internal phylogenetic structure of the genus and its placement within Simaethina. Additionally, we describe seven new species: Flacillula dothalugala sp. nov., Flacillula ellaensis sp. nov., Flacillula henryi sp. nov., Flacillula hodgsoni sp. nov., Flacillula johnstoni sp. nov., Flacillula naipauli sp. nov., and Flacillula piyasenai sp. nov. Further, the following new combinations are proposed: Iona minuta (Berland, 1929) comb. nov. and Iona nitens (Berry, Beatty & Prószyński, 1997) comb. nov. The newly described species might be endangered due to their small population size and restricted distribution in high‐altitude cloud forest. In this study, we revise the Oriental jumping spider genus Flacillula Strand, 1932 using two target genes (28S, COI) and provide the first hypothesis on the internal phylogenetic structure of the genus and its placement within Simaethina. Additionally, we describe seven new species: Flacillula dothalugala sp. nov., Flacillula ellaensis sp. nov., Flacillula henryi sp. nov., Flacillula hodgsoni sp. nov., Flacillula johnstoni sp. nov., Flacillula naipauli sp. nov., and Flacillula piyasenai sp. nov.
In this study, we constructed a simple ecosystem consisting of one-predator–two-prey escape preferred strategy (EPS)- and hunting preferred strategy (HPS)-prey) — food for prey relationship to understand how the individual’s strategic behavior, hunting and escaping affects the ecosystem. In the model, when a prey encounters its predator and the food at the same time, either hunting or escaping should be taken as priority. Hunting priority is referred to as a HPS, while escape priority is referred to as an EPS. These strategies are associated with some degree of willingness to either hunt ((Formula presented.)) or escape ((Formula presented.)). In this model, two prey species were considered. One species (HPS-prey) takes HPS and the other rabbit species (EPS-prey) takes EPS. Predators take only HPS. Simulation results showed that the density of EPS-prey was obviously higher than that of HPS-prey in the appropriate values of (Formula presented.) and (Formula presented.) in the stable state. This means that when a prey individual has appropriate willingness for both hunting and escape, EPS is more beneficial for the survival than HPS. In addition, we briefly discussed the limitation of our model and the possible future improvements.
The seasonal occurrence of soil and foliage-dwelling salticid spiders was studied in an alfalfa agroecosystem in western Saudi Arabia in 1990-1991. Six of the collected species were new to the scientific world and were described and identified. Six other salticids are reported for the first time existing in alfalfa agroecosystems in western Saudi Arabia. The salticid spiders dwelled on foliage more than in the soil. Three peaks were observed throughout the season during October, January, and August, with a pronounced peak during August. The aestivation period occurred during December. Based on their numbers, continued presence and veracious feeding behavior in the alfalfa agroecosystem, they show great potential as promising candidates for controlling major pests and thus to be included in an integrated pest management (IPM) program.
Stalking predation has been identified in many different taxa of animals. Although previous studies have identified environmental conditions that affect hunting success, we still lack a theory that explains diverse stalking patterns on the basis of these conditions. Here, I present an optimization model of a stalking hunt based on a predator's multi-stage decision-making. This incorporates the essential feature of stalking predation: as the predator attacks at a shorter distance and when it attacks before the prey notices it, its hunting success is enhanced. At each step of a hunt, the predator chooses either to shorten the distance by stalking with a risk of being noticed or to attack immediately. Major conclusions are as follows: (1) The predator attains its maximum expected hunting success just by following a simple rule: keep stalking for as long as the merit of proximity exceeds the risk of losing the merit of surprise. (2) The predator attacks at a greater distance as the environmental conditions enhance the risk of losing the merit of surprise compared to the merit of proximity. (3) The optimal attack distance is neither affected by the distance where the predator starts its hunt nor by the previous sta king success as long as the merit of proximity is sufficiently large. This constancy of the optimal attack distance can be used to test if a stalking predator follows the above simple decision-making rule.
Abstract The complete mitochondrial genome of Plexippus paykulli is a circular molecule of 14,316 bp in length, containing 13 protein-coding genes, 2 ribosomal RNAs, 22 transfer RNAs and a control region. The A + T content of the overall base composition of H-strand is 73.5% (T: 40.6%; C: 9.0%; A: 32.9%; G: 17.5%). ATP6, Cyt b, ND2, ND5 and ND4 genes begin with ATA as start codon; ATP8, ND1, ND3 and ND4L genes begin with ATT as start codon; COII and COIII genes begin with TTG as start codon; COI gene begins with AGA as start codon, while ND6 gene start with a typical ATG initiation codon. ATP6, COI, COII, COIII and ND3 genes are terminated with TAA as stop codon, ND6 ends with TA, ATP8, ND1 and ND2 end with TAG, Cyt b, ND5, ND4 and ND4L end with T.
Understanding of an ecosystem's resilience and stability requires an understanding of predatorprey dynamics because ecosystems consist of dynamical interacting subsystems that include predator-prey relationships. These relationships are closely related to the hunting-escaping strategies employed by the predator and prey. Therefore, understanding the effects of hunting and escaping strategies on ecosystems will lead to a better understanding of those systems. To this end, we constructed a spatially explicit lattice model to simulate integrative predator-prey-plant relationships. When an individual simultaneously encounters its predator and prey, either hunting or escaping should take priority. Hunting priority is referred to as a hunting preferred strategy ( HPS), while escape priority is referred to as an escape preferred strategy ( EPS). These strategies are associated with some degree of willingness to either hunt ( H) or escape ( E). In our model, the willingness of an individual to hunt or escape increased with increasing value of H or E, respectively we investigated changes in the predicted population densities for predator, prey, and plant species with changes in the values of H and E. Simulation results indicated that HPS positively contributed to ecosystem stability because those individuals that employed HPS had a greater chance of reproduction than those that employed EPS. In addition, we briefly discuss the development of our model as a tool for understanding behavioral strategies in specific predator-prey interactions.
Jumping spiders (Salticidae) are well known for their complex visual hunting behavior, but this is the first comparative study investigating their ability to catch prey in the absence of visual cues. When tested with vision occluded inside tubes, where spiders and prey (house flies, Musca domestica, and fruit flies, Drosophila spp.) could not easily evade each other, each of 42 salticid species tested caught prey in at least one of five different procedures used. Some salticids caught flies less frequently or were less aggressive when tested in petri dishes, where spiders and flies could easily evade each other. For both types of arena and prey, there were significant species differences in both success at prey-capture and tendency to respond aggressively when first contacted by flies. Additionally, there was significant positive correlation between success at catching prey and tendency to act aggressively when first contacted. Salticids resembled short-sighted spiders from other families by only attempting to catch flies when physically contacted, and by rapidly leaning forward ('lunging') to catch prey rather than leaping as they do when visual cues are available. We discuss circumstances in nature when an ability to catch prey in the absence of visual cues might be used by salticids.
The cuticular scales of spiders are flattened setae that may occur in a diverse array of colors and shapes on the dorsal and lateral surfaces of the prosoma, opisthosoma, and walking legs. In this study, we used transmission electron microscopy (of both sections and wholemounts) and scanning electron microscopy (in concert with paraffin carving) to examine the internal anatomy and ultrastructure of the cuticular scales of several species of lynx spiders (Oxyopidae) and jumping spiders (Salticidae). We also examined iridescent and noniridescent pigmented scales for species in both families. In addition to discovering intra- and interspecific and sexual differences in scale ultrastructure, the results of our research also indicate that the ultrastructure of the scales of these spiders varies directly with coloration. For iridescent scales, we found a general absence of trabeculae, a lack of pigment granules, and an almost complete fusion of the the upper and lower laminae. For noniridescent scales, we observed granules, well-formed trabeculae, and a complex internal structure consisting of internal elements within the lumen of the scale. Our examination of the scales of these spiders represents the first complete description of the ultrastructure of the cuticular scales of any species of spider. J. Morphol. 240:77–92, 1999. © 1999 Wiley-Liss, Inc.
Conditional strategies and interpopulation variation in the mating and predatory behaviour of salticid spiders are reviewed. A functional approach is adopted, and defended, in which specified behavioural phenotypes are accounted for, in large part, by specified selection factors. Courtship versatility, in which a male's behaviour depends on the female's maturity and location, is common in the Salticidae. If a male encounters an adult female in the open, where there is ample ambient light, he performs vision-dependent displays (Type 1 courtship) in front of her. If he encounters an adult female inside her nest, he uses different displays (Type 2 courtship) which are not vision–dependent and consist of various tugging, probing and jerking movements on the silk of the nest. These displays apparently send vibratory stimuli to the female. When a male encounters a subadult female inside her nest, he initially performs Type 2 courtship, then spins a second chamber on the nest and cohabits until the female moults and matures. A modification of optimal foraging theory has been used to examine factors that influence interpopulation variation in male courtship persistence. A study of five populations corroborated predictions from the model. Persistence appears to be related to female availability. Female availability is related to local phenology, which is, in turn, related to local climate. Complex examples of predatory versatility also have evolved in the Salticidae, especially in the genus Portia. All species of Portia studied are araneophagic spiders that invade other spiders' webs and practise aggressive mimicry. Portia fimbriata, uniquely among Portia species studied, uses specialised behaviour to prey on other salticids. Portia fimbriata and one of the salticids on which it preys, Euryattus sp., appear to be co-adapted to each other.
This study establishes and describes the ‘set of responses’ performed by jumping spiders in catching prey. The responses consist of 3 primary patterns, each of which is subdivided into discrete motor elements, as follows: Orientation—Alert, Swivel, and Alignment; Pursuit—Follow, Run, and Stalk; and Capture—Pre‐crouch, Crouch, and Jump. The units of behaviour selected are characteristic of the hunting sequence, and as such are of potential systematic and physiological importance. The selection was based on the aggregate behaviour of a number of disparate New Zealand species. The distance separating the spider from its prey is shown to be a determining factor in the establishment of a particular response pattern. The effects of hunger and some other response control variables on hunting behaviour are considered.
The modern arachnids are the only group of arthropods in which the main organs of sight are camera-type eyes, not unlike our own, rather than compound eyes. The copepod crustaceans also lack compound eyes, but their nauplius eyes are rarely more than a trio of simple eye-cups, with a handful of receptors each. By contrast, spider eyes at their best have retinae with 103 to 104 receptors, and in the salticid Portia the inter-receptor angles may be as small as 2.4 min of arc (Williams and McIntyre 1980), which is only six times greater than in man (cone spacing 0.42 min), and is six times smaller than in the most acute insect eye (the dragonfly Aeschna, minimum inter-ommatidial angle 14.4 min; Sherk 1978). Thus, in some spiders, but by no means all, vision is excellent, and rivalled amongst invertebrates only by the cephalopod molluscs.
The behaviour of four species (Brettus adonis, B. cingulatus, Phaeacius sp. indet. (Sri Lanka), Cyrba algerina (France & Portugal)) of a primitive salticid subfamily, Spartaeinae, was investigated in the laboratory, and observed in the field. B. adonis, B. cingulatus, and C. algerina were found to be versatile predators. As well as being, like typical salticids, effective cursorial predators of insects, they also invaded alien webs, acted as aggressive mimics by performing a variety of vibratory behaviours, captured and fed on the host spider (araneophagy), and fed on insects (klepto-parasitism) and eggs (oophagy) they found in invaded webs. Phaeacius sp. indet. neither invaded webs nor was an active cursorial predator of insects. Instead, it was a highly eucryptic, sedentary ambushing specialist that sat on tree trunks and lunged downward on passing insects. Although they did not spin prey-capture webs, each of the four species moulted in a silken structure which crudely resembled a web. Cyrba sometimes spun rudimentary enclosing nests somewhat resembling typical salticid nest. Intraspecific interactions of B. cingulatus and C. algerina consisted of visual and postcontact (tactile, chemotactic), but not vibratory, displays. These displays were similar to displays of other salticids. In Cyrba, behaviour that brings legs and palps into lengthy contact with the substratum was well developed and was possibly related to the spider’s heavy reliance on pheromonal communication. Results from this study are discussed in relation to a hypothesis of Jackson & Blest (1982), which proposes that ancestral salticids were web-builders, web-invaders, and aggressive mimics.
Plexippus paykulli (Andouin) builds dense, structurally complex nests, which detain potential prey and sometimes assist the spider in prey capture. Males use different mating tactics depending on the female’s maturity and location (courtship versatility): visual displays if the female is mature and away from her nest, vibratory displays if she is mature and in her nest, and cohabitation if she is a subadult in her nest. Other displays occur during male-male interactions. The display repertoire is large and complex and includes elements not previously described for salticids. Copulation is unusual in this salticid species: the spiders often suspend themselves away from the substrate on the female’s dragline to mate, and copulation durations are often very short.
Salticids, the largest family of spiders, have unique eyes, acute vision, and elaborate vision-mediated predatory behavior, which is more pronounced than in any other spider group. Diverse predatory strategies have evolved, including araneophagy, aggressive mimicry, myrmicophagy, and prey-specific prey-catching behavior. Salticids are also distinctive for development of behavioral flexibility, including conditional predatory strategies, the use of trial-and-error to solve predatory problems, and the undertaking of detours to reach prey. Predatory behavior of araneophagic salticids has undergone local adaptation to local prey, and there is evidence of predator-prey coevolution. Trade-offs between mating and predatory strategies appear to be important in ant-mimicking and araneophagic species.
Cat Behavior Mazokhin-Porshnyakov, G. A. 1969. Insect Vision
- P Leyhausen
Leyhausen, P. 1975. Cat Behavior. New York: Garland STPM Press. Mazokhin-Porshnyakov, G. A. 1969. Insect Vision. New York: Plenum Press. Animal Behaviour, 54, 4
Prey of the jumping spiderPhidippus
- Jackson