{"id":40948,"date":"2023-06-05T14:20:05","date_gmt":"2023-06-05T14:20:05","guid":{"rendered":"https:\/\/www.labri.fr\/perso\/barla\/blog\/?p=40948"},"modified":"2023-06-05T14:20:07","modified_gmt":"2023-06-05T14:20:07","slug":"avoiding-attack","status":"publish","type":"post","link":"https:\/\/www.labri.fr\/perso\/barla\/blog\/?p=40948","title":{"rendered":"Avoiding attack"},"content":{"rendered":"<p id=\"top\" \/>\n<p><em>by Ruxton et al.<\/em><\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Introduction<\/h3>\n\n\n\n<p>Interactions between predators and their prey can often usefully be broken down into a sequence of stages, beginning with 1) encounter (spatial and temporal proximity), and leading through: 2) detection, 3) identification, 4) approach, 5) subjugation and, ultimately, 6) consumption. &#8211; p.1 + Fig 0.1<\/p>\n\n\n\n<p>The stakes get higher for the prey the deeper into the sequence a predation event gets as it becomes less likely that the prey will be bailed-out by a later-acting defense. Similarly, the deeper into a predation event we move the more time and effort the predator will have invested in that attack and the less easily it should be convinced to give up on this particular prey item. Thus, we can see obviously very expensive defences\u2014such as autotomy of body parts occurring as very late-acting defences. &#8211; p.2<\/p>\n\n\n\n<p>There are interesting parallels between the organization of biological and human military defences. Both concern protection of valuable yet vulnerable targets, seeking optimal deployment of costly defensive &#8216;assets&#8217;. A relevant military tactic is &#8216;layered defence&#8217; in which sets of defensive resources, such as border security, naval warships, and intercontinental ballistic missiles, are deployed in sequence; when a first line of defence fails against an incoming threat a second line of defence activates to minimize further risk, and after that perhaps a third or fourth defence. &#8211; p.6 + Eq 0.1<\/p>\n\n\n\n<p>Three reasons for multiple defences have been identified: simultaneous action to maximize survival at a stage of encounter, organization across sequentially operating defences, and multiple types of enemy. &#8211; p.8<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Background matching<\/h3>\n\n\n\n<p>From the argument above we can predict that background matching should be most prevalent in species whose natural range offers predictability and uniformity of background, but this is a difficult hypothesis to test. &#8211; p.11<em> What about background complexity?<\/em><\/p>\n\n\n\n<p>Following Dukas &amp; Kamil (2001), we define a search image as 1.) a process of transitory attentional specialization that results in enhanced detection ability for particular cryptic prey types or characteristics (e.g. &#8216;a triangular shape on a wing-like feature&#8217;) and that 2.) follows from repeated visual detection of an item over a relatively short timescale. &#8211; p.15<\/p>\n\n\n\n<p>However, search image formation, and more generally pro-apostatic selection by predators on cryptic prey can provide an evolutionary pressure for the development and maintenance of polymorphism in prey species. &#8211; p.15<\/p>\n\n\n\n<p>For example, conspecific signaling can involve small multicolored spots that do not match the pattern of the background but which blend over the coarser spatial frequency of predator acuity to provide a good match to the background &#8211; p.22<\/p>\n\n\n\n<p>It has also been demonstrated that background matching can be combined with aposematic signaling by using striped patterns that blend to a cryptic color at a distance, but are effective warning patterns when viewed close up. &#8211; p.22<\/p>\n\n\n\n<p>Hence, for these predators being a generalist presents sensory constraints that may prevent enhanced detection of &#8216;private channels of communication&#8217;. &#8211; p.22<\/p>\n\n\n\n<p>An outstanding basic question is how the visual appearance of the background selects for different anti-predator strategies. &#8211; p.23<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Disruptive camouflage<\/h3>\n\n\n\n<p>After consideration of these recent theoretical and empirical developments, Stevens &amp; Merilaita (2009b) reduced the nine distinct principles of disruptive coloration that can be identified in Cott&#8217;s writing down to five: differential blending, maximum disruptive contrast, disruptive marginal patterning, surface disruption and coincident disruptive coloration. (\u2026) Hence, we feel that a receiver-centered approach\u2014 rather than a prey-phenotype-centered approach-is more suited to providing an explanation of disruptive camouflage, because it is more appropriately integrated within the sensory ecology of predator-prey interactions. &#8211; p.25 + fig 2.2<\/p>\n\n\n\n<p>Identifying examples of disruptive camouflage is challenging because confirming disruption requires establishing the perceptual response of receivers, consequently disruption cannot be defined on the basis of appearance alone. &#8211; p.26 <em>Not even in terms of effective cues?<\/em><\/p>\n\n\n\n<p>Results supported the prediction that the disruptive benefit is greater when the colors in the immediate background are perceived as belonging to different objects. &#8211; p.32<\/p>\n\n\n\n<p>Instead they observed that disruptive markings were effective irrespective of object shape, indicating that the advantage of disruption, in this experiment at least, lay in disruption of local edge information rather than shape information. &#8211; p.32<\/p>\n\n\n\n<p>This is likely because while disruption is promoted by high contrast, high-contrast stimuli are also learnt more easily. &#8211; p.33<\/p>\n\n\n\n<p>For example, an untested hypothesis is that the position of markings for edge disruption should intersect long edges to break them up, whereas disruption of feature detection processes should involve edges intersecting areas that provide the most information about object shape and identity, such as the corners of a triangular object. &#8211; p.34<\/p>\n\n\n\n<p>However the visual effect of factors such as changing viewing distance, utilization of backgrounds with different appearances, or differential targeting of receivers with high- and low-acuity visual systems, creates the potential for multiple strategies for a single color pattern that operate in different circumstances. &#8211; p.36<\/p>\n\n\n\n<p>Comparative evidence in felids suggests that species with patterns that appear to use disruptive principles, such as ocelot, clouded leopards, and jaguar, are those that occupy closed habitats (Allen et al. 2010) where dappled light creates the high contrast fragmented background that favors expression of disruptive patterns in cuttlefish, although this relationship is also predicted by selection for background matching. &#8211; p.37<\/p>\n\n\n\n<p>This result predicts that disruption should be most effective when predators detect and recognize prey infrequently, or encounter many different prey types, making search image formation more difficult, whereas if prey are common or targeted by specialized predators, less easily learnt patterns may be more advantageous. &#8211; p.39<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Countershading<\/h3>\n\n\n\n<p>Countershading coloration potentially resolves these problems by presenting light tones or areas where shadows fall and dark tones on areas receiving more irradiance, resulting in the reflected radiance over the entire body potentially being better match to the background, a mechanism termed here and elsewhere (Penacchio et al., 2015b) as a 3D background matching. &#8211; p.46<\/p>\n\n\n\n<p>An object with perfect obliterative shading will appear optically flat to an observer using shape-from-shading cues to perceive the 3D form of objects. &#8211; p.48 <em>Quite non-generic\u2026<\/em><\/p>\n\n\n\n<p>As countershading has several potential nor camouflage functions, a plausible scenario for the evolution of countershading for camouflage is exaptation of countershading for ultraviolet protection, abrasion resistance or thermoregulation. Alternatively, predation may have been the primary driving force for the initial evolution of countershading. &#8211; p.50<\/p>\n\n\n\n<p>These issues may be balanced if, as seems likely, countershading is a relatively cheap adaptation to produce and live with, such that even if it is of relatively limited effectiveness most of the time, it is still worthwhile to adopt. &#8211; p. 51<\/p>\n\n\n\n<p>Counterillumination can be broken by predators with acuity high enough that individual photophores can be detected Qohnsen, 2014; Johnsen et al.\/ 2004). Counteilluminating species can respond by decreasing the size of photophores and increasing photophore density. (\u2026) Further, bioluminescent mechanisms constrain the spectrum of light that can be produced. The presence of yellow lenses in deep-sea predators may be an adaptation to enhance differences between the color of downwelling light and that coming from counterillumination. &#8211; p.55 + [Pennacio et al 2015]<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Transparency<\/h3>\n\n\n\n<p>There are very few examples of substantially transparent species in terrestrial ecosystems\/ and even in aquatic environments they are uncommon at the surface of the water (the neustonic zone), on or near the underlying substrate (the benthic zone) or in very deep waters where the sun&#8217;s light does not penetrate sufficiently to aid vision (the aphotic zone). &#8211; p.57<\/p>\n\n\n\n<p>This suggests that there may be a trade-off for an organism between transparency to UV radiation for crypsis reasons and having a UV-absorbing outer surface to protect internal organs from damage. &#8211; p.60<\/p>\n\n\n\n<p>Hence, a fish sees the world above the surface as a bright image in Snell&#8217;s window surrounded by a much dimmer (reflected) image of the depths below. This could be a problem for plankter situated just outside Snell&#8217;s window. Light that would pass through that space if the zooplankter was not there can be refracted by the zooplankter so that its course is changed and it reaches the fish&#8217;s eye. &#8211; p.62<\/p>\n\n\n\n<p>Scattering is caused by discontinuities in refractive index. Thus, the challenge to making biological tissues transparent is mostly about making them homogeneous on the scale of wavelengths of visible light. &#8211; p.63<\/p>\n\n\n\n<p>Thus, in the midwaters of the oceans and deep lakes, the light environment is potentially at least approximately symmetrical about the vertical axis. In these waters, there is generally a complete absence of background features. (\u2026) However, in mesopelagic environments an animal with a body plan like a vertical mirror can make itself invisible to detectors viewing from side-on. &#8211; p.65<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Aposematism<\/h3>\n\n\n\n<p>Hence it is important to include modifications to behaviour when evaluating how visual cues are modified to function as aposematic signals (Rojas et al., 2014a). &#8211; p.86<\/p>\n\n\n\n<p>Visual aposematic signals are (very) often conspicuous, in the sense that they tend to attract attention from receivers, including potential predators. Visual aposematic signals often incorporate colors that contrast against the prey&#8217;s background, and they often include two or more contrasting colors over the organism&#8217;s body. &#8211; p.86<\/p>\n\n\n\n<p>What these two general hypotheses do not say, of course, is how crypsis and conspicuousness can be packaged into the same prey appearance, though Rothschild&#8217;s idea\u2014blending crypsis at a distance, conspicuousness close up\u2014is a compelling mechanism. &#8211; p.88 <em>Through halftoning maybe?<\/em><\/p>\n\n\n\n<p>Aposematism may be relatively rare, and one reason is because its initial stages are inhibited by evolutionary barriers. Even if an aposematic signal is highly advantageous when established and common, it may be maladaptive when new and rare. In particular, the initial evolution of aposematic signaling poses a problem of what we can call &#8216;number-dependent disadvantage&#8217;. Here, new, rare forms of aposematic signal are unfamiliar and therefore not associated with unprofitability to predators; organisms bearing this signal are therefore likely to be less well protected than more familiar ancestral forms. &#8211; p.90<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">The evolution and maintenance of M\u00fcllerian mimicry<\/h3>\n\n\n\n<p>Muller&#8217;s idea was very simple: predators often have to learn to avoid unpalatable (or otherwise unprofitable) prey, and in these instances there will be strong selection on unpalatable prey to adopt a similar appearance, because it serves to share the mortality cost of educating inexperienced predators. In effect, they will face selection to evolve the same set of warning signals. &#8211; p.103<\/p>\n\n\n\n<p>If predators adopt this optimal sampling strategy (or use rules of thumb that approximate the optimal strategy) then the number of unprofitable prey that should be sampled before complete rejection should rise with the density of these unprofitable prey. This is because the value of obtaining information about common prey phenotypes is higher than that of obtaining information about rare prey phenotypes. &#8211; p.109<\/p>\n\n\n\n<p>In this way, neophobia can help generate diversity by allowing rare morphs an opportunity to persist, but it does not obliterate the positive frequency dependence maintaining monomorphism at higher densities. Ironically then, the very same (optimal) sampling behavior that leads to M\u00fcllerian mimicry can also help explain the generation and maintenance of spatial polymorphisms. &#8211; p. 120<\/p>\n\n\n\n<p>In this way, selection for mimicry may generate mating preferences that further promote phenotypic uniformity. &#8211; p.121<\/p>\n\n\n\n<p>Indeed, the possibility that relationships between co-mimics can sometimes switch from mutualistic (Mullerian) to parasitic (Batesian) should not come as too much of a surprise to ecologists. &#8211; p.125<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Advertising elusiveness<\/h3>\n\n\n\n<p>We differentiate between two different types of such elusiveness signals, pursuit deterrent and perception advertisement. &#8211; p.128<\/p>\n\n\n\n<p>Hence, the types of signals considered in this chapter are signals given by prey during the close approach of a predator, that act to inform the predator that the prey would be difficult to catch and subdue. &#8211; p.129<\/p>\n\n\n\n<p>In all of the vertebrate systems considered above, prey are relatively similar in size to their predators, making the prey expensive to catch and subdue but offering a substantial reward when such investment is successful. For many systems involving vertebrate predators and invertebrate prey, the predators are much bigger than the prey offer a relatively small meal size, and predators consequently invest little in capture. In such circumstances, elusiveness signaling will be less likely to be selected for. &#8211; p.137<\/p>\n\n\n\n<p>Bergstrom &amp; Lachmann demonstrate that there is a set of necessary conditions that are sufficient to produce a stable system in which 1) prey only signal when they are reasonably sure that they have detected a predator, and 2) the predator responds to that signal by not attacking. These conditions are that: 1) There is a cost to signaling 2) This cost to signaling is not so high that signaling is never profitable 3) Prey have some means (even if imperfect) of gauging the likelihood of a predator being present, and hence their risk of attack. That is, those prey that are most &#8216;concerned&#8217; about predation are actually those that are most at risk. 4) Prey that strongly suspect the presence of the predator are more difficult to capture than those which have lower levels of suspicion. 5) The costs to the predator of attacking are not prohibitively high. &#8211; p.140<\/p>\n\n\n\n<p>They suggest that anti-predator displays may be widespread across species, due to the benefits of advertising alertness even when uncertain of the location of predators. &#8211; p.145 <em>Due to increased innate trigger mechanisms?<\/em><\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Batesian mimicry and masquerade<\/h3>\n\n\n\n<p>In other instances it may be quite fruitless to make the distinction. For example, some predator species may find a given species profitable to attack, while other predator species find it unprofitable. Even the motivation of the same individual predator to attack a given type of prey may vary according to its state of hunger or toxin burden (see section 7.5.6.1), so the profitability of a given mimic species to a given predator may be highly variable. &#8211; p.150<\/p>\n\n\n\n<p>Though it is tempting to assume that all instances of shared appearance can be interpreted as mimicry evolved via natural selection, we must remain open minded, and be prepared to accept the possibility that some instances of apparent mimicry have arisen simply as a consequence of common ancestry. &#8211; p.152<\/p>\n\n\n\n<p>Nevertheless, it will come of no surprise to find that even distantly related mimics can arrive at a phenotype similar to their model using similar mechanisms. &#8211; p.152<\/p>\n\n\n\n<p>There is an important methodological challenge to studying masquerade, related to how it is defined. Say we observe a potential herbivore overlooking a plant that mimics a stone. Is this background matching (i.e. failure to detect the plant as an entity) or masquerade (i.e. detecting it as an entity but misclassifying it as a stone)? &#8211; p.153 <em>Why is that distinction relevant?<\/em><\/p>\n\n\n\n<p>Note, however, this does not mean that mimics should never outnumber their models. Indeed, when the model is particularly unprofitable then it may pay predators to continue to avoid similar-looking prey even when there is a high &#8216;mimetic load&#8217;. &#8211; p.158<\/p>\n\n\n\n<p>&#8216;.. .the marked effects produced by removal of alternate prey or changes in their palatability are great enough that alternate prey should be included as an essential feature of mimicry theory&#8217;. &#8211; p.161<\/p>\n\n\n\n<p>Eyespots on small prey may not be especially intimidating, and yet serve to enhance the prey&#8217;s conspicuousness. However, since they may pose a legitimate threat, large prey items are generally more intimidating to small birds and the addition of eyespots further enhances the effect. &#8211; p.170<\/p>\n\n\n\n<p>Taken together, for morphological protective mimicry to be selected for, we require the prey species to benefit from exposure to visually hunting predators, no means to protect themselves directly and a suitable noxious model to resemble. &#8211; p.170<\/p>\n\n\n\n<p>More generally, if rejection of models\/mimics before attack can allow the mimics to gain a foothold while taste-rejection following attack can prevent Batesian mimics and automimics from dominating, then is taste-rejection the key reason why Batesian mimicry so rarely undermines the protection afforded to the model at high frequencies of mimics? &#8211; p.173<\/p>\n\n\n\n<p>So, predators&#8217; initial reactions to novel or deceptive prey will not necessarily be the same as their long-term reactions. Indeed, in systems where the incentive or opportunity to gain more information is high then one can anticipate strong selection for perfect mimicry. &#8211; p. 176<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Startling predators<\/h3>\n\n\n\n<p>Startling signals are secondary defenses that occur after the focal prey individual has been singled out for attack. They are also often called &#8216;deimatic signals&#8217;\u2014coined by Maldonado (1970)\u2014from the Greek for &#8216;I frighten&#8217;; and less commonly &#8216;bluff displays&#8217;. Startling signals involve stimulation of the predator&#8217;s senses that cause it to delay or break off an attack. The assumption is that even a delay in attack can confer a survival advantage to the prey. This might occur because delay gives the prey an added opportunity to flee, or added opportunity for some other event to occur (perhaps the arrival of a predator of the predator) that causes the predator to break off the attack permanently. &#8211; p.179<\/p>\n\n\n\n<p>Many species sit with their wings closed such that the undersides only are visible, and these undersides are often assumed to be relatively cryptic. However, on close approach of a predator, the insect will flick its wings open (sometimes repeatedly) to expose conspicuous patterning. This pattern can take a diversity of forms, but often includes approximately round elements called eyespots because of their visual similarity to vertebrate eyes. There is a considerable body of evidence that these conspicuous patterns induce a startle response in potential predators. &#8211; p.183<\/p>\n\n\n\n<p>This suggests that effective startle signals need not resemble particular features of predators sufficiently closely to trigger misidentification, but must simply be conspicuous and salient enough to trigger a neophobic reaction, confusion, or sensory overload. &#8211; p.184<\/p>\n\n\n\n<p>For some taxa it may be better (in terms of survival) simply to flee on first detecting a predator, rather than engage in a startle defense that may be effective on some occasions but on other occasions allows the predator to approach sufficiently closely that risk of capture is much higher if the startle signal is not effective. &#8211; p. 186<\/p>\n\n\n\n<p>Exploration of eye mimicry (see Stevens &amp; Ruxtoiv 2014 for a review) and satyric mimicry rests on how relevant non-human detectors assemble aspects of an image to achieve localization and identification of a particular object. &#8211; p. 188<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Deflecting the point of attack<\/h3>\n\n\n\n<p>Deflection involves traits that influence the initial point of contact of the predator on the prey&#8217;s body in a way that benefits the prey. These traits might be behavioural, involve morphological structures, or involve pigmentation and other appearance traits, or combinations thereof. The benefit to the prey is normally considered to be an increased likelihood of escaping the attack, and so the benefit to the prey comes at a cost to the predator. Thus, deflection may involve biasing attacks to areas of the body that can be broken off without catastrophic damage to the prey, or which are particularly difficult for the predator to grasp. &#8211; p. 189<\/p>\n\n\n\n<p>The false head can fool the predator into approaching from an angle that makes detection and flight easier for the butterfly. &#8211; p. 193<\/p>\n\n\n\n<p>Several species of lizard have the ability to shed their tail when in the grasp of a predator (an ability called &#8216;autotomy&#8217;). Such tails are often colored in a way that contrasts strongly with both the rest of the lizard&#8217;s body and with typical substrates. &#8211; p. 193<\/p>\n\n\n\n<p>It is well known that many species of ground-nesting birds exhibit conspicuous displays in response to approaching predators. These displays are generally interpreted as functioning to distract the predator, reducing the chance of the bird&#8217;s offspring being discovered and predated. &#8211; p. 197<\/p>\n\n\n\n<p>An oval &#8216;eye&#8217; may suggest to the predator that its angle to the prey is other than perpendicular. As a result, the predator may misdirect its strike or may delay its attack while it tries to maneuver into the &#8216;correct&#8217; position. This idea is currently without an empirical foundation, but is worthy of further investigation. &#8211; p. 200<\/p>\n\n\n\n<p>Since deflection relies on the predator&#8217;s visual representation of the prey, it will be affected by ambient light levels. (\u2026) It seems very plausible to us that some traits may only be effective in deflection under certain light conditions. &#8211; p. 202<\/p>\n\n\n\n<p>Specialist predators should not be fooled by deflective markings, whereas generalist predators have to accept such costs as a by-product of having evolved to be able to handle diverse prey types. Associated with this, we might expect that given sufficient practice, predators may be able to learn to ignore deflective traits, and thus we might expect that deflective traits are less common in species that have life-history traits (e.g. aggregation of individuals, outbreaking population dynamics) that would allow predators repeated experience of being deflected within a concentrated time interval.(\u2026) Specifically a generalist predator may find deflective marking difficult to combat in one species encountered infrequently if similar visual cues are useful when attacking a different species, individuals of which are encountered more frequently. This argument may provide a theoretical framework for consideration as to why some styles of signal will be more effective at deflecting than others. It also raises the testable hypothesis that prey that use deflective signals will generally not be the main prey of predatory species that they successfully deflect, and that the success of deflection will be affected by predator exposure to other prey types. Specifically, we predict that deflective traits work because they provoke an out-of-context response that is effective in other circumstances. &#8211; p. 203<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Dazzle Camouflage<\/h3>\n\n\n\n<p>Dazzle camouflage comprises coloration that interferes with predator perception of prey speed and trajectory. Accurately estimating speed and trajectory is essential for any predator that needs to know where its prey is likely to be in the near future so that it can position itself to intercept. The dazzle hypothesis is that prey coloration can interfere with these judgements. The idea is appealing because physical models of pursuit hunting show that relatively small errors in estimates of future position can dramatically adversely affect capture success. &#8211; p.205<\/p>\n\n\n\n<p>Zebra stripes create strong motion signals in directions other than the true direction of movement, supporting the hypothesis that zebra stripes make movement processing difficult. &#8211; p. 208<\/p>\n\n\n\n<p>The very simple body shape of snakes and their undulating movements create potential for movement camouflage effects that may not be effective in animals with more complex body forms. Tracking forward motion of snakes may be difficult: because of the lack of suitable reference points on a snake&#8217;s cylindrical body. Longitudinal stripes do not add reference points that track forward motion, but may create local motion signals in directions different: to the global heading of the snake as a result of undulating movements. This may be particularly effective if the snake is viewed through a partially occluding foreground, effectively creating a version of the barber pole illusion. &#8211; p. 208<\/p>\n\n\n\n<p>An interesting suggestion made by Hall et al. (2016) is that insect multilayer iridescence, which produces a striped pattern that would be perceived as moving when the predator and prey are in motion, perhaps creates a dynamic dazzle effect akin to cephalopod moving clouds. &#8211; p.210<\/p>\n\n\n\n<p>Thus it may be that perception of speed is affected by pattern contrast, but that the effect is obscured when using measures that require production of a gross motor response to capture the target. &#8211; p.211<\/p>\n\n\n\n<p>Compared to the weak or mixed results in studies focusing on speed errors, or a combination of speed and trajectory errors, the results of Hughes et al. suggest that the main effect of pattern orientation is on estimation of trajectory. (\u2026) How &amp; Zanker&#8217;s model suggests that it is likely and that a further consequence of orientation dependent trajectory errors is that stripes at a range of orientations over the whole object should create confusing multidirectional motion signals. &#8211; p. 212<\/p>\n\n\n\n<p>While orthogonally striped stimuli increasing in speed will lead to light and dark stripes being integrated (blurred), which only has the effect of reducing pattern contrast rather than producing smeared motion streak signals, parallel striped stimuli should create &#8216;speedlines&#8217; that indicate direction and velocity of motion. &#8211; p. 213<\/p>\n\n\n\n<p>Previous computer-based explorations have involved the artificial prey being in motion but the predator being effectively stationary relative to the background against which the prey are seen. Relaxing this restriction would not only be biologically realistic for mobile predators but might allow exploration of whether predators can ameliorate the effects of dazzle patterns in their prey by control of their own speed and search path trajectory. &#8211; p. 217<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Thanatosis<\/h3>\n\n\n\n<p>Thanatosis is widely interpreted as a last-resort defense against predation after active physical resistance has proved unsuccessful and fleeing is impossible. The lack of movement is suggested to inhibit further attack by the predator, and reduce the perceived need of the predator to continue to attack or constrain the prey. &#8211; p. 219<\/p>\n\n\n\n<p>Our suggestion is that the thanatosis might be effective against predators that commonly face a situation where they can subdue more than one prey item in quick succession. The predator faces a trade since the more time it spends making certain that the first prey item is dead (or sufficiently injured that it cannot escape), the more likely it is that other nearby prey items will make good their escape. In this circumstance, thanatosis works by inducing the predator to switch prematurely from one prey item to the next, and the trade-off may make it maladaptive for the predator to invest time in making absolutely sure that the first item is dead. &#8211; p. 227<\/p>\n","protected":false},"excerpt":{"rendered":"<p>by Ruxton et al. Introduction Interactions between predators and their prey can often usefully be broken down into a sequence of stages, beginning with 1) encounter (spatial and temporal proximity), and leading through: 2) detection, 3) identification, 4) approach, 5) subjugation and, ultimately, 6) consumption. &#8211; p.1 + Fig 0.1 The stakes get higher for &#8230; <a title=\"Avoiding attack\" class=\"read-more\" href=\"https:\/\/www.labri.fr\/perso\/barla\/blog\/?p=40948\" aria-label=\"Read more about Avoiding attack\">Read more<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[621],"tags":[],"class_list":["post-40948","post","type-post","status-publish","format-standard","hentry","category-books"],"_links":{"self":[{"href":"https:\/\/www.labri.fr\/perso\/barla\/blog\/index.php?rest_route=\/wp\/v2\/posts\/40948","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.labri.fr\/perso\/barla\/blog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.labri.fr\/perso\/barla\/blog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.labri.fr\/perso\/barla\/blog\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.labri.fr\/perso\/barla\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=40948"}],"version-history":[{"count":11,"href":"https:\/\/www.labri.fr\/perso\/barla\/blog\/index.php?rest_route=\/wp\/v2\/posts\/40948\/revisions"}],"predecessor-version":[{"id":40959,"href":"https:\/\/www.labri.fr\/perso\/barla\/blog\/index.php?rest_route=\/wp\/v2\/posts\/40948\/revisions\/40959"}],"wp:attachment":[{"href":"https:\/\/www.labri.fr\/perso\/barla\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=40948"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.labri.fr\/perso\/barla\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=40948"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.labri.fr\/perso\/barla\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=40948"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}