Anti-predator Strategies Research Articles

Protection of Farms from Wolf Predation: A Field Approach

The livestock sector is facing serious challenges in combatting the increasing predation of domestic livestock. In this scenario, wild carnivores, especially wolves, represent key predators. To allow the coexistence of wild and domestic animals, defense methodologies consisting of multiple integrated antipredator strategies must be tested and implemented based on the geographical management context of each farm. This study investigated the potential of a novel antipredator method (PAN, Project Farmers-Nature in Italian) in protecting livestock (goats and horses) from wolves on a farm located in the Sibillini Mountains National Park, over a three-month period (June–September 2022). The PAN field approach involved two phases: (1) interviews with farmers and inspections of how the farm and pasture are structured and (2) monitoring predator abundance using camera traps and transects in order to understand the wildlife habits. Information on predator movement around the grazing area was shared with the farmer, who was actively involved in implementing strategies to protect livestock. The stable presence of one pair of wolves was confirmed in the grazing area, placing grazing livestock at risk. The farmer was advised to strengthen the existing antipredator strategy (herd protection dogs) by introducing two trained Maremma-Abruzzese sheepdog puppies to protect his animals. The implemented actions demonstrate how professional experts can serve as a strategic intermediary between livestock and wildlife conservation in the management of the current conflicts.

Small mammals reduce activity during high moon illumination under risk of predation by introduced predators

Predation influences prey survival and drives evolution of anti-predator behaviour. Anti-predator strategies by prey are stimulated by direct encounters with predators, but also by exposure to indicators of risk such as moonlight illumination and vegetation cover. Many prey species will suffer increased risk on moonlit nights, but risk may be reduced by the presence of dense vegetation. Determining the role of vegetation in reducing perceived risk is important, especially given predictions of increased global wildfire, which consumes vegetation and increases predation. We used remote cameras in southeastern Australia to compare support for the predation risk and habitat-mediated predation risk hypotheses. We examined the influence of moonlight and understorey cover on seven 20–2500 g mammalian prey species and two introduced predators, red foxes and feral cats. Activity of all prey species reduced by 40–70% with increasing moonlight, while one species (bush rat) reduced activity in response to increasing moonlight more sharply in low compared to high understorey cover. Neither predator responded to moonlight. Our findings supported the predation risk hypothesis and provided limited support for the habitat-mediated predation risk hypothesis. For prey, perceived costs of increased predation risk on moonlit nights outweighed any benefits of a brighter foraging environment.

Brood survival in the Red-backed Shrike Lanius collurio in eastern Poland

Brood survival as an expression of breeding success is a component of bird fitness and the principal parameter underlying bird population dynamics. The main factor limiting brood survival is predation pressure, and birds have developed anti-predator strategies by selecting safer places for building nests and breeding. Here, we examined whether nest location affected the level of predation pressure. To do so, we analyzed brood survival in a Red-backed Shrike (RBS) Lanius collurio population breeding in the low-intensive agricultural landscape of eastern Poland. The mean survival probability for the whole nesting period was 0.540 and was higher for the incubation period (0.787) than for the nestling period (0.696). Cox’s proportional hazard model did not show any significant traits describing the location of the nesting shrub or the nest’s position in the shrub that could have affected RBS brood survival. We consider the composition of the local predator community to influence brood survival more than the location of a nest in the bush. The Eurasian Magpie Pica pica is mainly responsible for RBS brood predation. Red-backed Shrikes do not defend their broods against Magpies using acoustic signals and direct contact. Since Magpies search the bushes thoroughly, the shrikes’ nest concealment strategies are ineffective in the face of this predator.

Pattern variation is linked to anti-predator coloration in butterfly larvae.

Prey animals typically try to avoid being detected and/or advertise to would-be predators that they should be avoided. Both anti-predator strategies primarily rely on colour to succeed, but the specific patterning used is also important. While the role of patterning in camouflage is relatively clear, the design features of aposematic patterns are less well understood. Here, we use a comparative approach to investigate how pattern use varies across a phylogeny of 268 species of cryptic and aposematic butterfly larvae, which also vary in social behaviour. We find that longitudinal stripes are used more frequently by cryptic larvae, and that patterns putatively linked to crypsis are more likely to be used by solitary larvae. By contrast, aposematic larvae are more likely to use horizontal bands and spots, but we find no differences in the use of individual pattern elements between solitary and gregarious aposematic species. However, solitary aposematic larvae are more likely to display multiple pattern elements, whereas those with no pattern are more likely to be gregarious. Our study advances our understanding of how pattern variation, coloration and social behaviour covary across lepidopteran larvae, and highlights new questions about how patterning affects larval detectability and predator responses to aposematic prey.

To Mob or Not to Mob: Habitat and Time of Day Influence in Mobbing Behavior in the Azure-Winged Magpie (Cyanopica cookii).

While mobbing, individuals utter distinctive calls and perform visual threatening displays. Like any other antipredatory strategies, it involves some costs (time, energy, injuries, and even death). Therefore, mobbing would be expected to vary depending on the perceived magnitude of the predation risk. Moreover, harassment behavior can also serve as a demonstration of social status and to teach juveniles to recognize predators and related behaviors. Therefore, mobbing could also persist even when predation risk is particularly low. To test our hypotheses, we used tawny owl playbacks and a taxidermy mount to elicit the mobbing response in azure-winged magpies throughout the daylight period. To classify mobbing intensity, we created five categories depending on the proximity to the owl model at which the mobbing was performed. The results revealed that mobbing behavior in azure-winged magpies was more intense where predation risk was higher: in the most suitable habitat for the tawny owl, the forest, although considerable levels of mobbing were found in the dehesa and the ecotone, which indicate that mobbing has different purposes. However, we did not find statistically significant differences in mobbing intensity depending on the time of the day. We could not show a daily adjustment of antipredator response, but magpies modulated mobbing depending on the perceived risk linked to the habitat.

Dazzled by shine: gloss as an antipredator strategy in fast moving prey.

Previous studies on stationary prey have found mixed results for the role of a glossy appearance in predator avoidance-some have found that glossiness can act as warning coloration or improve camouflage, whereas others detected no survival benefit. An alternative untested hypothesis is that glossiness could provide protection in the form of dynamic dazzle. Fast moving animals that are glossy produce flashes of light that increase in frequency at higher speeds, which could make it harder for predators to track and accurately locate prey. We tested this hypothesis by presenting praying mantids with glossy or matte targets moving at slow and fast speed. Mantids were less likely to strike glossy targets, independently of speed. Additionally, mantids were less likely to track glossy targets and more likely to hit the target with one out of the two legs that struck rather than both raptorial legs, but only when targets were moving fast. These results support the hypothesis that a glossy appearance may have a function as an antipredator strategy by reducing the ability of predators to track and accurately target fast moving prey.

Nest box entrance hole size can influence nest site selection and nest defence behaviour in Japanese tits.

Birds have the ability to assess the risk of predation in their environment and adjust their antipredation strategies based on this risk information. However, whether nest site selection has effect on subsequent nest defence behaviour has not been studied. In this study, we aimed to determine whether the Japanese tit (Parus minor) exhibits a nest-box hole size preference and whether the entrance hole sizes of nest boxes influence the nest defence behaviour of tits. We hung nest boxes with three different entrance hole sizes (diameters: 6.5cm, 4.5cm and 2.8cm) in our study sites and investigated which nest boxes were occupied by tits. In addition, by using dummy-presentation experiments, we observed the nest defence behaviours of tits that nested in boxes with 2.8cm and 4.5cm entrance holes towards common chipmunks (Tamias sibiricus, a small nest predator able to enter these holes) and Eurasian red squirrels (Sciurus vulgaris, a large nest predator unable to enter the 2.8cm entrance hole). The tits that bred in nest boxes with 2.8cm entrance holes exhibited more intense nest defence responses to chipmunks than to squirrels. In contrast, the tits that bred in nest boxes with 4.5cm entrance holes exhibited similar nest defence responses to chipmunks and squirrels. Additionally, Japanese tits that bred in nest boxes with 2.8cm entrance holes exhibited more intense behavioural responses to chipmunks than those that bred in nest boxes with 4.5cm entrance holes. Our results suggested that Japanese tits prefer to occupy nest boxes with small holes for breeding and that nest-box characteristics influenced their nest defence behaviour.

Smelling danger: Lady beetle odors affect aphid population abundance and feeding, but not movement between plants

Predator-prey interactions are complex ecological interactions that influence community structure and function. Predators affect prey density directly by consuming and removing prey from the environment. Additionally, predators can elicit non-consumptive effects in prey which influence prey survival by altering prey behavior and physiology. Key to understanding the consequences of non-consumptive effects for prey populations is determining mechanisms of detection of predation risk. With insects, olfactory cues are commonly used to convey information. It has been shown that insect prey may eavesdrop on predator odor cues as a means to determine predation risk. Herein, we assessed whether the volatile odors of the predatory insect Harmonia axyridis (multicolored Asian lady beetle) affect the behavior (feeding and dispersal behaviors) and performance (population abundance) of aphids (Myzus persicae). Aphids reduced phloem ingestion when feeding in close proximity to lady beetle cues, however, predator odors did not drive aphids to relocate on plants or to disperse across plants away from the odor source. The lack of dispersal we observed is in contrast to studies that show increased aphid movement in the presence of predators that can make physical contact with the aphids. We also found that lady beetle odor cues had a population-level effect on aphids, with 25% reduction in aphid population abundance in the presence of the odor cues. This study highlights that anti-predator strategies may differ depending on the mechanism of detection of predation risk (i.e. olfactory versus physical stimuli), or the context in which they experience them, and raises the question of whether anti-predator responses observed are maladaptive or beneficial to aphid survival. These conclusions are critical for both our basic understanding of the mechanisms driving predator-prey interactions as well as providing insight into pest-natural enemy interactions within agricultural landscapes.

Visual antipredator effects of web flexing in an orb web spider, with special reference to web decorations.

Some visual antipredator strategies involve the rapid movement of highly contrasting body patterns to frighten or confuse the predator. Bright body colouration, however, can also be detected by potential predators and used as a cue. Among spiders, Argiope spp. are usually brightly coloured but they are not a common item in the diet of araneophagic wasps. When disturbed, Argiope executes a web-flexing behaviour in which they move rapidly and may be perceived as if they move backwards and towards an observer in front of the web. We studied the mechanisms underlying web-flexing behaviour as a defensive strategy. Using multispectral images and high-speed videos with deep-learning-based tracking techniques, we evaluated body colouration, body pattern, and spider kinematics from the perspective of a potential wasp predator. We show that the spider's abdomen is conspicuous, with a disruptive colouration pattern. We found that the body outline of spiders with web decorations was harder to detect when compared to spiders without decorations. The abdomen was also the body part that moved fastest, and its motion was composed mainly of translational (vertical) vectors in the potential predator's optical flow. In addition, with high contrast colouration, the spider's movement might be perceived as a sudden change in body size (looming effect) as perceived by the predator. These effects alongside the other visual cues may confuse potential wasp predators by breaking the spider body outline and affecting the wasp's flight manoeuvre, thereby deterring the wasp from executing the final attack.

The influence of vegetation structure on sleeping site selection by chimpanzees (Pan troglodytes troglodytes).

Sleep is an important aspect of great ape life; these animals build sleeping platforms every night. In a community of chimpanzees, each subgroup selects a sleeping site where each individual builds a sleeping platform, mostly on a tree. Previous studies have measured the heights of sleeping platforms and sleeping trees to test the predation avoidance and thermoregulation hypotheses of sleeping site selection. However, it remains unclear how components of vegetation structure (vertical and horizontal) together determine the selection of sleeping sites by chimpanzees. Using botanical inventories around sleeping sites in a tropical rainforest of Cameroon, we found that chimpanzees preferentially sleep in trees measuring 40-50 cm in diameter. Regarding height, on average, sleeping trees measured 26 m and sleeping platforms were built at 16 m. To build sleeping platforms, chimpanzees preferred four tree species, which represent less than 3% of tree species in the study area. We demonstrate that the variation in abundance of tree species and the vertical and horizontal structure of the vegetation drive chimpanzee sleeping site selection. It was previously thought that preference for vegetation types was the driver of sleeping site selection in chimpanzees. However, results from this study indicate that the importance of vegetation types in sleeping site selection depends on their botanical characteristics including the variation in tree size, the abundance of all trees, the abundance of sleeping trees, and the occurrence of preferred sleeping tree species, which predict sleeping site selection. The height and diameter of trees are considered by chimpanzees when selecting a particular tree for sleeping and when selecting a site with a specific vertical structure. In addition to tree height, the abundance of smaller neighboring trees may also play a role in the chimpanzee antipredation strategy. Our results demonstrate that chimpanzees consider several vegetation parameters to establish sleeping sites.

Functions of Snake Sloughs in Bird Nests Vary with Habitats: A Test of the Anti-Predation Hypothesis.

Snake sloughs in bird nests can reduce nest predation and serve as an anti-predator strategy. However, the anti-predator function of snake sloughs in nests has only been tested twice, and it is difficult to speculate around the origin of the differences, which may well include habitat, as predator species and predation risk vary in different habitat types. Habitat would be a good place to speculate as to how differences in habitats could explain differences in responses by nest predators. Thus, we selected three different habitats, namely, the Diaoluoshan National Nature Reserve in Hainan (DLS, tropical forest), the Hainan Normal University campus (HNU, urban area), and Qingchuifeng National Forest Park in Hebei (QCF, suburban area), to verify the anti-predator function of snake sloughs in bird nests. The experimental results showed that snake sloughs in the nests reduced the predation rate of the experimental nests in HNU, whereas no such effect occurred in DLS and QCF. This suggests that the anti-predatory function of snake sloughs may not be the same over some environmental gradients and could be dependent on the species of nest predators and food resources in the habitat, which does not apply to all types of habitats.

Anti-predator strategies of adult male Central Himalayan Langurs (Semnopithecus schistaceus) in response to domestic dogs in a human-dominated landscape.

The evolution of predator-prey relationships is an important topic in primatology. Many aspects of primate society have been explained as a response to predation pressure. While predation has been discussed in broad theoretical terms, few systematically collected data exist on the subject. Furthermore, little information exists regarding the inter-male variation in responses to predators. To address this data gap, predatory dog-primate interactions were studied in a 78-member group of habituated, individually recognized Central Himalayan Langurs (CHL) (Semnopithecus schistaceus) living in a high-altitude subsistence agricultural landscape of northern India. We recorded 312 langur-dog interactions over 2 years. These predation events resulted in 15 serious attacks on adult females, infants, juveniles and sub-adults, in eight of which the prey was killed and consumed on the spot. In response to dog predation, adult males performed three types of anti-predator response behaviors: direct fighting with a predator, emitting alarm calls, fleeing and/or freezing. Differences were noted in each male's response to village dogs. The results showed that the likelihood of CHL adult males engaging in more costly counterattacks or attention getting alarm calls were better predicted by the level of investment in the group (genetic relatedness, duration of residency, social relationships), but not rank and mating rate. Long-duration resident adult males performed high and/or intermediate cost behaviors to protect vulnerable members of the group; their potential offspring, maternal siblings or cousins, and adult female social partners. Short-term residents or recent immigrant males exhibited two less energetically costly, more self-preserving behaviors, depending on their rank: (1) high-ranking short-tenure duration males, with high mating frequencies, performed flee and freeze responses; (2) low-ranking, low-mating-frequency males performed more alarm calls. Counterattacks and alarm calls were performed by adult males with relatively more experience with village dogs and were directed towards dogs with predatory histories significantly more often than dogs with non-predatory histories. Natural selection and kin selection have both contributed to the evolution of CHL anti-predator tactics.

Beetle elytra: evolution, modifications and biological functions.

Conversion of forewings into hardened covers, elytra, was a ground-breaking morphological adaptation that has contributed to the extraordinary evolutionary success of beetles. Nevertheless, the knowledge of the functional aspects of these structures is still fragmentary and scattered across a large number of studies. Here, we have synthesized the presently available information on the evolution, development, modifications and biological functions of this crucial evolutionary novelty. The formation of elytra took place in the earliest evolution of Coleoptera, very likely already in the Carboniferous, and was achieved through the gradual process of progressive forewing sclerotization and the formation of inward directed epipleura and a secluded sub-elytral space. In many lineages of modern beetles, the elytra have been distinctly modified. This includes multiple surface modifications, a rigid connection or fusion of the elytra, or partial or complete reduction. Beetle elytra can be involved in a very broad spectrum of functions: mechanical protection of hind wings and body, anti-predator strategies, thermoregulation and water saving, water harvesting, flight, hind wing folding, diving and swimming, self-cleaning and burrow cleaning, phoresy of symbiotic organisms, mating and courtship, and acoustic communication. We postulate that the potential of the elytra to take over multiple tasks has enormously contributed to the unparalleled diversification of beetles.

Predator–prey ecological system with group defense and anti-predator traits of the preys: Synergies between two important ecological actions

During smart anti-predator adaptations, preys use their size, fleeing capability and herd in their evolutionary tug-of-war with the predators. Predator–prey ecology is teeming with such examples where predators can be defeated or even killed by the group of victims, that is, preys, banding together. In this paper, we focus on a stage-structured predator–prey model with herd behavior and anti-predator phenomenon that results in the lesser ecological opportunities for predation in the presence of the smart anti-predatory constraints. It is our purpose in this paper to illustrate the combined effects of the herd behavior and anti-predator strategy on the predator–prey ecology. By constructing the model equations, we present an analytical study of the system and the occurrence of Hopf and transcritical bifurcation for the anti-predator rate as a bifurcation parameter. Conditions for co-existence under global stable interior equilibrium as well as permanence region for the survival of all species is adequately discussed. Also, the extinction of predators is explored via numerical simulations, that is, the prey population survives successfully in the habitat due to their defense mechanism and anti-predator behavior. In order to better understand the role of anti-predator traits in predator–prey system with square root functional response, we compare the theoretical and numerical results of the proposed model with a similar predator–prey system having Holling type-I functional response. Our findings show that the predator–prey dynamics under prey’s herd behavior and anti-predator tactics can have large influence on shifting the paradigm of predator–prey relationship by turning the predator–prey dynamics into the prey dominant dynamics, which is indeed, due to the smart synergy between both ecological actions. When underdog, sticking together, fights back, that would be a headache to deal with, no matter how menacing the predator is.

Anti-predator strategies of blue sheep (naur) under varied predator compositions: a comparison of snow leopard-inhabited valleys with and without wolves in Nepal

Context In Nepal, naur are usually the staple wild prey for the snow leopard, a solitary stalker hunter, and in some cases, for the wolf who hunts in a pack. We assumed that naur would adapt their anti-predatory responses to the presence of chasing and ambushing predators in the Manang Valley, where there are snow leopards and wolves, and in the Nar Phu valley, an area where there is only the snow leopard. Aims The aim of this study was to determine if there were differences in anti-predator strategies (vigilance, habitat selection and escape terrain) of naur in two valleys over two seasons, spring and autumn. Methods In spring 2019, we conducted a reconnaissance survey on the status of the naur and its habitat in the Manang and Nar Phu valleys of the Annapurna Conservation Area, Nepal. In spring and autumn 2020 and 2021, we observed 360 focal naur individuals (180 individuals in each valley), using the vigilance behaviour methodology to examine the behaviour of the naur. Key results There was little difference in the size of the naur groups between the Manang and Nar Phu valleys. The naur were twice as vigilant in Manang (15%), where there are snow leopards and wolves, as they were in Nar Phu (9%), with only snow leopards. The distance from the naur to escape cover was significantly shorter in Manang than in Nar Phu valley. Naur used significantly more rolling terrain in Nar Phu than in Manang. Conclusions The return of wolves to the Manang valley may have resulted in an increase in the level of naur vigilance. Most likely, the wolves in Manang have already had an effect on the female-to-young-ratio, and this effect will possibly have important consequences for the naur population, as well as at the ecosystem level in the future. Other key determining factors, such as the climate crisis and changes in local resources, could have a significant impact on the naur population, indicating the need for more research. Implications The findings of this study would provide valuable baseline information for the design of a science-based conservation strategy for conservation managers and scientists on naur, snow leopards and wolves.

Testing drivers of acoustic divergence in cicadas (Cicadidae: Tettigettalna).

Divergence in acoustic signals may have a crucial role in the speciation process of animals that rely on sound for intra-specific recognition and mate attraction. The acoustic adaptation hypothesis (AAH) postulates that signals should diverge according to the physical properties of the signalling environment. To be efficient, signals should maximize transmission and decrease degradation. To test which drivers of divergence exert the most influence in a speciose group of insects, we used a phylogenetic approach to the evolution of acoustic signals in the cicada genus Tettigettalna, investigating the relationship between acoustic traits (and their mode of evolution) and body size, climate and micro-/macro-habitat usage. Different traits showed different evolutionary paths. While acoustic divergence was generally independent of phylogenetic history, some temporal variables' divergence was associated with genetic drift. We found support for ecological adaptation at the temporal but not the spectral level. Temporal patterns are correlated with micro- and macro-habitat usage and temperature stochasticity in ways that run against the AAH predictions, degrading signals more easily. These traits are likely to have evolved as an anti-predator strategy in conspicuous environments and low-density populations. Our results support a role of ecological selection, not excluding a likely role of sexual selection in the evolution of Tettigettalna calling songs, which should be further investigated in an integrative approach.

Behavioural responses to chemical cues of predators differ between fire salamander larvae from two different habitats

AbstractPrey organisms need to detect predators and respond with adequate antipredator behaviours. To recognize predators, chemosensory cues play a pivotal role, particularly in aquatic ecosystems, where sight may be restricted. However, it is less known whether the ability to use these cues, enabling appropriate antipredator behaviour, varies between subpopulations occupying different habitats with different predation risks. We examined antipredator behaviour of wild‐caught larval fire salamanders (Salamandra salamandra) from two different habitats, ponds and streams. Ponds and streams are inhabited by habitat‐specific predators, such as alpine newts (Ichthyosaura alpestris), which only occur in ponds. We confronted larvae from both habitats with either tap water (control) or tap water that had contained alpine newts (newt treatment) and investigated potential behavioural differences in activity and shelter emergence. In the activity test, pond larvae, but not stream larvae, were significantly less active when faced with chemical cues (potentially kairomones) from newts than those faced with a control stimulus, but stream larvae generally exhibited significantly lower activity than pond larvae. In the shelter‐emergence test, larvae from both habitats spent significantly less time outside a shelter in the newt treatment than in control water. This suggests that larval fire salamanders, independent of their habitat, recognize chemical cues from potential predators and alter their behaviour accordingly. Larvae of both habitats were able to detect and use chemical cues released from potential predators, but they differed slightly in their response to these chemical cues. This finding reflects varying antipredator strategies in response to the habitat‐specific differences.

How local antipredator response unbalances the rock-paper-scissors model.

Antipredator behavior is a self-preservation strategy present in many biological systems, where individuals join the effort in a collective reaction to avoid being caught by an approaching predator. We study a nonhierarchical tritrophic system, whose predator-prey interactions are described by the rock-paper-scissors game rules. We perform a set of spatial stochastic simulations where organisms of one out of the species can resist predation in a collective strategy. The drop in predation capacity is local, which means that each predator faces a particular opposition depending on the prey group size surrounding it. Considering that the interference in a predator action depends on the prey's physical and cognitive ability, we explore the role of a conditioning factor that indicates the fraction of the species apt to perform the antipredator strategy. Because of the local unbalancing of the cyclic predator-prey interactions, departed spatial domains mainly occupied by a single species emerge. Unlike the rock-paper-scissors model with a weak species because of a nonlocal reason, our findings show that if the predation probability of one species is reduced because individuals face local antipredator response, the species does not predominate. Instead, the local unbalancing of the rock-paper-scissors model results in the prevalence of the weak species' prey. Finally, the outcomes show that local unevenness may jeopardize biodiversity, with the coexistence being more threatened for high mobility.

Quiet islands in a world of fear: Wolves seek core zones of protected areas to escape human disturbance

The Anthropocene continuously escalates the challenges and threats faced by large carnivores in human-dominated landscapes. Given their unique conservation and management requirements, detailed insights into their behaviour in relation to human-induced risks are crucial to designing landscapes of coexistence for people and predators, containing key features such as nature conservation areas. Adaptations like selection or avoidance of areas at certain times reveal the dynamic perception of large carnivores to risk-landscapes and the trade-offs with potential resources. This study investigates these ideas by applying a habitat-selection approach to GPS collared wolves in Belovezhskaya Pushcha National Park (Belarus) to quantify fine-scale avoidance of human disturbance. Our results indicate that wolves selected strongly for areas of higher nature protection within the national park. They also avoided human disturbance from settlements and roads, but mediated their behaviour depending on the shifting risk throughout the day and night. They selected for more open areas during darkness. Seasonal and sex-based differences shifted avoidance, such as females being more avoidant of settlements. This suggests evidence of a successful anti-predator strategy against humans. Our study offers some of the most detailed and novel insights into wolf spatio-temporal avoidance of disturbance in the context of protected areas, which is imperative for fine-tuning management measures for continued coexistence and effective conservation of this functionally important species.

Spatial differentiation of background matching strategies along a Late Pleistocene range expansion route

Late Pleistocene climate changes have deeply impacted the range dynamics of temperate species. While the genetic legacy of these dynamics has been widely investigated, little is known about their phenotypic consequences. Anti-predatory strategies offer intriguing opportunities to study phenotypic evolution in response to dispersal dynamics since the ability to avoid predation can be pivotal for populations colonising new environments. Here we investigated the spatial differentiation of background colour matching strategies along a Late Pleistocene range expansion route of a temperate species, the Tyrrhenian tree frog Hyla sarda. Using common-garden experiments, we tested whether individuals from the source area (Sardinia) and individuals from the newly founded area (Corsica) differ in two components of the camouflage strategy: colour change abilities and background choice behaviour. We found a remarkable spatial structure in both colour change abilities and background choice behaviour, across the expansion range. Tree frogs from the source area displayed higher colour change abilities and a more pronounced preference for a greener background, with respect to tree frogs from the newly colonised area. Our results support the intriguing hypothesis that Late Pleistocene biogeographic history might be an overlooked major player in shaping current spatial patterns of phenotypic traits variation across animal populations.