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Human‐modified habitats rarely yield outcomes that are aligned with conservation ideals. Landscapes that are subdivided by roads are no exception, precipitating negative impacts on populations due to fragmentation, pollution, and road kill. Although many populations in human‐modified habitats show evidence for local adaptation, rarely does environmental change yield outright benefits for populations of conservation interest. Contrary to expectations, we report surprising benefits experienced by amphibian populations breeding and dwelling in proximity to roads. We show that roadside populations of the wood frog, Rana sylvatica, exhibit better locomotor performance and higher measures of traits related to fitness compared with frogs from less disturbed environments located further away from roads. These results contrast previous evidence for maladaptation in roadside populations of wood frogs studied elsewhere. Our results indicate that altered habitats might not be unequivocally detrimental and at times might contribute to metapopulation success. While the frequency of such beneficial outcomes remains unknown, their occurrence underscores the complexity of inferring consequences of environmental change.

Among antipredator behaviours, escaping and hiding in a refuge are widespread in nature. Frequently, threatened prey flee towards a refuge nearby, if available. Therefore, refuge proximity may affect the fleeing strategy of a prey. In this work, I tested this hypothesis in Epidalea calamita, a cursorial toad that flees by means of intermittent runs. In a linear runway in standardized conditions, toads were recorded while conducting a short-distance (refuge at 70 cm), a medium-distance (refuge at 140 cm, divided in two 70-cm tracks), and a long-distance trial (refuge at 210 cm, divided in three 70-cm tracks), in a random sequence. Video analyses permitted to calculate sprint speed and run rates (number of runs per meter) in each track. Distance to refuge affected toad flight strategy. Toads started flights at a faster speed in the short-distance trials. In the medium- and the long-distance trials, toads accelerated after the first track, seemingly not motivated by refuge proximity. In these trials, run rate was greater in the first tracks. Altogether, these findings suggest that threatened toads respond firstly with slow, intermittent movements, and only shift to less intermittent, faster sprints if the threat persists. However, run rate was lower in the short-distance trial than in the first tracks of the other trials, suggesting straighter (and faster) flight toward the refuge when it is close. The effects of refuge proximity were greater in males, which (jointly with faster sprint speed) could reflect a greater conspicuousness of males to predator resulting in better escape strategies.

Foraging is key for most animals, because their energy and matter income depend on food ingestion. However, animals may respond adaptively to perceived competitor and/or predator proximity by modifying their foraging rates. Increased foraging activity is expected to improve the chances of succeeding in competition. However, the benefits of increased foraging activity could be offset by the risks of increased conspicuousness to predators. Plus, starvation may have counteracting or additive effects on foraging behaviour. Here, we test these hypotheses in larval Iberian ribbed newts (Pleurodeles waltl). We estimated foraging rates of individuals haphazardly assigned to either a restricted or an unrestricted-feeding regime, in water with (1) self-odour as control, (2) predator Dytiscus sp. chemical cues, and (3) competitor conspecific larva chemical cues. Treatments were presented in a random sequence. Newt larvae responded to either predator or conspecific chemical cues by increasing foraging rates relative to the control. Conspecific chemical cues increased foraging rates over the other two treatments. Feeding regime did not modify larva response to perceived predator and competitor proximity. Increased foraging rates in the presence of conspecific chemical cues could simultaneously improve larval energetic status to face competition and reduce prey available for the competitor. Intermediate foraging rates in the presence of predator chemical cues suggest a trade-off between the benefits (likely improved energetic status or accelerated metamorphosis) and the costs (likely increased conspicuousness) of increased food ingestion. These results prove that larval newts adjust foraging rates to perceived predator and competitor proximity.

Prevalence of morphological abnormalities usually is less than 5% in most amphibian populations (Ouellet et al. 1997, Vandenlangenberg et al. 2003, Mester et al. 2015). Morphology is closely related to whole-organism performance in amphibians (Zamora-Camacho 2018, Zamora- Camacho and Aragón 2019a), and thus, is under strong selection (Watkins 1996). Therefore, this low frequency likely reflects the negative effects of abnormalities on whole-organism performance (Zamora-Camacho and Aragón 2019b). However, amphibian populations are experiencing an alarming increase in morphological abnormality rates worldwide (Lanoo 2008, Johnson and Bowerman 2010, Laurentino et al. 2016). Amongst these, the most common are limb malformations, such as misshapen or fused limbs, and missing, or presence of extra limbs and toes (Harris et al. 2008, Johnson and Bowerman 2010, Reeves et al. 2013).

Animals may face trade-offs when several simultaneous functions or processes compete for limiting resources. In that context, allocation of resources to the most fitness-enhancing competing function can be prioritized. Immune response and locomotor performance are relevant fitness components, mainly due to their important roles as defence against pathogens and predators, respectively. However, both promote oxidative stress and consume energy and metabolites. Consistently, trade-offs between immune response and locomotion have been reported in some taxa. In this work, we examine whether an immune challenge hinders short-distance swimming speed of adult Iberian ribbed newts, Pleurodeles waltl. To that end, we inoculated Escherichia coli cell wall lipopolysaccharide (LPS), an innocuous antigen that triggers an immune response, in the sole pads of experimental newts, and phosphate buffer saline, with no physiological effect, in those of control newts. We estimated immune response as sole pad swelling and calculated swimming speed from videos of newts swimming towards a refuge nearby, 24 h and 7 days after inoculation. Sole pad swelling was greater in LPS-inoculated newts, but short-distance swimming speed was not affected by the immune challenge. These results could indicate priority allocation of resources to locomotion, which might be a consequence of compensatory mechanisms capable of avoiding locomotion impairment due to immune challenge. In any case, these findings could highlight the importance of short-distance escape as an antipredator strategy.

1. How predation events experienced by preys can shape phenotypic traits through the ontogenetic development of the interacting species should be a key issue in Evolutionary and Conservation Biology. 2. Locomotor performance plays a fundamental role on the fitness of many animals, mainly because it enhances ability to fleeing from predators. Predators represent indeed a capital selective force on prey, mainly because they end prey life. However, predators may also damage prey by other means, such as injuries caused by failed attacks. This damage can severely affect locomotion, among several other aspects of prey fitness. In the case of anuran tadpoles, failed predator attacks often result in injured tails, which reduces swimming performance. However, little is known about lasting effects of those failed attacks on fleeing capabilities after metamorphosis. 3. In this work, we clipped 55% tail length of pre-tail-resorption stage anaesthetized larval Pelobates cultripes toads, and compared metamorph hindlimb length and jump distance with metamorphs resulting from anaesthetized and non-anaesthetized non-clipped controls. Previous findings showed that this treatment produced metamorphs with reduced body condition. 4. Results herein suggest that partial tail loss in tadpoles diminishes jumping performance of resultant metamorphs. This effect is likely a consequence of tail-clipped tadpoles developing shorter hindlimbs as metamorphs, which is parallel to their reduced body condition. 5. Therefore, predator attacks in the tail may be less potentially mortal than those in the head and body, but have costs in terms of an efficient antipredatory response that persist in post-metamorphic stage. This effect might compromise metamorph ability to survive subsequent predator attacks.

How predation events experienced by preys can shape phenotypic traits through the ontogenetic development of the interacting species should be a key issue in Evolutionary and Conservation Biology. Locomotor performance plays a fundamental role on the fitness of many animals, mainly because it enhances ability to fleeing from predators. Predators represent indeed a capital selective force on prey, mainly because they end prey life. However, predators may also damage prey by other means, such as injuries caused by failed attacks. This damage can severely affect locomotion, among several other aspects of prey fitness. In the case of anuran tadpoles, failed predator attacks often result in injured tails, which reduces swimming performance. However, little is known about lasting effects of those failed attacks on fleeing capabilities after metamorphosis. In this work, we clipped 55% tail length of pre-tail-resorption stage anaesthetized larval Pelobates cultripes toads, and compared metamorph hindlimb length and jump distance with metamorphs resulting from anaesthetized and non-anaesthetized non-clipped controls. Previous findings showed that this treatment produced metamorphs with reduced body condition. Results herein suggest that partial tail loss in tadpoles diminishes jumping performance of resultant metamorphs. This effect is likely a consequence of tail-clipped tadpoles developing shorter hindlimbs as metamorphs, which is parallel to their reduced body condition. Therefore, predator attacks in the tail may be less potentially mortal than those in the head and body, but have costs in terms of an efficient antipredatory response that persist in post-metamorphic stage. This effect might compromise metamorph ability to survive subsequent predator attacks.

Coloration is often key in animal communication, and is frequently subjected to strong natural and sexual selection, often with opposed directions: natural selection typically favors cryptic colorations whereas sexual selection may favor conspicuous colorations. Also, different coloration traits may convey different pieces of information. Plus, coloration may vary among habitats, mirroring local selective pressures. In this work, we test if color parameters (luminosity, chroma, and hue) of back and throat are related to different life-history and morphological traits in Epidalea calamita toads. Furthermore, we check possible variability of color parameters between agrosystem and natural habitat toads. Toad coloration was sexually dimorphic, which suggests a role of coloration in sexual communication. Moreover, coloration correlated with age, body size, hindlimb length, and sprint speed. These findings suggest communication based on coloration beyond sex recognition: coloration could act as a signal of overall quality of bearers, with a potential role in mate choice. Moreover, coloration differed between habitats. Greener backs in agrosystem toads could indicate greater intensity of predator pressure, while their higher saturation could indicate greater investment in mate attraction. This result is aligned with previous findings that agrosystem toads respond to reduced lifespan with greater reproductive investment.

Se presenta el diseño de CRECONAN, un cuestionario sobre conocimientos y actitudes hacia anfibios y reptiles dirigido a estudiantes de ESO

Hiding behavior is key for most animals’ fitness, but it entails costs that must be balanced with benefits. Most research on this potential trade-off focuses on hiding time. However, other features that might mirror an actual energy investment on hiding behavior, such as burrowing depth, have long been neglected. In this work, we examined energy-demanding burrowing behavior of Iberian spadefoot toads (Pelobates cultripes), which hide in burrows they dig with the aid of a hard spade on each hindlimb. Namely, we tested whether toads increased burrowing depth as a response to soil dryness and predator kairomones, in search for subterranean humidity and predator avoidance, respectively. To do so, we measured burrowing depth of adult toads under three different treatments in a repeated-measures design: damp sand, dry sand and sand with boar predator kairomones. We also checked potential effects of sex and morphology (snout–vent length, body mass, hindlimb length and spade length) on burrowing depth. Morphometric variables measured were not good predictors of burrowing depth: Mainly, body mass showed a negative relationship with burrowing depth. However, despite their greater body mass, females burrowed deeper than males in the damp sand treatment. Albeit, contradicting our hypothesis, males did not respond to the presence of predator kairomones, while females reduced their burrowing depth. This result could be a consequence of predator-induced stress affecting burrowing ability. Also, both females and males burrowed shallower in the dry-sand treatment than in the others, which could be due to substrate instability or to dehydration.

Studies on the impacts of variation of biotic interactions at key life cycle stages are crucial to understand the interface between ecological and developmental processes. Predators exert a major impact on prey fitness. Although direct consumption entails the greatest effect, predators can affect prey by means of other mechanisms. For instance, injuries inflicted by failed predation attempts can jeopardize prey fitness, even beyond the short-term. In anuran tadpoles, failed predation typically results in partial tail loss, which is known to reduce swimming speed. However, the potential consequences of tadpole partial tail loss after metamorphosis remain understudied. Because tail materials could be important in conforming metamorph body, we assess the effects of tadpole partial tail loss on metamorph body size in Iberian spadefoot toads Pelobates cultripes. We clipped 55% tail length of pre-tail-resorption stage anesthetized tadpoles, and compared their body size as metamorphs with anesthetized and non-anesthetized non-tail-clipped controls. Also, we tested whether tail length correlated with metamorph body size of individuals of the control groups. Tail-clipped tadpoles produced smaller metamorphs than both controls (the bdy size of metamorphs from both controls was similar), which could incur costs in mid-term survival or time to first reproduction. This effect could be particularly important in areas with introduced predators, if autochthonous tadpoles lack defenses against them. Results suggest that materials resorbed from tadpole tail tissues might be reallocated into metamorph body, according to the negative effect of shorter tails in a correlational analysis, and clipped tails in an experimental test, on metamorph body size.

Habitat alterations in agroecosystems may damage amphibian immune capacity. As agroecosystem extension is increasing worldwide, broader-context knowledge on the effects of agroecosystem stressful conditions on amphibian immune capacity is crucial for understanding and management of amphibian global declines. However, most studies on ecoimmunology assume synchronal among-group immune-response peaks, and focus on immune response after standardized time lapses, neglecting its progression. Herein, I compared inflamatory response short-term progression of agroecosystem and natural-habitat female and male natterjack toads Epidalea calamita, by measuring swelling response, once per hour, 6 h following an artificial immune challenge with innocuous antigen phytohemagglutinin. I also compared maximum magnitude of swelling response, irrespective of the moment when it was reached. Habitat differences arose only 3 h after challenge, when natural-habitat toads showed greater swelling response. Maximum magnitude of swelling response was similar in toads from both habitats. However, agroecosystem toads showed a delayed swelling response as compared with natural-habitat conspecifics, probably as a consequence of agroecosystem stressful conditions. Such a delay suggests a weaker immune capacity, and consequently impaired anti-pathogen performance. Regarding sex, swelling response magnitude did not differ between males and females. Female swelling response peaked earlier, but that of males was more sustained in time, which contradicts general across-taxa findings that males show impaired immune response. Interestingly, results suggest that measuring swelling response only after some standardized period following stimulation may be a simplistic approach and produce unrealistic results. Consequently, studies on ecoimmunology should implement swelling response progression in order to produce unbiased science.

Human-modified habitats rarely yield outcomes that are aligned with conservation ideals. Landscapes that are subdivided by roads are no exception, precipitating negative impacts on populations due to fragmentation, pollution, and road kill. Although many populations in human modified habitats show evidence for local adaptation, rarely does environmental change yield outright benefits for populations of conservation interest. Contrary to expectations, we report surprising benefits experienced by amphibian populations breeding and dwelling in proximity to roads. We show that roadside populations of the wood frog, Rana sylvatica, exhibit better locomotor performance and higher measures of traits related to fitness compared with frogs from less disturbed environments located further away from roads. These results contrast previous evidence for maladaptation in roadside populations of wood frogs studied elsewhere. Our results indicate that altered habitats might not be unequivocally detrimental, and at times might contribute to metapopulation success. While the frequency of such beneficial outcomes remains unknown, their occurrence underscores the complexity of inferring consequences of environmental change.

As an evolutionary force, predation increases predator fitness, whereas prey future fitness is reduced to zero. Mesopredators are subjected to pressures as both predator and prey, which could generate trade-offs between predatory and anti-predatory behaviours. We subjected larvae of the mesopredator Pleurodeles waltl newt to a potential conflict of interest between reducing predation risk and fulfilling nutritional requirements. For this, we performed an experiment with a factorial design: (1) to induce different urges as predators, individuals underwent either restricted or unrestricted feeding; and (2) to induce different urges as prey, individuals were exposed to environments with and without predator snake kairomones. We recorded activity rate, swim rate, flight initiation distance (FID) and escape speed. FID increased in the presence of kairomones, as predicted by escape theory when the costs of not fleeing are greater than those of fleeing. Escape speed increased in the presence of kairomones, but only in restricted feeding larvae, probably due to lower body weight because of reduced food intake. We detected no effect of treatment on activity or swim rates. Predation risk apparently outweighed the costs of feeding opportunities lost rather than generated a behavioural trade-off. Collectively, the data suggested a greater effect of predator avoidance than of prey acquisition.

The effects of age on performance of life-history traits are diverse, but a common outcome is senescence, an irreversible deterioration of physical and physiological capabilities of older individuals. Immune response is potentially bound to senescence. However, little is known about immune response ageing in amphibians. In this work, we test the hypothesis that amphibian early immune response is reduced in older individuals. To this end, we captured adult natterjack toads (Epidalea calamita) and inoculated them with phytohemagglutinin, an innocuous protein that triggers a skinswelling immune response whose magnitude is directly proportional to the ability of the individual to mount an immune response. We measured early swelling immune response (corresponding to an innate-response stage) hourly, for six hours, and we calculated the area under the curve (AUC) for each individual's time series, as a measure of immune response magnitude incorporating time. We estimated toad age by means of phalanx skeletochronology. Swelling and AUC decreased with age. Therefore, in accordance with our predictions, early immune response seems subject to senescence in these toads. Reduced ability to get over infections due to senescence of immune respose might be together with a worse functioning of other organs and systems among the causes of lower survival of older specimens

Studying the causes of parasite geographic distribution is relevant to understand ecological and evolutionary processes that affect host populations as well as for species conservation. Temperature is one of the most important environmental variables affecting parasite distribution, as raising temperatures positively affect development, reproduction, and rate of transmission of both endo- and ectoparasites. In this context, it is generally accepted that, in mountains, parasite abundance decreases with elevation. However, empirical evidence on this topic is limited. In the present study, we analyzed the elevational variation of hemoparasites and ectoparasites of a lizard, Psammodromus algirus, along a 2,200-m elevational gradient in Sierra Nevada (SE Spain). As predicted, ectoparasite (mites, ticks, mosquitoes, and sandflies) abundance decreased with elevation. However, hemoparasite prevalence and intensity in the lizard augmented with altitude, showing a pattern contrary to their vectors (mites). We suggest that tolerance to hemoparasites may increase with elevation as a consequence of lizards at high altitudes taking advantage of increased body condition and food availability, and reduced oxidative stress. Moreover, lizards could have been selected for higher resistance against hemoparasites at lowlands (where higher rates of replication are expected), thus reducing hemoparasite prevalence and load. Our findings imply that, in a scenario of climate warming, populations of lizards at high elevation may face increased abundance of ectoparasites, accompanied with strong negative effects.

Locomotor performance is often key in animal fitness, and may be affected by habitat anthropization. This study compares locomotor performance of natterjack toads (Epidalea calamita), which move by intermittent runs, from a natural pine grove and surrounding agrosystems. The effects of sex, morphology and habitat on sprint speed and run rate (number of runs per metre) were assessed. Males were faster than females, and had longer limbs, but the latter trait only partially explained sex differences in sprint speed. Sprint speed was directly related to hindlimb length, but not to any of the other morphological traits measured. Thus, other factors, such as amplexus ability, seemingly shape longer forelimbs in males. Habitat did not affect sprint speed, but toads from the agrosystem habitat had a higher run rate, which could help increase vigilance or confound predators, probably related to habitat openness and/ or human presence. For a given speed, males used greater run rates than females, probably because males encounter predators more often and face higher predator pressure. Finally, a negative relationship between sprint speed and run rate suggests that slower toads tend to use short runs, which may improve vigilance or help to confuse predators, while faster toads tend to use long runs, probably for fast escape from predators.

In this work, I assess the effects of toe-clipping on sprint speed and run rate (number of runs per meter) of Epidalea calamita toads from agrosystem and their natural habitat. I videotaped toads in individual trials in a linear runway. Afterwards, I randomly assigned toads to two groups: control toads, which were not clipped, and experimental toads, which were immediately clipped the third toe in both hind limbs. One hour later, I videotaped a second trial. Controlling for sprint speed in the first trial, sprint speed in the second trial was similar in both groups. Likewise, run rate was not affected by toe-clipping. Sex and habitat had no effect on the consequences of toe-clipping on locomotor performance. These findings suggest that toe-clipping toads in the field should not increase predation risk or competitive disadvantage in searching for prey or mates in the short term.

[Introduction]: We aimed to assess the mid-Term type 2 diabetes mellitus recovery patterns in morbidly obese patients by comparing some relevant physiological parameters of patients of bariatric surgery between two types of surgical procedures: mixed (roux-en-Y gastric bypass and biliopancreatic diversion) and restrictive (sleeve gastrectomy)., [Material and methods]: This is a prospective and observational study of co-morbid, type 2 diabetes mellitus evolution in 49 morbidly obese patients: 37 underwent mixed surgery procedures and 12 a restrictive surgery procedure. We recorded weight, height, body mass index, and glycaemic, lipid, and nutritional blood parameters, prior to procedure, as well as six and twelve months post-operatively. In addition, we tested for differences in patient recovery and investigated predictive factors in diabetes remission., [Results]: Both glycaemic and lipid profiles diminished significantly to healthy levels by 6 and 12 months post intervention. Type 2 diabetes mellitus showed remission in more than 80% of patients of both types of surgical procedures, with no difference between them. Baseline body mass index, glycated haemoglobin, and insulin intake, among others, were shown to be valuable predictors of diabetes remission one year after the intervention., [Conclusions]: The choice of the type of surgical procedure did not significantly affect the remission rate of type 2 diabetes mellitus in morbidly obese patients.

Global amphibian decline is due to several factors: habitat loss, anthropization, pollution, emerging diseases, and global warming. Amphibians, with complex life cycles, are particularly susceptible to habitat alterations, and their survival may be impaired in anthropized habitats. Increased mortality is a well-known consequence of anthropization. Life-history theory predicts higher reproductive investment when mortality is increased. In this work, we compared age, body size, and different indicators of reproductive investment, as well as prey availability, in natterjack toads (Epidalea calamita) from agrosystems and adjacent natural pine groves in Southwestern Spain. Mean age was lower in agrosystems than in pine groves, possibly as a consequence of increased mortality due to agrosystem environmental stressors. Remarkably, agrosystem toads were larger despite being younger, suggesting accelerated growth rate. Although we detected no differences in prey availability between habitats, artificial irrigation could shorten aestivation in agrosystems, thus increasing energy trade. Moreover, agrosystem toads exhibited increased indicators of reproductive investment. In the light of lifehistory theory, agrosystem toads might compensate for lesser reproductive events due to shorter lives with a higher reproductive investment in each attempt. Our results show that agrosystems may alter demography, which may have complex consequences on both individual fitness and population stability

Mountains imply enormous environmental variation, with alpine habitats entailing harsh environments, especially for ectotherms such as lizards. This environmental variability also may imply variation in prey availability. However, little is known about how lizard trophic ecology varies with elevation. In this study, we analyze diet, prey availability, prey selection, and trophic niche width in the lacertid lizard Psammodromus algirus along a 2,200-m elevational gradient in the Sierra Nevada (SE Spain). The analysis of fecal samples has shown that Orthoptera, Formicidae, Hemiptera, Coleoptera, and Araneae are the main prey, although, according to their abundance in pitfall traps, Formicidae and Coleoptera are rejected by the lizard whereas Orthoptera, Hemiptera, and Araneae are preferred. Prey abundance and diversity increase with elevation and diet subtly varies along with the elevational gradient. The consumption of Coleoptera increases with elevation probably as a consequence of the lizard foraging more in open areas while basking. The electivity for Araneae increases with elevation. Araneae are rejected in the lowlands—where they are relatively abundant—whereas, at high elevation, this lizard positively selects them, despite they being less abundant. The lizard trophic niche width expands with elevation due to concomitant greater prey diversity and hence this lizard feeds on more prey types in highlands. Although no sex difference in diet has been found, the trophic niche is broader in females than males. As a whole, alpine lizards show a trophic niche similar to that found at lower elevations, suggesting that P. algirus is well adapted to the harsh environment found in alpine areas.

Chemical signals used in intraspecific communication are expected to evolve or to show phenotipic plasticity to maximize efficacy in the climatic conditions of a given environment. Elevational environmental gradients in mountains provide a good opportunity to test this hypothesis by examining variation in characteristics of signals in species found across different elevations with different climatic conditions. We analyzed by gas chromatography-mass spectrometry (GC-MS) the lipophilic fraction of the femoral gland secretions of male lizards Psammodromus algirus (Fam. Lacertidae) from six localities located along a 2200 m elevational gradient at Sierra Nevada Mountains (SE Spain). There was elevational clinal variation in climatic variables, number of femoral pores and in the relative proportions of some classes of compounds (i.e., ethyl esters of fatty acids, waxy esters, and aldehydes) but not others. We discuss how this variation would result in different physicochemical properties of the entire femoral secretion, which might help optimize the efficacy of chemical signals under the particular microclimatic conditions at each elevation.

Skeletochronology allows estimation of lizard age with a single capture (from a bone), making long-term monitoring unnecessary. Nevertheless, this method often involves the death of the animal to obtain the bone. We tested the reliability of skeletochronology of phalanges (which may be obtained without killing) by comparing the estimated age from femurs and humeri with the age estimated from phalanges. Our results show skeletochronology of phalanges is a reliable method to estimate age in lizards as cross-section readings from all bones studied presented a high correlation and repeatability regardless of the bone chosen. This approach provides an alternative to the killing of lizards for skeletochronology studies.