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José Martín - One of the best experts on this subject based on the ideXlab platform.
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experience may allow increasing accuracy of the innate chemosensory recognition of snake predators by iberian wall lizards
Behavioral Ecology and Sociobiology, 2015Co-Authors: José Martín, Jesus Ortega, Pilar LópezAbstract:Many animals can recognize chemical cues of predators and show defensive responses, but Antipredatory Behavior can be costly and should be modulated depending on the level of risk posed by each predatory species. Recognition ability may be innate, but it is not clear whether there might also be local adaptation to predation pressure levels or some learning component. We examined the chemosensory ability of naive and adult Iberian wall lizards, Podarcis hispanicus, to detect chemical cues of two closely related Coronella snake species in two localities within the same continuous population. Lizards in each locality are sympatric with only one of the two snake species. Our results showed an innate chemosensory discrimination of predatory snake cues, as both adult lizards and captive reared naive hatchlings, which had not had any previous experience with the snake cues, had short latencies to the first tongue-flick, increased tongue-flick responses, and active escape Behavior from the scent of either of the two snake species. Moreover, adult lizards, but not naive hatchlings, showed differential responses to the two different snake species, with higher responses to the snake species that is sympatric in each locality. This strongly suggests that there is a learning component acquired through previous lifetime experiences that may increase accuracy of the discrimination of the sympatric snake. Therefore, through learning of local conditions, lizards may modulate their innate Antipredatory responses to the risk level posed by each snake species.
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Conspecific alarm cues, but not predator cues alone, determine antipredator Behavior of larval southern marbled newts, Triturus pygmaeus
acta ethologica, 2012Co-Authors: Adega Gonzalo, Pilar López, Carlos Cabido, José MartínAbstract:Predation imposes selection on the ability of prey to recognize and respond to potential threats. Many prey species detect predators via chemoreception, particularly in aquatic environments. Also, chemical cues from injured prey are often perceived as an indication of predation risk. However, because Antipredatory Behavior can be costly, prey responses should depend on the current level of risk that each predator poses, which may depend on the type of chemical cues detected. We exposed larval newts, Triturus pygmaeus , to chemical cues from predator larval beetles or to alarm cues from conspecific larval newts and examined the Behavioral changes of larval newts. Results showed that larval newts reduced activity levels when conspecific alarm cues were present but not when the predator cues alone were present. These results might suggest that larval newts are unable to recognize predator chemicals. To avoid costs of unnecessary Antipredatory Behaviors, larval newts may benefit by avoiding only predators that represent a current high level of threat, showing only Antipredatory responses when they detect conspecific alarm cues indicating that an actual predatory attack has occurred.
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risk level of chemical cues determines retention of recognition of new predators in iberian green frog tadpoles
Behavioral Ecology and Sociobiology, 2010Co-Authors: Adega Gonzalo, Pilar López, José MartínAbstract:In aquatic environments, many prey rely on chemosensory information from injured (alarm cues) or stressed conspecifics (disturbance cues) to assess predation risk. Alarm cues are considered as a sign of higher risk than disturbance cues. These cues could be used by prey to learn potential new predators. In this study, we tested whether Iberian green frog tadpoles (Pelophylax perezi) exhibited antipredator responses to alarm and disturbance cues of conspecifics and whether tadpoles could associate new predators with alarm or disturbance cues. Tadpoles reduced their activity in the presence of disturbance cues, but only weakly when compared with their response to alarm cues. Also, tadpoles learned to recognize new predators from association with alarm or disturbance cues. However, the period of retention of the learned association was shorter for disturbance than alarm cues. Our results indicate that tadpoles are able to modify their Antipredatory Behavior according to (1) the degree of risk implied by the experimental cues (2) their previous experience of chemical cues of the predator.
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conspicuousness dependent Antipredatory Behavior may counteract coloration differences in iberian rock lizards
Behavioral Ecology, 2009Co-Authors: Carlos Cabido, Pilar López, Pedro Galan, José MartínAbstract:Sexual selection favors more conspicuous male displays, whereas natural selection (via predator pressure) favors less conspicuous displays. However, this trade-off might be altered if males with more conspicuous displays could compensate Behaviorally for their increased conspicuousness by acting more cautiously toward predators. The aim of this study was to explore in 2 species of Iberian rock lizards whether or not conspicuous coloration was associated with Antipredatory Behavior and whether conspicuousness-dependent regulation of Antipredatory Behavior existed. Our results suggested that male lizards may compensate for the negative effects of conspicuous sexual coloration on predation risk by modulating their Antipredatory Behavior (time inside refuges, false alarms, etc). We found that male Iberolacerta monticola, but not male Iberolacerta cyreni, compensated for the negative effects of blue lateral ocelli, which increased visual conspicuousness. However, male lizards did not compensate for relatively unexposed ventral spots. We also found that male I. monticola in better condition and with more blue lateral ocelli were shier, whereas male I. cyreni in better condition and with more ventral spots were bolder. These 2 lizard species live in habitats that differ in refuge availability and in the number of potential predators, which may promote differences in the trade-off between predation risk and social Behavior and may explain the observed interspecific differences in Antipredatory Behavior. This suggests that regulation of Antipredatory Behavior may also function as a condition-dependent cost promoting costly (honest) sexual signaling in some species. Copyright 2009, Oxford University Press.
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habitat deterioration affects Antipredatory Behavior body condition and parasite load of female psammodromus algirus lizards
Canadian Journal of Zoology, 2007Co-Authors: Luisa Amo, Pilar López, José MartínAbstract:Deforestation may increase predation risk for prey because it may make prey more conspicuous and limit the number of refuges suitable to avoid predators. Therefore, prey may need to increase the magnitude of escape responses. However, excessive Antipredatory effort might lead to a loss of body mass and a decrease in defense against parasites, with important consequences for short- and long-term fitness. We analyzed whether Psammodromus algirus (L., 1758) lizards that inhabit patches with different levels of deterioration of the vegetation within the same oak forest differed in relative abundance numbers, microhabitat use, Antipredatory strategies, and health state. Results showed lizards selected similar microhabitats regardless of the level of deterioration of the vegetation and relative abundance of lizards was similar in both areas. However, habitat deterioration seemed to increase predation risk, at least for females, because they were detected at longer distances in deteriorated areas. Females seemed...
Pilar López - One of the best experts on this subject based on the ideXlab platform.
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experience may allow increasing accuracy of the innate chemosensory recognition of snake predators by iberian wall lizards
Behavioral Ecology and Sociobiology, 2015Co-Authors: José Martín, Jesus Ortega, Pilar LópezAbstract:Many animals can recognize chemical cues of predators and show defensive responses, but Antipredatory Behavior can be costly and should be modulated depending on the level of risk posed by each predatory species. Recognition ability may be innate, but it is not clear whether there might also be local adaptation to predation pressure levels or some learning component. We examined the chemosensory ability of naive and adult Iberian wall lizards, Podarcis hispanicus, to detect chemical cues of two closely related Coronella snake species in two localities within the same continuous population. Lizards in each locality are sympatric with only one of the two snake species. Our results showed an innate chemosensory discrimination of predatory snake cues, as both adult lizards and captive reared naive hatchlings, which had not had any previous experience with the snake cues, had short latencies to the first tongue-flick, increased tongue-flick responses, and active escape Behavior from the scent of either of the two snake species. Moreover, adult lizards, but not naive hatchlings, showed differential responses to the two different snake species, with higher responses to the snake species that is sympatric in each locality. This strongly suggests that there is a learning component acquired through previous lifetime experiences that may increase accuracy of the discrimination of the sympatric snake. Therefore, through learning of local conditions, lizards may modulate their innate Antipredatory responses to the risk level posed by each snake species.
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Conspecific alarm cues, but not predator cues alone, determine antipredator Behavior of larval southern marbled newts, Triturus pygmaeus
acta ethologica, 2012Co-Authors: Adega Gonzalo, Pilar López, Carlos Cabido, José MartínAbstract:Predation imposes selection on the ability of prey to recognize and respond to potential threats. Many prey species detect predators via chemoreception, particularly in aquatic environments. Also, chemical cues from injured prey are often perceived as an indication of predation risk. However, because Antipredatory Behavior can be costly, prey responses should depend on the current level of risk that each predator poses, which may depend on the type of chemical cues detected. We exposed larval newts, Triturus pygmaeus , to chemical cues from predator larval beetles or to alarm cues from conspecific larval newts and examined the Behavioral changes of larval newts. Results showed that larval newts reduced activity levels when conspecific alarm cues were present but not when the predator cues alone were present. These results might suggest that larval newts are unable to recognize predator chemicals. To avoid costs of unnecessary Antipredatory Behaviors, larval newts may benefit by avoiding only predators that represent a current high level of threat, showing only Antipredatory responses when they detect conspecific alarm cues indicating that an actual predatory attack has occurred.
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risk level of chemical cues determines retention of recognition of new predators in iberian green frog tadpoles
Behavioral Ecology and Sociobiology, 2010Co-Authors: Adega Gonzalo, Pilar López, José MartínAbstract:In aquatic environments, many prey rely on chemosensory information from injured (alarm cues) or stressed conspecifics (disturbance cues) to assess predation risk. Alarm cues are considered as a sign of higher risk than disturbance cues. These cues could be used by prey to learn potential new predators. In this study, we tested whether Iberian green frog tadpoles (Pelophylax perezi) exhibited antipredator responses to alarm and disturbance cues of conspecifics and whether tadpoles could associate new predators with alarm or disturbance cues. Tadpoles reduced their activity in the presence of disturbance cues, but only weakly when compared with their response to alarm cues. Also, tadpoles learned to recognize new predators from association with alarm or disturbance cues. However, the period of retention of the learned association was shorter for disturbance than alarm cues. Our results indicate that tadpoles are able to modify their Antipredatory Behavior according to (1) the degree of risk implied by the experimental cues (2) their previous experience of chemical cues of the predator.
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conspicuousness dependent Antipredatory Behavior may counteract coloration differences in iberian rock lizards
Behavioral Ecology, 2009Co-Authors: Carlos Cabido, Pilar López, Pedro Galan, José MartínAbstract:Sexual selection favors more conspicuous male displays, whereas natural selection (via predator pressure) favors less conspicuous displays. However, this trade-off might be altered if males with more conspicuous displays could compensate Behaviorally for their increased conspicuousness by acting more cautiously toward predators. The aim of this study was to explore in 2 species of Iberian rock lizards whether or not conspicuous coloration was associated with Antipredatory Behavior and whether conspicuousness-dependent regulation of Antipredatory Behavior existed. Our results suggested that male lizards may compensate for the negative effects of conspicuous sexual coloration on predation risk by modulating their Antipredatory Behavior (time inside refuges, false alarms, etc). We found that male Iberolacerta monticola, but not male Iberolacerta cyreni, compensated for the negative effects of blue lateral ocelli, which increased visual conspicuousness. However, male lizards did not compensate for relatively unexposed ventral spots. We also found that male I. monticola in better condition and with more blue lateral ocelli were shier, whereas male I. cyreni in better condition and with more ventral spots were bolder. These 2 lizard species live in habitats that differ in refuge availability and in the number of potential predators, which may promote differences in the trade-off between predation risk and social Behavior and may explain the observed interspecific differences in Antipredatory Behavior. This suggests that regulation of Antipredatory Behavior may also function as a condition-dependent cost promoting costly (honest) sexual signaling in some species. Copyright 2009, Oxford University Press.
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habitat deterioration affects Antipredatory Behavior body condition and parasite load of female psammodromus algirus lizards
Canadian Journal of Zoology, 2007Co-Authors: Luisa Amo, Pilar López, José MartínAbstract:Deforestation may increase predation risk for prey because it may make prey more conspicuous and limit the number of refuges suitable to avoid predators. Therefore, prey may need to increase the magnitude of escape responses. However, excessive Antipredatory effort might lead to a loss of body mass and a decrease in defense against parasites, with important consequences for short- and long-term fitness. We analyzed whether Psammodromus algirus (L., 1758) lizards that inhabit patches with different levels of deterioration of the vegetation within the same oak forest differed in relative abundance numbers, microhabitat use, Antipredatory strategies, and health state. Results showed lizards selected similar microhabitats regardless of the level of deterioration of the vegetation and relative abundance of lizards was similar in both areas. However, habitat deterioration seemed to increase predation risk, at least for females, because they were detected at longer distances in deteriorated areas. Females seemed...
William E Cooper - One of the best experts on this subject based on the ideXlab platform.
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interactive effect of starting distance and approach speed on escape Behavior challenges theory
Behavioral Ecology, 2009Co-Authors: William E Cooper, Dror Hawlena, Valentin PerezmelladoAbstract:Escape theory predicts flight initiation distance (FID, predator-to-prey distance when escape begins) based on fixed functions relating costs and benefits of fleeing to distance between a prey and an approaching predator. Theory accurately predicts effects of costs for fixed functions and changes in functions due to changes in predator Behavior approach. Less obvious is how the effect of starting distance (predator-to-prey distance when approach begins) on FID can be explained when predator Behavior does not change during approach. We simulated predators to study effects of starting distance on FID in Balearic lizards (Podarcis lilfordi). Starting distance and approach speed affected FID interactively. It increased as starting distance increased during faster, but not slower, approaches. Because risk functions are considered fixed for a given approach speed, we must explain why FID varies with starting distance, why only for rapid approach, and how risk is assessed. Because prey approached slowly assess risk as small until the predator is very close, approach from greater distance has little effect on risk curves. Because continued rapid approach suggests that the predator has detected the prey and is attacking, not merely approaching, risk varies with starting distance. Theoretical difficulty in explaining the effect of starting distance on FID disappears if risk curves vary among starting distances at faster approach speeds, but each curve is fixed. This might occur if prey use a temporal rule of thumb assigning increasing risk as duration of rapid approach increases. Key words: Antipredatory Behavior, approach distance, escape, flight initiation distance, flush distance, starting distance. [Behav Ecol]
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universal optimization of flight initiation distance and habitat driven variation in escape tactics in a namibian lizard assemblage
Ethology, 2007Co-Authors: William E Cooper, Martin J. WhitingAbstract:Some aspects of escape predicted by theoretical models are intended to apply universally. For example, flight initiation distance (distance between an approaching predator and prey when escape begins) is predicted from predation risk and the costs of escaping. Escape tactics and refuge selection are not currently predicted by theoretical models, but are expected to vary with structural features of the habitat. One way of studying such variation is to compare aspects of Antipredatory Behavior among sympatric species that differ in habitat or microhabitat use. In an assemblage of lizards in northwestern Namibia, we conducted experiments to test predictions of escape theory for three risk factors in representatives of three families and observed escape tactics in additional species. As predicted by escape theory, flight initiation distance increased with directness of a predator’s approach and predator speed in Agama planiceps, Mabuya acutilabris, and Rhotropus boultoni, and with distance from refuge in M. acutilabris. As predicted by theory, the probability of entering refuge increased with risk in R. boultoni. All available data indicate that flight initiation distance and refuge entry by lizards conform to theoretical predictions. Escape tactics varied greatly as a function of habitat type: (1) arboreal species fled up and around trees and sometimes entered tree holes; (2) saxicolous species used rock crevices as refuges, but differed in tactics prior to entering refuges; and (3) terrestrial species fled into bushes or other vegetation, often to the far sides of them. Some M. acutilabris entered small animal burrows or buried themselves in sand beneath bushes. Escape tactics varied even among congeners in Mabuya, highlighting the important effect of habitat structure on them. Although habitat partitioning has traditionally been viewed as favoring species coexistence, an interesting by-product appears to be structuring of escape tactics in lizard communities.
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tradeoffs between courtship fighting and Antipredatory Behavior by a lizard eumeces laticeps
Behavioral Ecology and Sociobiology, 1999Co-Authors: William E CooperAbstract:Male fitness in many species depends strongly on social Behaviors needed to obtain fertilizations and prevent loss of fertilizations to other males, but courtship, copulation, and fighting may incur increased risk of predation. When demands for reproductive and Antipredatory Behaviors conflict, fitness may be maximized by accepting some degree of risk to enhance reproductive success. To examine such tradeoffs, I introduced tethered conspecific males or females to adult male broad-headed skinks, Eumeces laticeps, in the field and observed how close they allowed a simulated predator (me) to approach before fleeing, or their latency to approach an introduced female located at different distances from the predator. When conspecific males were introduced, isolated and mate-guarding males initiated agonistic Behaviors and permitted closer approach than control males, and mate-guarding males permitted closer approach than isolated males. When females were introduced, both isolated and mate-guarding males courted the introduced females and isolated males permitted closer approach than did mate-guarding males. These results for introduced males and females suggest that increasing risk was accepted when reproductive benefits were greater. Latency for isolated males to approach a conspecific female was greater when the predator was closer to the female, further suggesting sensitivity to predation risk during a reproductive opportunity. Relationships between reproductive and Antipredatory Behaviors have been studied much less than those between feeding and Antipredatory Behaviors, but this study indicates that animals balance increased risk of predation with the opportunity to perform several reproductively important Behaviors.
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threat factors affecting Antipredatory Behavior in the broad headed skink eumeces laticeps repeated approach change in predator path and predator s field of view
Copeia, 1997Co-Authors: William E CooperAbstract:Antipredatory Behavior can be studied from many perspectives, resulting in several distinct traditional foci in the saurological literature. Ethogrammatic efforts have produced extensive catalogs of defensive movement patterns (reviewed by Carpenter and Ferguson, 1977; Greene, 1988). A second very productive avenue has been experimental and observational study of costs, benefits, and correlates of defenses such as caudal autotomy and escape and avoidance Behaviors (e.g., Shine, 1980; Hertz et al., 1982; Arnold, 1988). In some cases, predictions about effects of specific risk factors have been tested (e.g., Bulova, 1994; Burger and Gochfeld, 1990; Brafia, 1993). Antipredatory Behavior has received the belated attention of optimality theorists only in recent years. Ydenberg and Dill (1986) developed a simple optimality model in which a prey's assessment of the degree of risk and the costs of fleeing determine how closely a prey allows a predator to approach before fleeing. Lima and Dill (1990) extended the optimality approach to several other components of predation risk. Clark (1994) emphasized that Antipredatory decisions should be made based on consequences for long-term expected fitness, but predation risk typically has been and is here considered only in the context of probability of mortality in the immediate future.
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Magnitude of food reward affects escape Behavior and acceptable risk in Balearic lizards, Podarcis lilfordi
2026Co-Authors: William E Cooper, Valentín Pérez-mellado, Dror HawlenaAbstract:During encounters with predators, prey must balance the degree of risk against the loss of fitness-enhancing benefits such as feeding and social activities. Most studies of tradeoffs between risk and cost of escaping have measured flight initiation distance and time to emerge from refuge, for which theory provides robustly supported predictions. Tradeoffs involving other aspects of encounters, including distance fled and time between escape and return to a food source, have received little theoretical or empirical attention. By adapting models of flight initiation distance and time between entry into refuge and emergence, we predict effects of predation risk and cost on distance fled and time to return to a source of benefit after fleeing. Acting as simulated predators that approached at a fixed speed, we conducted an experimental field study to test the hypotheses that flight initiation distance, distance fled, and time to return to food by Balearic lizards (Podarcis lilfordi) decrease with the presence and amount of insect food. Predictions of the models were strongly supported, including those for distance fled and return time, but predictions for other cost factors and predation risk factors remain to be tested. Copyright 2006.Antipredatory Behavior; approach distances; escape Behavior; flight initiation distance; Squamata
Dror Hawlena - One of the best experts on this subject based on the ideXlab platform.
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islet tameness escape Behavior and refuge use in populations of the balearic lizard podarcis lilfordi exposed to differing predation pressure
Canadian Journal of Zoology, 2009Co-Authors: Jr William E Cooper, Dror Hawlena, Valentin PerezmelladoAbstract:Prey often exhibit reduced escape Behavior on islands where predators are absent or scarce. Models of escape and refuge use predict that prey from populations having lower predation pressure have shortened flight initiation distance (FID; distance between a predator and a prey when escape begins), reduced distance fled and tendency to enter refuge, and shortened hiding time before emerging from refuge. By ourselves simulating approaching predators, we tested these predictions for two populations of the Balearic lizard, Podarcis lilfordi (Muller, 1927), on the islets of Rei (higher preda- tion pressure) and Aire (lower) adjacent to Menorca. FID, distance fled, and hiding time were shorter and probability of entering refuge was lower on Aire than on Rei, confirming all predictions. All effect sizes were large, indicating major dif- ferences in Antipredatory Behavior between islets. These findings are consistent with data for other lizards on FID and lim- ited data on distance fled and refuge entry. The effect of predation pressure on hiding time is a novel finding. Our results and those of previous studies suggest that relaxation of predation pressure leads to reduced natural selection for mainte- nance of Antipredatory Behavior at all stages of predator-prey interactions over a relatively short time span.
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interactive effect of starting distance and approach speed on escape Behavior challenges theory
Behavioral Ecology, 2009Co-Authors: William E Cooper, Dror Hawlena, Valentin PerezmelladoAbstract:Escape theory predicts flight initiation distance (FID, predator-to-prey distance when escape begins) based on fixed functions relating costs and benefits of fleeing to distance between a prey and an approaching predator. Theory accurately predicts effects of costs for fixed functions and changes in functions due to changes in predator Behavior approach. Less obvious is how the effect of starting distance (predator-to-prey distance when approach begins) on FID can be explained when predator Behavior does not change during approach. We simulated predators to study effects of starting distance on FID in Balearic lizards (Podarcis lilfordi). Starting distance and approach speed affected FID interactively. It increased as starting distance increased during faster, but not slower, approaches. Because risk functions are considered fixed for a given approach speed, we must explain why FID varies with starting distance, why only for rapid approach, and how risk is assessed. Because prey approached slowly assess risk as small until the predator is very close, approach from greater distance has little effect on risk curves. Because continued rapid approach suggests that the predator has detected the prey and is attacking, not merely approaching, risk varies with starting distance. Theoretical difficulty in explaining the effect of starting distance on FID disappears if risk curves vary among starting distances at faster approach speeds, but each curve is fixed. This might occur if prey use a temporal rule of thumb assigning increasing risk as duration of rapid approach increases. Key words: Antipredatory Behavior, approach distance, escape, flight initiation distance, flush distance, starting distance. [Behav Ecol]
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Blue tail and striped body: why do lizards change their infant costume when growing up? Behav
2006Co-Authors: Dror Hawlena, Rami Boochnik, Zvika A Abramsky, Amos BouskilaaAbstract:Ontogenetic changes in color and pattern that are not directly related to reproduction are very common yet remain a poorly understood phenomenon. One example is conspicuous colors in the tails of fish, amphibians, and reptiles that fade out later in life. We suggest a novel hypothesis: conspicuous tail colors that appear only in juveniles compensate for an increased activity level, deflecting imminent attacks to the tail. We observed blue-tailed, newly hatched lizards (Acanthodactylus beershebensis) in the field and compared 5 Behavioral parameters with those of older individuals that had already lost their neonate coloration. In addition, we explored whether tail displays, often assumed to direct a predator’s attention to the tail, disappear with the color change. Striped blue-tailed hatchlings foraged more actively than 3-week-old juveniles, spent a longer time in open microhabitats, and performed deflective tail displays. In comparison, 2 other lacertids that do not undergo ontogenetic change did not switch to safer foraging when growing up. The results suggest that activity alteration may be a major factor affecting the ontogenetic color and pattern change. Active lizards that forage in open habitats increase their probability of attack by ambush predators. Conspicuous colors and deflection displays may shift attacks to the expendable tail, increasing the prey’s overall probability of surviving attacks. The persistence of both striped body pattern and blue tail fits the active foraging period of neonates and hence may be appropriate for other species that display a conspicuous tail accompanied by a striped pattern. Key words: Acanthodactylus beershebensis, Antipredatory Behavior, autotomy, foraging activity, ontogeny. [Behav Ecol 17:889–896 (2006)] Many vertebrate species belonging to different taxa showage-related (ontogenetic), directional changes in color
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Magnitude of food reward affects escape Behavior and acceptable risk in Balearic lizards, Podarcis lilfordi
2026Co-Authors: William E Cooper, Valentín Pérez-mellado, Dror HawlenaAbstract:During encounters with predators, prey must balance the degree of risk against the loss of fitness-enhancing benefits such as feeding and social activities. Most studies of tradeoffs between risk and cost of escaping have measured flight initiation distance and time to emerge from refuge, for which theory provides robustly supported predictions. Tradeoffs involving other aspects of encounters, including distance fled and time between escape and return to a food source, have received little theoretical or empirical attention. By adapting models of flight initiation distance and time between entry into refuge and emergence, we predict effects of predation risk and cost on distance fled and time to return to a source of benefit after fleeing. Acting as simulated predators that approached at a fixed speed, we conducted an experimental field study to test the hypotheses that flight initiation distance, distance fled, and time to return to food by Balearic lizards (Podarcis lilfordi) decrease with the presence and amount of insect food. Predictions of the models were strongly supported, including those for distance fled and return time, but predictions for other cost factors and predation risk factors remain to be tested. Copyright 2006.Antipredatory Behavior; approach distances; escape Behavior; flight initiation distance; Squamata
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Blue tail and striped body: why do lizards change their infant costume when growing up?
2026Co-Authors: Dror Hawlena, Zvika Abramsky, Rami Boochnik, Amos BouskilaAbstract:Ontogenetic changes in color and pattern that are not directly related to reproduction are very common yet remain a poorly understood phenomenon. One example is conspicuous colors in the tails of fish, amphibians, and reptiles that fade out later in life. We suggest a novel hypothesis: conspicuous tail colors that appear only in juveniles compensate for an increased activity level, deflecting imminent attacks to the tail. We observed blue-tailed, newly hatched lizards (Acanthodactylus beershebensis) in the field and compared 5 Behavioral parameters with those of older individuals that had already lost their neonate coloration. In addition, we explored whether tail displays, often assumed to direct a predator's attention to the tail, disappear with the color change. Striped blue-tailed hatchlings foraged more actively than 3-week-old juveniles, spent a longer time in open microhabitats, and performed deflective tail displays. In comparison, 2 other lacertids that do not undergo ontogenetic change did not switch to safer foraging when growing up. The results suggest that activity alteration may be a major factor affecting the ontogenetic color and pattern change. Active lizards that forage in open habitats increase their probability of attack by ambush predators. Conspicuous colors and deflection displays may shift attacks to the expendable tail, increasing the prey's overall probability of surviving attacks. The persistence of both striped body pattern and blue tail fits the active foraging period of neonates and hence may be appropriate for other species that display a conspicuous tail accompanied by a striped pattern. Copyright 2006.Acanthodactylus beershebensis; Antipredatory Behavior; autotomy; foraging activity; ontogeny
Valentin Perezmellado - One of the best experts on this subject based on the ideXlab platform.
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islet tameness escape Behavior and refuge use in populations of the balearic lizard podarcis lilfordi exposed to differing predation pressure
Canadian Journal of Zoology, 2009Co-Authors: Jr William E Cooper, Dror Hawlena, Valentin PerezmelladoAbstract:Prey often exhibit reduced escape Behavior on islands where predators are absent or scarce. Models of escape and refuge use predict that prey from populations having lower predation pressure have shortened flight initiation distance (FID; distance between a predator and a prey when escape begins), reduced distance fled and tendency to enter refuge, and shortened hiding time before emerging from refuge. By ourselves simulating approaching predators, we tested these predictions for two populations of the Balearic lizard, Podarcis lilfordi (Muller, 1927), on the islets of Rei (higher preda- tion pressure) and Aire (lower) adjacent to Menorca. FID, distance fled, and hiding time were shorter and probability of entering refuge was lower on Aire than on Rei, confirming all predictions. All effect sizes were large, indicating major dif- ferences in Antipredatory Behavior between islets. These findings are consistent with data for other lizards on FID and lim- ited data on distance fled and refuge entry. The effect of predation pressure on hiding time is a novel finding. Our results and those of previous studies suggest that relaxation of predation pressure leads to reduced natural selection for mainte- nance of Antipredatory Behavior at all stages of predator-prey interactions over a relatively short time span.
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interactive effect of starting distance and approach speed on escape Behavior challenges theory
Behavioral Ecology, 2009Co-Authors: William E Cooper, Dror Hawlena, Valentin PerezmelladoAbstract:Escape theory predicts flight initiation distance (FID, predator-to-prey distance when escape begins) based on fixed functions relating costs and benefits of fleeing to distance between a prey and an approaching predator. Theory accurately predicts effects of costs for fixed functions and changes in functions due to changes in predator Behavior approach. Less obvious is how the effect of starting distance (predator-to-prey distance when approach begins) on FID can be explained when predator Behavior does not change during approach. We simulated predators to study effects of starting distance on FID in Balearic lizards (Podarcis lilfordi). Starting distance and approach speed affected FID interactively. It increased as starting distance increased during faster, but not slower, approaches. Because risk functions are considered fixed for a given approach speed, we must explain why FID varies with starting distance, why only for rapid approach, and how risk is assessed. Because prey approached slowly assess risk as small until the predator is very close, approach from greater distance has little effect on risk curves. Because continued rapid approach suggests that the predator has detected the prey and is attacking, not merely approaching, risk varies with starting distance. Theoretical difficulty in explaining the effect of starting distance on FID disappears if risk curves vary among starting distances at faster approach speeds, but each curve is fixed. This might occur if prey use a temporal rule of thumb assigning increasing risk as duration of rapid approach increases. Key words: Antipredatory Behavior, approach distance, escape, flight initiation distance, flush distance, starting distance. [Behav Ecol]