The Experts below are selected from a list of 147 Experts worldwide ranked by ideXlab platform
Richard Shine - One of the best experts on this subject based on the ideXlab platform.
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activity patterns and movements of free ranging bluetongue lizards Tiliqua scincoides intermedia and Tiliqua multifasciata in the australian wet dry tropics
Journal of Herpetology, 2014Co-Authors: Samantha J Pricerees, Gregory P. Brown, Richard ShineAbstract:Abstract We used GPS-based radiotelemetry to quantify diel activity patterns and movements by two species of large scincid lizards in the Australian wet-dry tropics. From an average of 63 days tracking of 54 Northern Bluetongues (Tiliqua scincoides intermedia) and 42 days tracking of 8 Centralian Bluetongues (Tiliqua multifasciata), we obtained 53,801 and 8,139 data points, respectively, on lizard locations over a 13-month period. Lizard species, sex, and study site had relatively little effect on distances moved, at both daily and hourly levels. However, Northern Bluetongues moved further per day than did Centralian Bluetongues at a site where they were sympatric. Most movements were <20 m, with longer movements (dispersal between core areas within the wider home range) occurring primarily during midmorning and late afternoon. The only major effect of ambient temperatures on lizard activity patterns likely was that midday movements were precluded by the risk of overheating; at all other times of the day ...
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reducing the impact of a toxic invader by inducing taste aversion in an imperilled native reptile predator
Animal Conservation, 2013Co-Authors: Samantha J Pricerees, Jonathan K Webb, Richard ShineAbstract:It is virtually impossible to eradicate invasive organisms once they have spread widely, and even low densities of invaders may have devastating impacts. We need to explore alternative management options that accept the inevitability of encounters between alien and native taxa, but reduce the negative consequences of those encounters. Conditioned taste aversion (CTA) is one approach that offers promise in this respect. The spread of the invasive cane toad Rhinella marina across northern Australia is devastating populations of predators such as the blue-tongued skink Tiliqua scincoides intermedia. Predators unable to tolerate the toads' powerful bufadienolide chemical defences are likely to die if they ingest a toad. We trained field-caught skinks to avoid eating cane toad flesh, by offering them toad sausages laced with a nausea-inducing chemical (lithium chloride). These individuals (and controls) were then released and radio-tracked as toads arrived at our study site in north-western Australia. Skinks that regurgitated after consuming the toad sausage survived after release, whereas most untrained animals were fatally poisoned by toad ingestion. Even if we cannot eradicate invasive cane toads, we can ameliorate their ecological impact by CTA training of vulnerable predators.
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habitat selection by bluetongue lizards Tiliqua scincidae in tropical australia a study using gps telemetry
Animal Biotelemetry, 2013Co-Authors: Samantha J Pricerees, Gregory P. Brown, Richard ShineAbstract:Emerging global positioning system (GPS) technologies can clarify movement patterns of free-ranging animals in far more detail than has been possible with previous methods. We conducted long-term (mean, 65 days; maximum, 221 days) GPS radio-tracking of 41 northern bluetongue lizards (Tiliqua scincoides intermedia) and 8 centralian bluetongue lizards (T. multifasciata) at two study sites in northwestern Australia, close to the border between Western Australia and the Northern Territory. Individuals of both species spent long periods within small and distinctive habitat patches, interspersed with longer directional relocations from one patch to the next. Our sampling showed that these patches of core activity differed significantly from the surrounding landscape in several respects. The patches provided relatively shaded, cool, and damp conditions, with higher grass and more leaf-litter cover. The location of these patches in the landscape is probably determined by drainage patterns, soil moisture-holding ability, and stochastic recruitment of shade trees. These scattered patches provide a critically important habitat for lizards (and probably, other taxa) within this hot dry landscape. Future conservation and management strategies need to prioritize the retention of such sites, at a spatial scale that allows animals to move between them.
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Road transect surveys do not reveal any consistent effects of a toxic invasive species on tropical reptiles
Biological Invasions, 2013Co-Authors: Gregory P. Brown, Matthew J. Greenlees, Benjamin L. Phillips, Richard ShineAbstract:Effects of perturbations to wildlife often are measured by changes in rates of encounter with animals during standardised surveys, such as along roads. Previous work has predicted that the invasion of toxic cane toads ( Rhinella marina ) through the Australian tropics will cause massive mortality of anuran-eating snakes, and influence abundances of other native species. We surveyed three adjacent road transects for nocturnal snakes and lizards, beginning shortly before toads arrived at this site near Darwin, in the Northern Territory. In the wet-seasons of four successive years, we conducted surveys on 591 nights; on 302 of these nights, all three transects were surveyed. We recorded 8,880 live cane toads and 3,365 live reptiles. Toad numbers increased over time on all three transects but encounters with 13 species of native reptiles varied inconsistently. Eight of the 13 species of native reptile showed no significant change in encounter rates following the arrival of toads. Of the five species that did change in encounter rates, only one taxon (the bluetongue skink, Tiliqua scincoides intermedia ) declined across all three transects. Encounter rates of the other four species often increased on at least one transect but decreased on at least one other. Thus, either the impact of cane toads on counts of reptiles differed between nearby sites, or (more likely) other factors had more influence on reptile numbers. A consistent decrease in reptile numbers on the busiest road over the study period suggests that local snake populations were affected more by road-kill than by invasive toads. Without spatial replication, this decrease could have been interpreted as an impact of toad invasion.
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school for skinks can conditioned taste aversion enable bluetongue lizards Tiliqua scincoides to avoid toxic cane toads rhinella marina as prey
Ethology, 2011Co-Authors: Samantha J Pricerees, Jonathan K Webb, Richard ShineAbstract:The invasion of cane toads (Rhinella marina) through Australia imperils native predators that are killed if they consume these toxic anurans. The magnitude of impact depends upon the predators’ capacity for aversion learning: toad impact is lower if predators can learn not to attack toads. In laboratory trials, we assessed whether bluetongue lizards (Tiliqua scincoides) ‐ a species under severe threat from toads ‐ are capable of learned taste aversion and whether we can facilitate that learning by exposing lizards to toad tissue combined with a nausea-inducing chemical (lithium chloride). Captive bluetongues rapidly learned to avoid the ‘unpalatable’ food. Taste aversion also developed (albeit less strongly) in response to meals of minced cane toad alone. Our data suggest that taste aversion learning may help bluetongue lizards survive the onslaught of cane toads, but that many encounters will be fatal because the toxin content of toads is so high relative to lizard tolerance of those toxins. Thus, baiting with nausea-inducing (but non-lethal) toad products might provide a feasible management option to reduce the impact of cane toad invasion on these native predators.
Samantha J Pricerees - One of the best experts on this subject based on the ideXlab platform.
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activity patterns and movements of free ranging bluetongue lizards Tiliqua scincoides intermedia and Tiliqua multifasciata in the australian wet dry tropics
Journal of Herpetology, 2014Co-Authors: Samantha J Pricerees, Gregory P. Brown, Richard ShineAbstract:Abstract We used GPS-based radiotelemetry to quantify diel activity patterns and movements by two species of large scincid lizards in the Australian wet-dry tropics. From an average of 63 days tracking of 54 Northern Bluetongues (Tiliqua scincoides intermedia) and 42 days tracking of 8 Centralian Bluetongues (Tiliqua multifasciata), we obtained 53,801 and 8,139 data points, respectively, on lizard locations over a 13-month period. Lizard species, sex, and study site had relatively little effect on distances moved, at both daily and hourly levels. However, Northern Bluetongues moved further per day than did Centralian Bluetongues at a site where they were sympatric. Most movements were <20 m, with longer movements (dispersal between core areas within the wider home range) occurring primarily during midmorning and late afternoon. The only major effect of ambient temperatures on lizard activity patterns likely was that midday movements were precluded by the risk of overheating; at all other times of the day ...
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reducing the impact of a toxic invader by inducing taste aversion in an imperilled native reptile predator
Animal Conservation, 2013Co-Authors: Samantha J Pricerees, Jonathan K Webb, Richard ShineAbstract:It is virtually impossible to eradicate invasive organisms once they have spread widely, and even low densities of invaders may have devastating impacts. We need to explore alternative management options that accept the inevitability of encounters between alien and native taxa, but reduce the negative consequences of those encounters. Conditioned taste aversion (CTA) is one approach that offers promise in this respect. The spread of the invasive cane toad Rhinella marina across northern Australia is devastating populations of predators such as the blue-tongued skink Tiliqua scincoides intermedia. Predators unable to tolerate the toads' powerful bufadienolide chemical defences are likely to die if they ingest a toad. We trained field-caught skinks to avoid eating cane toad flesh, by offering them toad sausages laced with a nausea-inducing chemical (lithium chloride). These individuals (and controls) were then released and radio-tracked as toads arrived at our study site in north-western Australia. Skinks that regurgitated after consuming the toad sausage survived after release, whereas most untrained animals were fatally poisoned by toad ingestion. Even if we cannot eradicate invasive cane toads, we can ameliorate their ecological impact by CTA training of vulnerable predators.
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habitat selection by bluetongue lizards Tiliqua scincidae in tropical australia a study using gps telemetry
Animal Biotelemetry, 2013Co-Authors: Samantha J Pricerees, Gregory P. Brown, Richard ShineAbstract:Emerging global positioning system (GPS) technologies can clarify movement patterns of free-ranging animals in far more detail than has been possible with previous methods. We conducted long-term (mean, 65 days; maximum, 221 days) GPS radio-tracking of 41 northern bluetongue lizards (Tiliqua scincoides intermedia) and 8 centralian bluetongue lizards (T. multifasciata) at two study sites in northwestern Australia, close to the border between Western Australia and the Northern Territory. Individuals of both species spent long periods within small and distinctive habitat patches, interspersed with longer directional relocations from one patch to the next. Our sampling showed that these patches of core activity differed significantly from the surrounding landscape in several respects. The patches provided relatively shaded, cool, and damp conditions, with higher grass and more leaf-litter cover. The location of these patches in the landscape is probably determined by drainage patterns, soil moisture-holding ability, and stochastic recruitment of shade trees. These scattered patches provide a critically important habitat for lizards (and probably, other taxa) within this hot dry landscape. Future conservation and management strategies need to prioritize the retention of such sites, at a spatial scale that allows animals to move between them.
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school for skinks can conditioned taste aversion enable bluetongue lizards Tiliqua scincoides to avoid toxic cane toads rhinella marina as prey
Ethology, 2011Co-Authors: Samantha J Pricerees, Jonathan K Webb, Richard ShineAbstract:The invasion of cane toads (Rhinella marina) through Australia imperils native predators that are killed if they consume these toxic anurans. The magnitude of impact depends upon the predators’ capacity for aversion learning: toad impact is lower if predators can learn not to attack toads. In laboratory trials, we assessed whether bluetongue lizards (Tiliqua scincoides) ‐ a species under severe threat from toads ‐ are capable of learned taste aversion and whether we can facilitate that learning by exposing lizards to toad tissue combined with a nausea-inducing chemical (lithium chloride). Captive bluetongues rapidly learned to avoid the ‘unpalatable’ food. Taste aversion also developed (albeit less strongly) in response to meals of minced cane toad alone. Our data suggest that taste aversion learning may help bluetongue lizards survive the onslaught of cane toads, but that many encounters will be fatal because the toxin content of toads is so high relative to lizard tolerance of those toxins. Thus, baiting with nausea-inducing (but non-lethal) toad products might provide a feasible management option to reduce the impact of cane toad invasion on these native predators.
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predation on toxic cane toads bufo marinus may imperil bluetongue lizards Tiliqua scincoides intermedia scincidae in tropical australia
Wildlife Research, 2010Co-Authors: Samantha J Pricerees, Gregory P. Brown, Richard ShineAbstract:Context. Detecting ecological impacts of invasive species can be extremely difficult. Even major population declines may be undetectable without extensive long-term data if the affected taxon is rare and/or difficult to census, and exhibits stochastic variation in abundance as a result of other factors. Our data suggest such a situation in an iconic Australian reptile species, the bluetongue lizard. Originally restricted to Central and South America, cane toads (Bufo marinus) are rapidly spreading through tropical Australia. Most native predators have no evolutionary history of exposure to the toads’ distinctive chemical defences (bufadienolides), and many varanid lizards, elapid snakes, crocodiles and marsupials have been killed when they have attempted to consume toads. Aims. Scincid lizards have not been considered vulnerable to toad invasion; however, one lineage (the bluetongues, genus Tiliqua) consists of large omnivores that may be affected. Our field and laboratory research aimed to elucidate this concern. Methods. Nightly surveys for bluetongue lizards (Tiliqua scincoides intermedia) and cane toads were conducted along two adjacent roadways on the Adelaide River floodplain of the Northern Territory. Scent discrimination trials in the laboratory assessed lizard responses to chemical cues from three food types (native frogs, cane toads and ‘preferred foods’) by counting tongue-flicks and biting elicited by cotton swabs. A subset of lizards was presented with live toads. Key results. Numbers of bluetongues encountered during standardised field surveys in the Darwin region declined soon after toads arrived, and we have not recorded a single lizard for the last 20 months. In the laboratory, foraging responses of bluetongues were as intense to cane-toad scent as to the scent of native frogs, and many of the lizards we tested attempted to consume toads, and were poisoned as a result. Conclusions and implications. The population decline of bluetongues in this region appears to have been the direct result of fatal ingestion of toxic cane toads. Our studies thus add a scincid lizard species to the list of native Australian predators imperilled by cane-toad invasion, and point to the difficulty of detecting invader impact even for an iconic species in a system subject to detailed survey work.
Gregory P. Brown - One of the best experts on this subject based on the ideXlab platform.
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activity patterns and movements of free ranging bluetongue lizards Tiliqua scincoides intermedia and Tiliqua multifasciata in the australian wet dry tropics
Journal of Herpetology, 2014Co-Authors: Samantha J Pricerees, Gregory P. Brown, Richard ShineAbstract:Abstract We used GPS-based radiotelemetry to quantify diel activity patterns and movements by two species of large scincid lizards in the Australian wet-dry tropics. From an average of 63 days tracking of 54 Northern Bluetongues (Tiliqua scincoides intermedia) and 42 days tracking of 8 Centralian Bluetongues (Tiliqua multifasciata), we obtained 53,801 and 8,139 data points, respectively, on lizard locations over a 13-month period. Lizard species, sex, and study site had relatively little effect on distances moved, at both daily and hourly levels. However, Northern Bluetongues moved further per day than did Centralian Bluetongues at a site where they were sympatric. Most movements were <20 m, with longer movements (dispersal between core areas within the wider home range) occurring primarily during midmorning and late afternoon. The only major effect of ambient temperatures on lizard activity patterns likely was that midday movements were precluded by the risk of overheating; at all other times of the day ...
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habitat selection by bluetongue lizards Tiliqua scincidae in tropical australia a study using gps telemetry
Animal Biotelemetry, 2013Co-Authors: Samantha J Pricerees, Gregory P. Brown, Richard ShineAbstract:Emerging global positioning system (GPS) technologies can clarify movement patterns of free-ranging animals in far more detail than has been possible with previous methods. We conducted long-term (mean, 65 days; maximum, 221 days) GPS radio-tracking of 41 northern bluetongue lizards (Tiliqua scincoides intermedia) and 8 centralian bluetongue lizards (T. multifasciata) at two study sites in northwestern Australia, close to the border between Western Australia and the Northern Territory. Individuals of both species spent long periods within small and distinctive habitat patches, interspersed with longer directional relocations from one patch to the next. Our sampling showed that these patches of core activity differed significantly from the surrounding landscape in several respects. The patches provided relatively shaded, cool, and damp conditions, with higher grass and more leaf-litter cover. The location of these patches in the landscape is probably determined by drainage patterns, soil moisture-holding ability, and stochastic recruitment of shade trees. These scattered patches provide a critically important habitat for lizards (and probably, other taxa) within this hot dry landscape. Future conservation and management strategies need to prioritize the retention of such sites, at a spatial scale that allows animals to move between them.
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Road transect surveys do not reveal any consistent effects of a toxic invasive species on tropical reptiles
Biological Invasions, 2013Co-Authors: Gregory P. Brown, Matthew J. Greenlees, Benjamin L. Phillips, Richard ShineAbstract:Effects of perturbations to wildlife often are measured by changes in rates of encounter with animals during standardised surveys, such as along roads. Previous work has predicted that the invasion of toxic cane toads ( Rhinella marina ) through the Australian tropics will cause massive mortality of anuran-eating snakes, and influence abundances of other native species. We surveyed three adjacent road transects for nocturnal snakes and lizards, beginning shortly before toads arrived at this site near Darwin, in the Northern Territory. In the wet-seasons of four successive years, we conducted surveys on 591 nights; on 302 of these nights, all three transects were surveyed. We recorded 8,880 live cane toads and 3,365 live reptiles. Toad numbers increased over time on all three transects but encounters with 13 species of native reptiles varied inconsistently. Eight of the 13 species of native reptile showed no significant change in encounter rates following the arrival of toads. Of the five species that did change in encounter rates, only one taxon (the bluetongue skink, Tiliqua scincoides intermedia ) declined across all three transects. Encounter rates of the other four species often increased on at least one transect but decreased on at least one other. Thus, either the impact of cane toads on counts of reptiles differed between nearby sites, or (more likely) other factors had more influence on reptile numbers. A consistent decrease in reptile numbers on the busiest road over the study period suggests that local snake populations were affected more by road-kill than by invasive toads. Without spatial replication, this decrease could have been interpreted as an impact of toad invasion.
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predation on toxic cane toads bufo marinus may imperil bluetongue lizards Tiliqua scincoides intermedia scincidae in tropical australia
Wildlife Research, 2010Co-Authors: Samantha J Pricerees, Gregory P. Brown, Richard ShineAbstract:Context. Detecting ecological impacts of invasive species can be extremely difficult. Even major population declines may be undetectable without extensive long-term data if the affected taxon is rare and/or difficult to census, and exhibits stochastic variation in abundance as a result of other factors. Our data suggest such a situation in an iconic Australian reptile species, the bluetongue lizard. Originally restricted to Central and South America, cane toads (Bufo marinus) are rapidly spreading through tropical Australia. Most native predators have no evolutionary history of exposure to the toads’ distinctive chemical defences (bufadienolides), and many varanid lizards, elapid snakes, crocodiles and marsupials have been killed when they have attempted to consume toads. Aims. Scincid lizards have not been considered vulnerable to toad invasion; however, one lineage (the bluetongues, genus Tiliqua) consists of large omnivores that may be affected. Our field and laboratory research aimed to elucidate this concern. Methods. Nightly surveys for bluetongue lizards (Tiliqua scincoides intermedia) and cane toads were conducted along two adjacent roadways on the Adelaide River floodplain of the Northern Territory. Scent discrimination trials in the laboratory assessed lizard responses to chemical cues from three food types (native frogs, cane toads and ‘preferred foods’) by counting tongue-flicks and biting elicited by cotton swabs. A subset of lizards was presented with live toads. Key results. Numbers of bluetongues encountered during standardised field surveys in the Darwin region declined soon after toads arrived, and we have not recorded a single lizard for the last 20 months. In the laboratory, foraging responses of bluetongues were as intense to cane-toad scent as to the scent of native frogs, and many of the lizards we tested attempted to consume toads, and were poisoned as a result. Conclusions and implications. The population decline of bluetongues in this region appears to have been the direct result of fatal ingestion of toxic cane toads. Our studies thus add a scincid lizard species to the list of native Australian predators imperilled by cane-toad invasion, and point to the difficulty of detecting invader impact even for an iconic species in a system subject to detailed survey work.
Jonathan K Webb - One of the best experts on this subject based on the ideXlab platform.
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reducing the impact of a toxic invader by inducing taste aversion in an imperilled native reptile predator
Animal Conservation, 2013Co-Authors: Samantha J Pricerees, Jonathan K Webb, Richard ShineAbstract:It is virtually impossible to eradicate invasive organisms once they have spread widely, and even low densities of invaders may have devastating impacts. We need to explore alternative management options that accept the inevitability of encounters between alien and native taxa, but reduce the negative consequences of those encounters. Conditioned taste aversion (CTA) is one approach that offers promise in this respect. The spread of the invasive cane toad Rhinella marina across northern Australia is devastating populations of predators such as the blue-tongued skink Tiliqua scincoides intermedia. Predators unable to tolerate the toads' powerful bufadienolide chemical defences are likely to die if they ingest a toad. We trained field-caught skinks to avoid eating cane toad flesh, by offering them toad sausages laced with a nausea-inducing chemical (lithium chloride). These individuals (and controls) were then released and radio-tracked as toads arrived at our study site in north-western Australia. Skinks that regurgitated after consuming the toad sausage survived after release, whereas most untrained animals were fatally poisoned by toad ingestion. Even if we cannot eradicate invasive cane toads, we can ameliorate their ecological impact by CTA training of vulnerable predators.
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school for skinks can conditioned taste aversion enable bluetongue lizards Tiliqua scincoides to avoid toxic cane toads rhinella marina as prey
Ethology, 2011Co-Authors: Samantha J Pricerees, Jonathan K Webb, Richard ShineAbstract:The invasion of cane toads (Rhinella marina) through Australia imperils native predators that are killed if they consume these toxic anurans. The magnitude of impact depends upon the predators’ capacity for aversion learning: toad impact is lower if predators can learn not to attack toads. In laboratory trials, we assessed whether bluetongue lizards (Tiliqua scincoides) ‐ a species under severe threat from toads ‐ are capable of learned taste aversion and whether we can facilitate that learning by exposing lizards to toad tissue combined with a nausea-inducing chemical (lithium chloride). Captive bluetongues rapidly learned to avoid the ‘unpalatable’ food. Taste aversion also developed (albeit less strongly) in response to meals of minced cane toad alone. Our data suggest that taste aversion learning may help bluetongue lizards survive the onslaught of cane toads, but that many encounters will be fatal because the toxin content of toads is so high relative to lizard tolerance of those toxins. Thus, baiting with nausea-inducing (but non-lethal) toad products might provide a feasible management option to reduce the impact of cane toad invasion on these native predators.
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Energetics of bluetongue lizards (Tiliqua scincoides) in a seasonal tropical environment
Oecologia, 2003Co-Authors: Keith A. Christian, Jonathan K Webb, Timothy J. SchultzAbstract:We studied the physiological ecology of bluetongue lizards ( Tiliqua scincoides ) on the Adelaide River floodplain in tropical Australia to determine the seasonal patterns of energy expenditure and to determine the mechanisms by which seasonal differences were achieved. Field metabolic rates (FMR) were significantly lower in the dry season (37.6 kJ kg^−1 day^−1; n =9) than in the wet (127.3 kJ kg^−1 day^−1; n =7). Water flux was also lower in the dry season (6.8 ml kg^−1 day^−1; n =9) than in the wet (39.4 ml kg^−1 day^−1; n =7). Measurements of body temperatures ( T _b) and movements of free-ranging animals, and standard metabolic rate (SMR) of recently caught animals, allowed a detailed analysis of energy budgets for wet and dry seasons. In the dry, bluetongue lizards expended 90 kJ kg^−1 day^−1 less energy than in the wet season. Unlike some other lizards of the wet-dry tropics, SMR did not differ between seasons. About 5% of the seasonal difference in FMR was due to lower night time T _b during the dry season, and about 7% was due to lower diurnal T _b. The remaining 88% of the decrease in energy expended in the dry season was due to a substantial decrease in other costs that may include reproduction, growth, digestion and activity. If we assume the animals fed daily and the costs of digestion are taken into account, the estimates are: 14% of the savings result from lower T _b at night, 20% from lower T _b in the day, and 66% result from decreased activity. It is therefore apparent that, unlike some agamid and varanid lizards that use a combination of behavioural and physiological mechanisms to conserve energy when food and water are limited, bluetongue lizards primarily use behavioural mechanisms to achieve a dramatic reduction in energy expenditure in the dry season.
P J Murray - One of the best experts on this subject based on the ideXlab platform.
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the effects of acute exposure to mining machinery noise on the behaviour of eastern blue tongued lizards Tiliqua scincoides
Animal Welfare, 2017Co-Authors: Karen Mancera, P J Murray, A Lisle, C Dupont, F Faucheux, Clive J C PhillipsAbstract:The mining industry is an important source of noise for wildlife, and the eastern blue-tongued (EBT) lizard (Tiliqua scincoides) is an Australian animal that may be impacted. We analysed the behaviour of nine EBT lizards during and after exposure for 5 s to one of five combinations of mining machinery noise frequency and amplitude (frequency 2 kHz, low [60-65 dB (A)] and high [70-75 dB (A)] amplitude, or a control treatment). Following exposure, lizards could leave the test chamber and enter an escape chamber, which led into a small hiding chamber. Chambers were monitored for 15 min after initial exposure. In the test chamber, lizards exposed to high frequency, high amplitude noise spent more time freezing, a typical stress response in reptiles, when compared with animals in all the other treatments. This was especially the case for lizards exposed to high frequency noise. In the hiding chamber, high frequency noise at high amplitudes decreased durations of head positioning to the right and downwards, suggesting a lateralised fear reaction, but decreased standing and freezing behaviours. We hypothesise that lizards have lateralised behaviour reactions to mining noise, with high frequency, high amplitude noise being the most detrimental. Our results demonstrate that acute exposure to mining noise had negative effects on EBT lizards' behaviour and welfare, which may suggest a threat for lizards experiencing chronic mining noise in the wild, making the study of mining machinery noise in situ a research priority.
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the effects of simulated transport on the behaviour of eastern blue tongued lizards Tiliqua scincoides
Animal Welfare, 2014Co-Authors: Karen Mancera, P J Murray, A Lisle, Yn Gao, Cjc PhillipsAbstract:There is widespread transport of reptiles for the pet trade throughout the world and the 'dead on arrival' rates are high. The eastern blue tongued (EBT) lizard (Tiliqua scincoides; Order: Squamata; suborder: Lacertilia) is particularly popular due to its unusual blue tongue. Noise, vibration and thermal discomfort are known contributors to transport stress. We analysed the behaviour of EBT lizards (n = 9) when exposed to four of these stimuli in a changeover design. Lizards were exposed to Heat (35°C), Cold (15°C), high or low frequency noise or a Control treatment with no stimulus in a test chamber for a 5-s period. Heating blankets and ice packs were used to create the hot and cold temperature stimuli in the test chamber, and a speaker broadcast noise/vibration from a truck recording. The test chamber was connected to an escape chamber, accessible after exposure to the stimulus, and a small hiding chamber opposite the test chamber. Lizard behaviour was monitored during stimulus exposure and then for a further 15 min, after which each lizard was removed. Lizards exposed to Cold spent less time in the test chamber (330 vs 434 s) and more time inactive in the escape chamber (148 vs 40 s). They also spent longer walking towards the hiding chamber (18.0 vs 10.5 s) and walking in the hiding chamber away from the stimulus (3.6 vs 2.3 s). We conclude that cold temperatures are potentially noxious for lizards in a simulated transport environment as they reduce activity and increase escape attempts.
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environmental enrichment for captive eastern blue tongue lizards Tiliqua scincoides
Animal Welfare, 2011Co-Authors: Clive J C Phillips, Z Jiang, A J Hatton, A Tribe, Le M Bouar, M Guerlin, P J MurrayAbstract:Eastern blue-tongue lizards (Tiliqua scincoides) are kept in zoos and increasingly commonly as exotic pets, but little is known about improving their welfare by enrichment of their environment. Using nine animals kept individually in cages provided with a brick for basking and a pipe for hiding, we initially investigated enriching their environment with mealworms, either scattered on the floor or inserted into a foodball. The mealworms increased the time that the lizards spent feeding on both their ration and the mealworms and increased liveweight gain. Scattering the mealworms on the floor of their cages increased the time taken to eat them, compared with taking them from the foodball. Mealworms also reduced the time that the lizards spent hiding. Second, using eight individually housed lizards and replacing the pipe with a log which could be used both for basking and hiding, we investigated whether increasing the size of their enclosure and its temperature affected their behaviour, in a two-factor changeover design with two-week periods. When lizards were moved from small to large enclosures, they greatly increased the time that they spent walking on the first day, and they walked longer and further for the rest of the period. Lizards in big enclosures also spent more time hiding in the log and less time inactive on the log or the brick. Lizards in hot enclosures spent more time basking on the log and less time hiding in it, which would be valuable for display animals. The benefit of enriching the captive environment of Eastern blue-tongue lizards by scattering mealworms in their cage may depend on the effect on the lizards' weight and the cage's conditions, as captive lizards often become obese, and inactivity and weight loss are normal in their natural habitat during the dry season. Increasing the size of enclosures increases walking activity and reduces weight gain, which similarly will have variable effects on welfare depending on the impact on their bodyweight. Lizards in large enclosures have an increased propensity to hide so it is important that opportunities for this are provided.