scholarly journals Do Incubation Temperatures Affect the Preferred Body Temperatures of Hatchling Velvet Geckos?

2021 ◽  
Vol 9 ◽  
Author(s):  
Theja Abayarathna ◽  
Jonathan K. Webb
Keyword(s):  
Body Size ◽  
Thermal Gradient ◽  
Nest Site ◽  
Interquartile Range ◽  
Learning Ability ◽  
Locomotor Performance ◽  
Body Temperatures ◽  
Access To Food ◽  
Incubation Temperatures ◽  
Thermal Preferences

In many lizards, a mother’s choice of nest site can influence the thermal and hydric regimes experienced by developing embryos, which in turn can influence key traits putatively linked to fitness, such as body size, learning ability, and locomotor performance. Future increases in nest temperatures predicted under climate warming could potentially influence hatchling traits in many reptiles. In this study, we investigated whether future nest temperatures affected the thermal preferences of hatchling velvet geckos, Amalosia lesueurii. We incubated eggs under two fluctuating temperature treatments; the warm treatment mimicked temperatures of currently used communal nests (mean = 24.3°C, range 18.4–31.1°C), while the hot treatment (mean = 28.9°C, range 20.7–38.1°C) mimicked potential temperatures likely to occur during hot summers. We placed hatchlings inside a thermal gradient and measured their preferred body temperatures (Tbs) after they had access to food, and after they had fasted for 5 days. We found that hatchling feeding status significantly affected their preferred Tbs. Hatchlings maintained higher Tbs after feeding (mean = 30.6°C, interquartile range = 29.6–32.0°C) than when they had fasted for 5 d (mean = 25.8°C, interquartile range = 24.7–26.9°C). Surprisingly, we found that incubation temperatures did not influence the thermal preferences of hatchling velvet geckos. Hence, predicting how future changes in nest temperatures will affect reptiles will require a better understanding of how incubation and post-hatchling environments shape hatchling phenotypes.

scholarly journals Hotter nests produce smarter young lizards

2012 ◽  
Vol 8 (3) ◽  
pp. 372-374 ◽  
Author(s):  
Joshua J. Amiel ◽  
Richard Shine
Keyword(s):  
Climate Change ◽  
Site Selection ◽  
Cognitive Skills ◽  
Nest Site ◽  
Incubation Temperature ◽  
Nest Site Selection ◽  
Learning Performance ◽  
Locomotor Performance ◽  
Incubation Temperatures ◽  
Bassiana Duperreyi

A hatchling reptile's sex, body size and shape, and locomotor performance can be influenced not only by its genes, but also by the temperature that it experiences during incubation. Can incubation temperature also affect a hatchling's cognitive skills? In the scincid lizard Bassiana duperreyi , higher incubation temperatures enhanced the resultant hatchling's learning performance. Hence, factors such as maternal nest-site selection and climate change affect not only the size, shape and athletic abilities of hatchling reptiles, but also their ability to learn novel tasks.

Locomotor Performance in Highly-Trained Young Soccer Players: Does Body Size Always Matter?

2013 ◽  
Vol 35 (06) ◽  
pp. 494-504 ◽  
Author(s):  
M. Buchheit ◽  
A. Mendez-Villanueva ◽  
N. Mayer ◽  
H. Jullien ◽  
A. Marles ◽  
...  
Keyword(s):  
Body Size ◽  
Soccer Players ◽  
Locomotor Performance

The roles of acidosis and lactate in the behavioral hypothermia of exhausted lizards

1999 ◽  
Vol 202 (3) ◽  
pp. 325-331
Author(s):  
E.L. Wagner ◽  
D.A. Scholnick ◽  
T.T. Gleeson
Keyword(s):  
Blood Lactate ◽  
Thermal Gradient ◽  
Elevated Blood ◽  
Body Temperatures ◽  
Exhausting Exercise ◽  
A Value ◽  
Arterial Ph ◽  
Injection Control ◽  
The Mean ◽  
Lactate Levels

We conducted this study to determine whether two of the physiological changes associated with non-sustainable exercise, elevated blood lactate levels and decreased arterial pH, contribute to the behavioral hypothermia exhibited by exhausted lizards. Dipsosaurus dorsalis were placed in a thermal gradient and their body temperatures were recorded from 08:00 to 14:00 h. At 14:00 h, animals were subjected to different experimental regimens. In the exercise (E) regimen, animals at 40 degrees C were forced to exercise maximally for 5 min on a treadmill. In the lactate (L) regimen, animals were infused with 11.5 ml kg-1 of 250–500 mmol l-1 sodium lactate. In the osmolarity control (O) regimen, animals were injected with 11.5 ml kg-1 of 500 mmol l-1 NaCl, and in the injection control (I) regimen, animals were injected with 11.5 ml kg-1 of 150 mmol l-1 NaCl. In the hypercapnia (H) regimen, the thermal gradient was flushed with a gas mixture containing 10 % CO2, 21 % O2 and 69 % N2, a treatment that lowers the arterial pH of D. dorsalis to a value comparable with that imposed by exhaustive exercise. A group of control (C) animals was left undisturbed in the thermal gradient for 24 h. Animals in all experimental groups were returned to the thermal gradient, and their cloacal temperatures were monitored until 08:00 h the following morning. The mean cloacal temperature of E animals underwent a significant decrease of 4–7 degrees C, relative to control animals, which persisted for 7 h. The mean cloacal temperatures of animals subjected to 2 h of regimen H also decreased by 3.5-9 degrees C and remained depressed for 12 h following the beginning of the treatment. L, O and I animals did not undergo a significant change in body temperature following treatment, and their mean body temperatures did not differ from those of C animals at any time during the experiment. The results of this study suggest that the metabolic acidosis, but not the elevated blood lactate level, that follows exhausting exercise might play a role in the behavioral hypothermia that follows exhausting exercise in D. dorsalis.

Thermal dependence of locomotor capacity

1990 ◽  
Vol 259 (2) ◽  
pp. R253-R258 ◽  
Author(s):  
A. F. Bennett
Keyword(s):  
Cold Exposure ◽  
Environmental Temperature ◽  
Locomotor Performance ◽  
Evolutionary Adaptation ◽  
Body Temperatures ◽  
Thermal Dependence ◽  
Performance Capacity ◽  
High Body ◽  
Locomotor Capacity ◽  
Lethal Limits

The thermal dependence of locomotor performance capacity, particularly speed and endurance, in vertebrate ectotherms is examined. Most studies have found an optimal speed for performance at relatively high body temperatures, close to upper lethal limits. These performance capacities decrease markedly at low body temperatures and may be compensated by increments in aggressive or evasive behaviors. Relative ranking of performance is maintained among individuals across body temperatures. Acclimation of performance capacities is generally incomplete or entirely absent: most animals compensate locomotor performance rather poorly to cold exposure. Locomotor performance in different groups has been shown to possess the attributes (e.g., variability, repeatability, heritability, and differential survivorship) necessary for evolutionary adaptation, but interpretation of comparative data is complicated by phylogenetic differences among species studied. Controlled studies show partial but incomplete adaptation to environmental temperature.

Operant control of ambient temperature during sleep deprivation

1997 ◽  
Vol 272 (2) ◽  
pp. R682-R690 ◽  
Author(s):  
P. J. Shaw ◽  
B. M. Bergmann ◽  
A. Rechtschaffen
Keyword(s):  
Energy Expenditure ◽  
Sleep Deprivation ◽  
Ambient Temperature ◽  
Thermal Gradient ◽  
Progressive Increase ◽  
Thermal Preference ◽  
Body Temperatures ◽  
Progressive Decline ◽  
Baseline Levels ◽  
Almost All

Rats subjected to total sleep deprivation (TSD) by the disk-over-water method were provided with a continuously available operant by which they could increase ambient temperature (T(amb)). TSD rats progressively increased operant responses for heat to 700% of baseline levels. During the last quarter of sleep deprivation, they maintained mean T(amb) at 9 degrees C above baseline and held T(amb) over 40 degrees C for 35% of the day. In contrast, yoked control rats (TSC) did not change mean T(amb). Although both TSD and TSC rats showed a progressive decline in intraperitoneal temperature (T(ip)), TSD rats maintained an elevated T(amb) even during periods when T(ip) and brain temperatures (T(br)) were above baseline levels. Thus these results confirm and extend earlier findings that rats subjected to TSD show an increase in temperature set point (T(set)). The earlier studies, which utilized short daily trials in a thermal gradient, demonstrated an increase in T(set) early in the deprivation period. The present study, which obtained more extensive data on thermal preference at a range of body temperatures demonstrated an increasing T(amb) for almost all T(ip) and T(br) values, suggesting a progressive increase in T(set) over the course of sleep deprivation. Surprisingly, survival time was shorter than in previous TSD studies. Reduced survival could not be attributed to differences in T(br), T(ip), energy expenditure, or sleep loss from previous studies.

scholarly journals Incubation under climate warming affects learning ability and survival in hatchling lizards

2017 ◽  
Vol 13 (3) ◽  
pp. 20170002 ◽  
Author(s):  
Buddhi Dayananda ◽  
Jonathan K. Webb
Keyword(s):  
Spatial Learning ◽  
Climate Warming ◽  
Cognitive Abilities ◽  
Incubation Temperature ◽  
Learning Ability ◽  
Lizard Species ◽  
Southeastern Australia ◽  
Temperature Regimes ◽  
In The Wild ◽  
Incubation Temperatures

Despite compelling evidence for substantial individual differences in cognitive performance, it is unclear whether cognitive ability influences fitness of wild animals. In many animals, environmental stressors experienced in utero can produce substantial variation in the cognitive abilities of offspring. In reptiles, incubation temperatures experienced by embryos can influence hatchling brain function and learning ability. Under climate warming, the eggs of some lizard species may experience higher temperatures, which could affect the cognitive abilities of hatchlings. Whether such changes in cognitive abilities influence the survival of hatchlings is unknown. To determine whether incubation-induced changes in spatial learning ability affect hatchling survival, we incubated velvet gecko, Amalosia lesueurii , eggs using two fluctuating temperature regimes to mimic current (cold) versus future (hot) nest temperatures. We measured the spatial learning ability of hatchlings from each treatment, and released individually marked animals at two field sites in southeastern Australia. Hatchlings from hot-incubated eggs were slower learners than hatchlings from cold-incubated eggs. Survival analyses revealed that hatchlings with higher learning scores had higher survival than hatchlings with poor learning scores. Our results show that incubation temperature affects spatial learning ability in hatchling lizards, and that such changes can influence the survival of hatchlings in the wild.

A computational analysis of locomotor anatomy and body mass evolution in Allosauroidea (Dinosauria: Theropoda)

Paleobiology ◽  
2012 ◽  
Vol 38 (3) ◽  
pp. 486-507 ◽  
Author(s):  
Karl T. Bates ◽  
Roger B. J. Benson ◽  
Peter L. Falkingham
Keyword(s):  
Body Size ◽  
Soft Tissue ◽  
Center Of Mass ◽  
Soft Tissue Reconstruction ◽  
Locomotor Performance ◽  
Body Proportions ◽  
Data Set ◽  
Positive Allometry ◽  
Moment Arms ◽  
Musculoskeletal Anatomy

We investigate whether musculoskeletal anatomy and three-dimensional (3-D) body proportions were modified during the evolution of large (>6000 kg) body size in Allosauroidea (Dinosauria: Theropoda). Three adaptations for maintaining locomotor performance at large body size, related to muscle leverage, mass, and body proportions, are tested and all are unsupported in this analysis. Predictions from 3-D musculoskeletal models of medium-sized (Allosaurus) and large-bodied (Acrocanthosaurus) allosauroids suggest that muscle leverage scaled close to isometry, well below the positive allometry required to compensate for declining muscle cross-sectional area with increasing body size. Regression analyses on a larger allosauroid data set finds slight positive allometry in the moment arms of major hip extensors, but isometry is included within confidence limits. Contrary to other recent studies of large-bodied theropod clades, we found no compelling evidence for significant positive allometry in muscle mass between exemplar medium- and large-bodied allosauroids. Indeed, despite the uncertainty in quantitative soft tissue reconstruction, we find strong evidence for negative allometry in the caudofemoralis longus muscle, the single largest hip extensor in non-avian theropods. Finally, we found significant inter-study variability in center-of-mass predictions for allosauroids, but overall observe that consistently proportioned soft tissue reconstructions produced similar predictions across the group, providing no support for a caudal shift in the center of mass in larger taxa that might otherwise reduce demands on hip extensor muscles during stance. Our data set provides further quantitative support to studies that argue for a significant decline in locomotor performance with increasing body size in non-avian theropods. However, although key pelvic limb synapomorphies of derived allosauroids (e.g., dorsomedially inclined femoral head) evolved at intermediate body sizes, they may nonetheless have improved mass support.

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