Thermal niche overlap in garter snakes (Thamnophis) on Vancouver Island

1980 ◽  
Vol 58 (3) ◽  
pp. 351-355 ◽  
Author(s):  
Patrick T. Gregory ◽  
A. G. Duncan McIntosh

Although the three species of garter snakes (Thamnophis) on Vancouver Island have generally different diets, they overlap in food habits to some extent. Consequently, additional separation along other niche dimensions is expected. In this study, differences in thermal niches were examined in the field. Two of the three species had similar body temperatures and both were significantly different from the third. The linear relationship between body and substrate temperatures was not statistically different among species, however, allowing body temperatures to be directly related to habitat and (or) activity period differences. Extremes of habitat selection, rather than differences in diel activity periods, probably account for most of the interspecific variation in body temperature. On the other hand, the three species do coexist in some habitats and the observed differences in mean body temperature are small. Body temperature also varied slightly according to sex and reproductive condition, gravid females generally being warmer than other snakes.

2018 ◽  
Vol 66 (4) ◽  
pp. 235 ◽  
Author(s):  
Luh P. E. K. Yuni ◽  
Susan M. Jones ◽  
Erik Wapstra

Body temperatures in ectotherms are strongly affected by their thermal environment. Ectotherms respond to variation in the thermal environment either by modification of behavioural thermoregulation to maintain their optimal body temperature or by shifting their optimal body temperature. In this study, the body temperatures of males of three populations of spotted snow skinks, Niveoscincus ocellatus, living along an altitudinal gradient (low, mid, and high altitude) were studied in the field and laboratory in spring, summer, and autumn, representing the full activity period of this species. The environmental variation across both sites and seasons affected their field active body temperatures. At the low and mid altitude, N. ocellatus had a higher mean body temperature than at the high altitude. Animals achieved their thermal preference at the low and mid altitude sites in all seasons. At the high altitude, however, N. ocellatus struggled to reach its preferred body temperatures, especially in autumn. The lower body temperature at the high-altitude site is likely due to limited thermal opportunity and/or an effect of avoiding the costs associated with increased intensity of basking.


1984 ◽  
Vol 5 (1) ◽  
pp. 37-41 ◽  
Author(s):  
David Stubbs ◽  
Adrian Hailey ◽  
Elizabeth Pulford

AbstractThe mean body temperature of T. hermanni in woodland in France was 28.5 °C (August 1981). Body temperatures were elevated above air temperature and indirect evidence for basking and selection of an optimal microenvironment is discussed.


1960 ◽  
Vol 11 (5) ◽  
pp. 871 ◽  
Author(s):  
DF Dowling

An experiment was performed to test the effect of solar radiation on the body temperatures of cattle, both clipped and with hair coat, in a clear transparent plastic covering as compared with cattle in a white reflective plastic covering. The mean body temperature of the animals in white plastic coats was 0.15°F lower than that of animals in clear plastic coats. This difference was highly significant statistically (P< 0.001). Animals in both clear and white coats had higher body temperatures than controls without plastic coats. The difference was highly significant, and was about 1.5°F in the clipped animals.


2020 ◽  
Vol 47 (3) ◽  
pp. 249
Author(s):  
Yang Hu ◽  
Tim S. Doherty ◽  
Tim S. Jessop

Abstract Context Understanding how organismal attributes influence sensitivity to environmental perturbations is a central theme in ecology and conservation. Certain traits, such as body size, habitat use, dietary preference and reproductive output are considered important determinants of animal species’ responses to the impacts of ecological disturbances. However, the general relationships between functional traits and post-disturbance responses by animals are not fully understood. AimsOur primary aim was to use a meta-analysis to evaluate the influence of species traits on variation in population abundances of squamate reptiles (i.e. lizards and snakes). MethodsWe extracted data from 107 original published studies, from which 1027 mean effect sizes of post-disturbance responses by 298 species were estimated. We examined short-term responses only (i.e. within 3 years since the most recent disturbance). A comprehensive range of disturbances was examined, such as habitat destruction, fragmentation, fire, and exotic-species invasions. We used Bayesian linear mixed-effect modelling (BLMM), utilising the Markov-chain Monte Carlo algorithm (MCMC) for the meta-regression. Specifically, we tested the influence of eight species traits (body size, diet, temporal activity pattern, sociality, reproductive mode, clutch size, habitat selection, and mean body temperature), along with disturbance type, in explaining variation in species-specific abundance responses of squamate reptiles post-disturbance. Key resultsPost-disturbance abundance responses of squamate species were significantly influenced by two parameters, namely, mean body temperature and clutch size. In general, significant positive responses post-disturbance were observed for species with higher mean body temperatures and a greater clutch size. The type of disturbance had no detectable influence on squamate abundances. The influence of random effects (heterogeneity among studies and species, and broad taxonomic identity) accounted for more of the model variation than did the fixed effects (species traits and disturbance type). ConclusionsCertain species traits exerted some influence on the sensitivities of lizards and snakes to ecological disturbances, although the influence of random effects was very strong. Our findings are likely to be a result of the complexity and idiosyncratic nature of natural abundance patterns among animal species, in addition to the potential confounding effect of methodological differences among studies. ImplicationsThe present study is the first major quantitative synthesis of how species traits influence population-level responses of squamate reptiles to ecological disturbances. The findings can be used to guide conservation efforts and ecological management, such as by prioritising the efforts of mitigation on species that reproduce more slowly, and those with lower body temperatures.


1968 ◽  
Vol 71 (1) ◽  
pp. 61-66 ◽  
Author(s):  
M. E. D. Webster ◽  
K. G. Johnson

SummarySkin temperatures, deep body temperatures and respiratory rates have been measured in Southdown and Merino sheep following feeding, and during infra-red irradiation, rumen infusions of hot and cold water, and cold exposure induced by shearing. The increases in respiratory rate and skin temperatures induced by infra-red heating and the heat increment of feeding were reversed by addition of iced water to the rumen and were suppressed by shearing. These responses could not be systematically related to particular body temperatures in the sheep and appeared to be continuously variable rather than ‘all-or-none’ phenomena. Considerable overlap was observed between respiratory and vasomotor mechanisms of thermoregulation. Measurements of the surface area and weight of ears and legs showed that these regions contribute approximately 23% of the surface area and 8% of the body weight in Merino sheep. Calculations suggested that up to 70% of the additional heat produced in the 2 h after feeding in sheep may be stored in the tissues through increase in mean body temperature. Sheep kept in short wool throughout the winter appeared to establish a new thermoregulatory ‘set-point’ associated with lower rectal temperatures than those in sheep with a full fleece.


1987 ◽  
Vol 8 (4) ◽  
pp. 393-400 ◽  
Author(s):  
Benoit Heulin

AbstractMean body temperature (TC) of Lacerta vivpara ranges from 26°8 to 32° at Paimpont (France). There is a highly significant correlation between environmental temperatures (TS) and body temperatures (TC). The mean body temperature of pregnant females is lower than that of males and non-pregnant females. Also, the regression line TC = f(TS) calculated for pregnant females is different from those calculated for males and non-pregnant females. The possible relations between pregnancy and body temperature are discussed.


1984 ◽  
Vol 62 (11) ◽  
pp. 2244-2249 ◽  
Author(s):  
Patrick T. Gregory

The aim of this study was to determine the extent to which several environmental variables were associated with body temperatures of three species of garter snakes (Thamnophis) on Vancouver Island, and whether or not these associations changed with different activities of snakes. Perhaps because the data set was quite heterogeneous, no differences were observed between body temperatures of different species or sexes. In all activity groups, environmental temperatures were the variables most highly correlated with body temperatures; factors such as visible light intensity and cloud cover also were correlated with body temperature in some cases, but added little to the "explained" variation of body temperature. There was little evidence of seasonal or diel fluctuation in body temperature, but more careful data collection may be required to detect these. The correlation between body and environmental temperatures was highest for snakes under cover and lowest for moving snakes. Basking snakes in general were intermediate between these two groups, but snakes basking in the sun under sunny skies showed low correlation between body and environmental temperatures. Snakes, therefore, had body temperatures relatively independent of environmental temperatures under certain circumstances, but conclusions about thermoregulation could not be drawn from these data.


2005 ◽  
Vol 98 (4) ◽  
pp. 1207-1212 ◽  
Author(s):  
Thad E. Wilson ◽  
Jian Cui ◽  
Craig G. Crandall

Conflicting reports exist about the role of baroreflexes in efferent control of eccrine sweat rate. These conflicting reports may be due to differing mean body temperatures between studies. The purpose of this project was to test the hypothesis that mean body temperature modulates the effect of head-up tilt on sweat rate and skin sympathetic nerve activity (SSNA). To address this question, mean body temperature (0.9·internal temperature + 0.1·mean skin temperature), SSNA (microneurography of peroneal nerve, n = 8), and sweat rate (from an area innervated by the peroneal nerve and from two forearm sites, one perfused with neostigmine to augment sweating at lower mean body temperatures and the second with the vehicle, n = 12) were measured in 13 subjects during multiple 30° head-up tilts during whole body heating. At the end of the heat stress, mean body temperature (36.8 ± 0.1 to 38.0 ± 0.1°C) and sweat rate at all sites were significantly elevated. No significant correlations were observed between mean body temperature and the change in SSNA during head-up tilt ( r = 0.07; P = 0.62), sweating within the innervated area ( r = 0.06; P = 0.56), sweating at the neostigmine treated site ( r = 0.04; P = 0.69), or sweating at the control site ( r = 0.01; P = 0.94). Also, for each tilt throughout the heat stress, there were no significant differences in sweat rate (final tilt sweat rates were 0.69 ± 0.11 and 0.68 ± 0.11 mg·cm−2·min−1 within the innervated area; 1.04 ± 0.16 and 1.06 ± 0.16 mg·cm−2·min−1 at the neostigmine-treated site; and 0.85 ± 0.15 and 0.85 ± 0.15 mg·cm−2·min−1 at the control site, for supine and tilt, respectively). Hence, these data indicate that mean body temperature does not modulate eccrine sweat rate during baroreceptor unloading induced via 30° head-up tilt.


2006 ◽  
Vol 84 (5) ◽  
pp. 771-777 ◽  
Author(s):  
Deborah I. Lutterschmidt ◽  
Michael P. LeMaster ◽  
Robert T. Mason

Red-sided garter snakes ( Thamnophis sirtalis parietalis (Say in James, 1823)) in Manitoba, Canada, undergo 8 months of continuous winter dormancy prior to spring emergence. As in other ectothermic species, increases in ground temperature may be the cue for emergence from winter dormancy in these populations. To test this hypothesis, we measured body temperatures during winter dormancy by surgically implanting small temperature loggers into 32 female red-sided garter snakes before they entered their native hibernaculum. The following spring, we recaptured seven of the snakes implanted with temperature loggers. Body temperature declined gradually from mid-September (14.7 ± 0.24 °C, mean  ± SE) to early April (1.1 ± 0.16 °C, mean ± SE) during winter dormancy, reaching minimal values approximately 1 month prior to spring emergence. Body temperatures of emerging snakes ranged from 0.5 °C during early spring to 6.3 °C during late spring (3.4 ± 0.84 °C, mean ± SE). These results do not support the hypothesis that an increase in ground temperature (and hence body temperature) is necessary for emergence from winter dormancy. We suggest that critically low temperatures (i.e., 0.5–1 °C) are a Zeitgeber entraining an endogenous circannual cycle that regulates snake emergence. These results offer new insight into the mechanisms regulating seasonal emergence from winter dormancy.


1993 ◽  
Vol 71 (11) ◽  
pp. 2152-2155 ◽  
Author(s):  
Geoffrey R. Smith ◽  
Royce E. Ballinger ◽  
Justin D. Congdon

The thermal ecology of a high-altitude lizard, Sceloporus scalaris, was investigated in the Chiricahua Mountains of southeastern Arizona, where the lizards are active on sunny days throughout the year. Mean body temperature was 32.6 °C (range 12.6–39 °C) and mean air temperature was 20.2 °C (range 5.2–36.4 °C). The slope of the body temperature versus air temperature regression was 0.23. Monthly differences in body temperature were observed, with the highest body temperatures observed in early summer. Lizards at three study sites with differing slope and vegetative cover had different mean body temperatures. Males had higher body temperatures than both nongravid and gravid females. Maintenance of elevated body temperatures even during winter lengthens the activity and growing season, permitting early maturity with potentially important life-history consequences.


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