scholarly journals Northern Snakes Appear Much More Abundant in Old Fields than in Forests

2018 ◽  
Vol 131 (3) ◽  
pp. 228-234
Author(s):  
Francisco Retamal Diaz ◽  
Gabriel Blouin-Demers
Keyword(s):  
Habitat Selection ◽  
Thermal Conditions ◽  
Strong Preference ◽  
Thamnophis Sirtalis ◽  
Old Fields ◽  
Behavioural Thermoregulation ◽  
Body Temperatures ◽  
Forest Habitat ◽  
Thermal Constraints ◽  
Northern Latitudes

Temperature is one of the most important factors regulating habitat selection by ectotherms. Through behavioural thermoregulation, reptiles maintain preferred body temperatures and thereby maximize fitness. At northern latitudes, small colubrids appear to use forest habitat rarely because of thermal constraints. In cool environments, open habitats such as old fields offer more favourable thermal conditions than forest. We studied two northern colubrid snakes, Red-bellied Snake (Storeria occipitomaculata) and Common Gartersnake (Thamnophis sirtalis), in Gatineau Park, Quebec, Canada, to test the hypothesis that small northern snakes are more abundant in open than in closed habitats because open habitats provide better opportunities for thermoregulation. Snakes were sampled using large arrays of tin and plywood coverboards. Snakes were indeed much more abundant in old fields than in forest, and fields offered more favourable thermal conditions. Most snakes were captured in spring and summer (May to August) when temperatures were highest. Storeria occipitomaculata preferred tin over plywood coverboards. We confirmed an apparent strong preference for open habitats in northern snakes.

Vulnerability to global warming of a Critically Endangered lizard from the Monte Desert, Patagonia Argentina

2021 ◽  
Author(s):  
María Victoria Brizio ◽  
Facundo Cabezas-Cartes ◽  
Jimena Beatriz Fernández ◽  
Rodrigo Gómez Alés ◽  
Luciano Javier Avila
Keyword(s):  
Global Warming ◽  
Thermal Sensitivity ◽  
Thermal Conditions ◽  
Sun Exposure ◽  
Critically Endangered ◽  
Body Temperatures ◽  
Monte Desert ◽  
Safety Margins ◽  
Environmental Temperatures

Reptiles’ body temperature is strongly influenced by the thermal quality of microhabitats, exploiting the favourable environmental temperatures, and avoiding exposure to extreme thermal conditions. For these reasons, reptiles’ populations are considered to be especially vulnerable to changes in environmental temperatures produced by climate change. Here, we study the thermal physiology of the Critically Endangered lizard Liolaemus cuyumhue Avila, Morando, Perez and Sites, 2009. We hypothesise that, (1) there is a thermal coadaptation between optimal temperature for locomotor performance of L. cuyumhue and its thermal preference; (2) L. cuyumhue lives in an environment with low thermal quality; (3) a raise in environmental temperatures due to global warming will impose a decrement in locomotor speed represented by lower warming tolerance and narrower thermal safety margins, increasing their already high vulnerability. We registered field body temperatures (Tb), preferred body temperatures (Tpref), the operative (Te), and the thermal sensitivity of locomotion at different body temperatures. Our results indicate that this lizard is not currently under environmental stress or exceeding its thermal limits, but that it is thermorregulating below Tpref to avoid overheating, and that an increase in environmental temperature higher than 3.5 °C will strongly affect the use of microhabitats with direct sun exposure.

Activity times and body temperature in Australian copperheads (Serpentes : Elapidae)

2001 ◽  
Vol 49 (3) ◽  
pp. 223 ◽  
Author(s):  
Detlef H. Rohr ◽  
Brian S. Malone
Keyword(s):  
Body Temperature ◽  
Thermal Conditions ◽  
Climatic Conditions ◽  
Temperate Climate ◽  
Body Temperatures ◽  
Active Season ◽  
Eastern Australia ◽  
Cool Temperate ◽  
Warm Temperate ◽  
Activity Times

Local climatic conditions influence the way in which ectotherms regulate their body temperature and activity. We examined correlations between local climatic conditions, body temperature and activity in adult, basking lowland copperheads (Austrelaps superbus) from two localities (warm-temperate versus cool-temperate) in south-eastern Australia. We also collected data from highland copperheads (Austrelaps ramsayi) at a locality with cold-temperate climate. We found that across the active season, mean body temperatures were similar among localities (approximately 27˚C) irrespective of species. In contrast, activity times differed. Cool-temperate A. superbus emerged earlier in spring and in the morning and retreated earlier in the evening and in autumn than their conspecifics from the warm-temperate locality. Spring emergence was correlated with yearly fluctuations in thermal conditions, suggesting that activity times depend on environmental temperatures. Predator–prey interactions influenced body temperature and activity to some extent in spring when warm-temperate A. superbus with relatively low body temperatures (as low as 18.5˚C) were captured around ponds in which they had been foraging for frogs. Austrelaps ramsayi from the cold-temperate locality not only displayed a later emergence in spring and reduced daily activity times compared with warm and cool-temperate A. superbus but also compared with A. ramsayi, as reported from a warmer locality in eastern Australia. These data indicate that activity times vary on a geographic basis while snake body temperatures largely remain inflexible. The surprising exception was that cold-temperate A. ramsayi retreated later in autumn than cool-temperate A. superbus, and at that time they showed body temperatures as low as 12.5˚C, well below those we had recorded for A. superbus. We suggest that A. ramsayi retreat later in autumn because they need to extend their reproductive season and that this is mediated via adaptive changes in the critical minimum body temperature, as has been reported for other snakes.

Temperature regulation in the tortoise Testudo hermanni, studied with indwelling probes

1996 ◽  
Vol 17 (2) ◽  
pp. 91-102 ◽  
Author(s):  
C. Huot-Daubremont ◽  
D. Bradshaw ◽  
C. Grenot
Keyword(s):  
Temperature Regulation ◽  
Temperature Sensitive ◽  
Behavioural Thermoregulation ◽  
Body Temperatures ◽  
South Eastern ◽  
Testudo Hermanni ◽  
Free Ranging

AbstractBehavioural thermoregulation has been studied in the terrestrial tortoise Testudo hermanni in south-eastern France by implanting temperature-sensitive probes in free-ranging individuals. Three tortoises were monitored over a period of nine months (July to March); they maintained body temperatures close to their preferendum for periods of several hours each day. These results are of interest as doubt has been expressed in the literature on the thermoregulatory capacities of Testudo hermanni in the northernmost part of its range.

Warming up for cold water: influence of habitat type on thermoregulatory tactics in a semi-aquatic snake

2010 ◽  
Vol 31 (4) ◽  
pp. 525-531 ◽  
Author(s):  
Radika Michniewicz ◽  
Fabien Aubret
Keyword(s):  
Body Temperature ◽  
Muscle Function ◽  
Cold Water ◽  
Habitat Type ◽  
Thermal Conditions ◽  
Aquatic Environments ◽  
Behavioural Thermoregulation ◽  
Foraging Success ◽  
Sharp Drop ◽  
Performance Time

AbstractIn ectotherms, thermal acclimation and behavioural thermoregulation have evolved to match organismal performance with local or temporary thermal conditions. In semi-aquatic species, however, this matching encompasses a trade-off: organisms that thermoregulate close to optimal muscle function on land will inevitably depart from that optimum when entering water, a medium that may differ drastically in temperature. With regard to predator evasion and foraging success, how do semi-aquatic ectotherms deal with such a challenge? We experimentally raised young semi-aquatic Tiger snakes in either terrestrial or semi-aquatic environments over 11 months. When tested in a standardised enclosure, young snakes raised in a semi-aquatic environment selected slightly, but significantly higher mean body temperatures than their terrestrially raised siblings (respectively 30.3°C versus 29.5°C). The former allowed their body temperature to remain higher than 32°C for twice as long as the latter group (4.4 hours vs 2.1 hours). Locomotor performances (swimming speed) were, unsurprisingly, strongly linked to body temperature. Entering water with a higher body temperature (30°C versus 19°C) delayed a sharp drop in locomotor performances, and thus lengthened maximum performance time. We hypothesise that young snakes, by allowing their body temperature to reach above their usual optimum body temperature, may delay the drop in locomotor efficiency in case of foraging opportunity or in order to escape a predator.

Home range, habitat selection and diet of foxes (Vulpes vulpes) in a semi-urban riparian environment

2006 ◽  
Vol 33 (3) ◽  
pp. 175 ◽  
Author(s):  
John G. White ◽  
Robert Gubiani ◽  
Nathalie Smallman ◽  
Kelly Snell ◽  
Anne Morton
Keyword(s):  
Habitat Selection ◽  
Home Range ◽  
Vulpes Vulpes ◽  
Active Avoidance ◽  
Strong Preference ◽  
Vegetation Types ◽  
Habitat Manipulation ◽  
The Mean ◽  
Manipulation Strategy ◽  
Selection Of

Between 2000 and 2002 the home range, habitat selection and diet of foxes were examined in the Dandenong Creek Valley, Melbourne, Australia. The mean home range was 44.6 ha (range 19.2–152.6 ha). A significant selection towards blackberry and gorse used as diurnal shelter was found during the day with an active avoidance of less structurally complex vegetation types. Although there was obvious selection of certain habitats, the diet of the foxes was highly general and opportunistic and thus offers little potential as a factor to manipulate in order to reduce fox abundance. Given the strong preference for blackberry and gorse as a shelter resource, a habitat-manipulation strategy is suggested whereby patches of blackberry and gorse are removed and replaced with less structurally complex vegetation. Such a strategy has the potential to influence the density of foxes in semi-urban riparian environments such as those discussed in this study.

Behavioural Thermoregulation in the Freeze-Tolerant Arctic Caterpillar, Gynaephora Groenlandica

1988 ◽  
Vol 138 (1) ◽  
pp. 181-193 ◽  
Author(s):  
OLGA KUKAL ◽  
BERND HEINRICH ◽  
JOHN G. DUMAN
Keyword(s):  
Solar Radiation ◽  
Growth And Development ◽  
High Arctic ◽  
The Sun ◽  
Metabolic Rates ◽  
Behavioural Thermoregulation ◽  
Body Temperatures ◽  
Feeding Site ◽  
Freeze Tolerant ◽  
Gynaephora Groenlandica

Larvae of the high arctic caterpillar, Gynaephora groenlandica (Wöcke) (Lepidoptera: Lymantriidae) spent most (60 %) of their time orienting towards the sun (i.e. basking) and only 20% feeding, primarily near midday. Larvae usually basked after feeding, then either fed again or moved to a new feeding site. Basking larvae reached their highest body temperatures (Tb) of ≊30°C (≊20°C in excess of the ambient temperature) when surrounded by snow on a calm day in the midday sun. Setae significantly decreased larval cooling rates. Maximal metabolic rates were attained in basking larvae, but at body temperatures below 10°C oxygen uptake was greatly reduced. Our studies indicate that G. groenlandica larvae are behaviourally adapted to utilize available solar radiation for growth and development.

scholarly journals Plasticity of preferred body temperatures as means of coping with climate change?

2011 ◽  
Vol 8 (2) ◽  
pp. 262-265 ◽  
Author(s):  
Lumír Gvoždík
Keyword(s):  
Climate Change ◽  
Adaptive Capacity ◽  
Thermal Environment ◽  
Global Climate ◽  
Thermal Conditions ◽  
Body Temperatures ◽  
Widespread Occurrence ◽  
The Impact ◽  
Thermoregulatory Behaviour

Thermoregulatory behaviour represents an important component of ectotherm non-genetic adaptive capacity that mitigates the impact of ongoing climate change. The buffering role of behavioural thermoregulation has been attributed solely to the ability to maintain near optimal body temperature for sufficiently extended periods under altered thermal conditions. The widespread occurrence of plastic modification of target temperatures that an ectotherm aims to achieve (preferred body temperatures) has been largely overlooked. I argue that plasticity of target temperatures may significantly contribute to an ectotherm's adaptive capacity. Its contribution to population persistence depends on both the effectiveness of acute thermoregulatory adjustments (reactivity) in buffering selection pressures in a changing thermal environment, and the total costs of thermoregulation (i.e. reactivity and plasticity) in a given environment. The direction and magnitude of plastic shifts in preferred body temperatures can be incorporated into mechanistic models, to improve predictions of the impact of global climate change on ectotherm populations.

Thermoregulatory Aspects of Behavior in the Blue Spiny Lizard Scelopor Us Cyanogenys (Sauria, Iguanidae)

Behaviour ◽  
1976 ◽  
Vol 59 (1-2) ◽  
pp. 1-21 ◽  
Author(s):  
Neil Greenberg
Keyword(s):  
Body Temperature ◽  
Radio Telemetry ◽  
Thermal Conditions ◽  
Normal Activity ◽  
The Body ◽  
Body Temperatures ◽  
Natural Behavior ◽  
Thermal Range ◽  
Large Repertoire ◽  
Thermal Relations

Abstract1. The thermal relations of blue spiny lizards, Sceloporus cyanogenys, were studied in laboratory habitats which were designed to allow the expression of a large repertoire of natural behavior patterns. Body temperatures obtained with fast-reading thermometers and by radio telemetry from implanted transmitters were correlated with postures and activities. 2. The morning emergence of lizards was found to be cued by light, often in the absence of immediate thermal reinforcement. 3. Two basking postures which altered a lizard's air and substrate thermal interfaces could be distinguished. The environmental and body temperature correlates of these postures were not appreciably different, and the change from one posture to another could not be interpreted as thermoregulatory. 4. When thermal conditions permitted, basking continued up to the attainment of the maximum voluntary body temperature (38.7 C), and was then followed by perching. 5. The body temperature correlates of perching had a range and mean much like the "normal activity range" of other species of Sceloporus (28.2-38.7 C, X= 35.2). 6. Defecation occurred mostly in the morning towards the end of the basking period, but had a broad thermal range (27.5 to 35.7 C). 7. The range of body temperatures during feeding was broad (25.3-38.5 C), but that of foraging was much narrower (34.3-38.7 C).

scholarly journals Broad seasonal changes in thermoregulation of Podarcis lilfordi (Squamata, Lacertidae) at Binicodrell islet (Menorca, Spain)

Herpetozoa ◽  
2019 ◽  
Vol 32 ◽  
pp. 57-63 ◽  
Author(s):  
Zaida Ortega ◽  
Abraham Mencía ◽  
Aline Giroux ◽  
Valentín Pérez-Mellado
Keyword(s):  
Seasonal Changes ◽  
Environmental Changes ◽  
Sunlight Exposure ◽  
Behavioural Thermoregulation ◽  
Body Temperatures ◽  
Island Populations ◽  
Know How ◽  
Podarcis Lilfordi ◽  
Wind Intensity ◽  
Operative Temperatures

Most lizards maintain quite constant body temperatures by behavioural means. Seasonal variations of environmental factors, such as temperature, sunlight exposure and wind intensity, influence lizard thermoregulatory abilities. Understanding how seasonal environmental shifts influence lizards’ thermoregulation helps us to know how they deal behaviourally with environmental changes, in general. We examined seasonal shifts (spring vs. summer) in behavioural thermoregulation in Podarcislilfordi from Binicodrell islet (Menorca, Spain). Operative temperatures varied between microhabitats and seasons, being lower in spring than in summer, regardless of sunlight exposure. Lizard body temperatures were also lower in spring than in summer. Lizards used sunny microhabitats more frequently in spring and shaded areas in summer. Habitat thermal quality was similar during both seasons, but lizards thermoregulated less accurately in spring than in summer. Thermoregulatory effectiveness was low in spring (0.28) and moderate in summer (0.76). In comparison with previously published results, our findings showed the marked seasonal variation in the effectiveness of thermoregulation amongst island populations, which should be considered in future comparative studies.

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