Thermal ecology of Massasauga Rattlesnakes (Sistrurus catenatus) near their northern range limit

2011 ◽  
Vol 89 (1) ◽  
pp. 60-68 ◽  
Author(s):  
Daniel S. Harvey ◽  
Patrick J. Weatherhead
Keyword(s):  
Body Temperature ◽  
Foraging Ecology ◽  
Range Limit ◽  
Elaphe Obsoleta ◽  
Nerodia Sipedon ◽  
Cool Environment ◽  
Sistrurus Catenatus ◽  
Northern Range Limit ◽  
Preferred Body Temperature ◽  
Thermoregulatory Behaviour

Using populations at their northern range limits, we compared the thermoregulatory behaviour of Massasauga Rattlesnakes ( Sistrurus catenatus (Rafinesque, 1818)) to published results for Ratsnakes ( Elaphe obsoleta (Say in James, 1823)) and Northern Watersnakes ( Nerodia sipedon (L., 1758)) to test the hypothesis that given similar benefits of thermoregulation, costs associated with foraging ecology should shape thermoregulatory behaviour. More than 32 000 body temperature measurements from 34 individual snakes over 4 years were used to quantify thermoregulation by Massasauga Rattlesnakes using standard indices and a new index (%MaxE) that describes how much of the thermoregulatory potential available to a snake is realized. On average, Massasaugas were much cooler (db = 6.9 °C) than their preferred body temperature range (30–33.6 °C) but warmer (de – db = 3.3 °C) than were they not thermoregulating. Massasaugas realized more than half of their environmental potential for effective thermoregulation (%MaxE = 64%). Consistent with there being less conflict between foraging and thermoregulation for ambush predators than active foragers, Massasaugas were more effective thermoregulators than Ratsnakes or Watersnakes during the day. All three species were effective thermoregulators at night, supporting the assumption that species in a cool environment will thermoregulate when there are few competing interests.

Green Turtles Nesting at Their Northern Range Limit in the United States Represent a Distinct Subpopulation

2018 ◽  
Vol 17 (2) ◽  
pp. 314 ◽  
Author(s):  
Brian M. Shamblin ◽  
Matthew H. Godfrey ◽  
S. Michelle Pate ◽  
William P. Thompson ◽  
Hope Sutton ◽  
...  
Keyword(s):  
United States ◽  
The United States ◽  
Range Limit ◽  
Green Turtles ◽  
Distinct Subpopulation ◽  
Northern Range Limit

The ecology of the island-lizard Podarcis sicula salfii

1981 ◽  
Vol 2 (3) ◽  
pp. 243-257 ◽  
Author(s):  
P.E. Ouboter
Keyword(s):  
Body Temperature ◽  
Interspecific Competition ◽  
The Sun ◽  
Podarcis Sicula ◽  
Dense Vegetation ◽  
Food Size ◽  
Preferred Body Temperature ◽  
Erica Arborea ◽  
Sufficient Food ◽  
Excursion Time

AbstractIn the summers of 1974 till 1979 microdistribution of Podarcis sicula saffti was examined. Areas without much vegetation and areas with dense vegetation have low densities. Horizontal space, predators, parasites, interspecific competition, shelter and dew appear to be non important factors in the microdistribution of P. s. safii. From 9 a. m. until 6 p. m. temperature in the sun is above PBT (preferred-body-temperature) in all zones. Shade temperature is different from one zone to another. In the most rocky zone without much vegetation, shade is provided by crevices. Shade temperature is under PBT. Food is mainly available outside crevices, in vegetation of Statice sinuatum. Food-size is small, so excursion-time will be long. Lizards are able to collect sufficient food if Statice-plants are close to crevices. The zone with vegetation of Erica arborea, on top of the island, is shaded all day. Shade temperature is under PBT. Only clearings are inhabited by lizards. All other zones have bushes and open areas. During the hot hours bushes provide shade, with shade temperature close to PBT. Food is mainly available in these bushes.

Breeding behaviour of ectotherms at high latitudes: the case of the natterjack toad Epidalea calamita at its northern range limit

Behaviour ◽  
2021 ◽  
pp. 1-20
Author(s):  
Linda Saare ◽  
Riinu Rannap
Keyword(s):  
Climatic Conditions ◽  
Energetic Cost ◽  
Breeding Period ◽  
High Latitudes ◽  
Range Limit ◽  
Photo Identification ◽  
Breeding Behaviour ◽  
Risk Of Predation ◽  
Increased Risk ◽  
Northern Range Limit

Abstract We explored the breeding behaviour of a threatened amphibian, the natterjack toad, at its northern range limit in Estonia, to determine the extent to which reproduction is affected by harsh and unstable climatic conditions. Using photo identification of specimens, we found that in optimal weather conditions males formed three breeding cohorts, while in adverse conditions only a single cohort occurred and under extreme conditions reproduction was skipped entirely. During the extended breeding season, larger males participated in reproduction throughout the breeding period, while smaller males appeared in later cohorts. Breeding success was related to the calling effort of a male, where larger males had greater mating success than smaller ones. We found that the natterjack toad males exhibit significant plasticity in reproductive behaviour at the northern range limit, which, given the energetic cost of reproduction and the increased risk of predation, allows them to increase their fitness at high latitudes.

Temperature regulation in lizards: effects of hypoxia

1985 ◽  
Vol 248 (5) ◽  
pp. R595-R600 ◽  
Author(s):  
J. W. Hicks ◽  
S. C. Wood
Keyword(s):  
Body Temperature ◽  
Temperature Regulation ◽  
Adaptation To Hypoxia ◽  
Metabolic Demand ◽  
Reduced Body ◽  
Life Saving ◽  
Preferred Body Temperature ◽  
Rate Of Cooling ◽  
Temperature Exposure ◽  
Hypoxic Gas Mixture

Temperature regulation during external (lowered lung PO2) and internal hypoxia (anemia) was examined in four species of lizards. Exposure to a hypoxic gas mixture in a thermogradient resulted in the animals lowering their selected (preferred) body temperature. A 50% reduction in the O2 carrying capacity of the blood also reduced the selected body temperature. Lizards "shuttle" when forced to select a temperature either above or below their normal selected temperature. Exposure to hypoxia decreases the upper and lower exit temperatures during shuttling. Furthermore, a decrease in the inspired O2 causes the rate of heating to no longer exceed the rate of cooling as is normal. The behavioral reduction of body temperature and the altered neural and physiological aspects of temperature regulation appear to be generalized responses to impaired O2 transport and not PO2 per se. The reduced body temperature, by lowering metabolic demand, provides an effective, even life-saving, adaptation to hypoxia.

scholarly journals Frontier mutualism: coevolutionary patterns at the northern range limit of the leaf-cutter ant–fungus symbiosis

2011 ◽  
Vol 278 (1721) ◽  
pp. 3050-3059 ◽  
Author(s):  
Ulrich G. Mueller ◽  
Alexander S. Mikheyev ◽  
Scott E. Solomon ◽  
Michael Cooper
Keyword(s):  
Range Limits ◽  
Peripheral Populations ◽  
Range Limit ◽  
Long Distance ◽  
Dispersal Barrier ◽  
The Andes ◽  
Genetic Patterns ◽  
Northern Range Limit ◽  
Traditional Assumption ◽  
Ant Fungus

Tropical leaf-cutter ants cultivate the fungus Attamyces bromatificus in a many-to-one, diffuse coevolutionary relationship where ant and fungal partners re-associate frequently over time. To evaluate whether ant– Attamyces coevolution is more specific (tighter) in peripheral populations, we characterized the host-specificities of Attamyces genotypes at their northern, subtropical range limits (southern USA, Mexico and Cuba). Population-genetic patterns of northern Attamyces reveal features that have so far not been observed in the diffusely coevolving, tropical ant– Attamyces associations. These unique features include (i) cases of one-to-one ant– Attamyces specialization that tighten coevolution at the northern frontier; (ii) distributions of genetically identical Attamyces clones over large areas (up to 81 000 km 2 , approx. the area of Ireland, Austria or Panama); (iii) admixture rates between Attamyces lineages that appear lower in northern than in tropical populations; and (iv) long-distance gene flow of Attamyces across a dispersal barrier for leaf-cutter ants (ocean between mainland North America and Cuba). The latter suggests that Attamyces fungi may occasionally disperse independently of the ants, contrary to the traditional assumption that Attamyces fungi depend entirely on leaf-cutter queens for dispersal. Peripheral populations in Argentina or at mid-elevation sites in the Andes may reveal additional regional variants in ant– Attamyces coevolution. Studies of such populations are most likely to inform models of coextinctions of obligate mutualistic partners that are doubly stressed by habitat marginality and by environmental change.

Living on the edge: Fig tree phenology at the northern range limit of monoecious Ficus in China

2014 ◽  
Vol 57 ◽  
pp. 135-141 ◽  
Author(s):  
Lu-Shui Zhang ◽  
Stephen G. Compton ◽  
Hui Xiao ◽  
Qian Lu ◽  
Yan Chen
Keyword(s):  
Range Limit ◽  
Tree Phenology ◽  
Northern Range Limit ◽  
Fig Tree

scholarly journals Variable habitat selection and movement patterns among Bullsnake (Pituophis catenifer sayi) populations in Saskatchewan

2019 ◽  
Vol 132 (2) ◽  
pp. 126-139 ◽  
Author(s):  
Tera L. Edkins ◽  
Christopher M. Somers ◽  
Mark C. Vanderwel ◽  
Miranda J. Sadar ◽  
Ray G. Poulin
Keyword(s):  
Habitat Selection ◽  
Radio Telemetry ◽  
Geographic Location ◽  
Space Use ◽  
Fine Scale ◽  
Range Limit ◽  
Northern Range Limit ◽  
Range Overlap ◽  
Conservation Concern ◽  
River Valleys

Pituophis catenifer sayi (Bullsnake) is a sparsely studied subspecies of conservation concern in Canada. Basic ecological information is lacking for P. c. sayi, which reaches its northern range limit in western Canada. To address this gap, we used radio-telemetry to examine space use and habitat selection in three populations of Bullsnakes in disjunct river valley systems (Frenchman, Big Muddy, and South Saskatchewan River Valleys) across their Saskatchewan range. Bullsnakes in two valleys used up to three times more space, travelled 2.5-times farther from overwintering sites, and had lower home range overlap than the third population. Landscape-level habitat selection was flexible, with snakes in all populations using both natural and human-modified habitats most frequently. Fine-scale habitat selection was also similar among populations, with Bullsnakes selecting sites within 1 m of refuges, regardless of whether they were natural or anthropogenic. Based on these results, Bullsnakes are flexible in their broad scale habitat use, as long as they are provided with fine scale refuge sites. The distribution of key seasonal resources appears to ultimately determine space use and habitat selection by Bullsnakes, regardless of the geographic location of the population.

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