Determinants and modeling of specific dynamic action for the Common Garter Snake (Thamnophis sirtalis)

2010 ◽  
Vol 88 (8) ◽  
pp. 808-820 ◽  
Author(s):  
Scott M. Bessler ◽  
Mary C. Stubblefield ◽  
G. R. Ultsch ◽  
Stephen M. Secor
Keyword(s):  
Oxygen Consumption ◽  
Body Temperature ◽  
Body Mass ◽  
Metabolic Response ◽  
Specific Dynamic Action ◽  
Meal Size ◽  
Garter Snake ◽  
Thamnophis Sirtalis ◽  
Dynamic Action ◽  
The Common

Specific dynamic action (SDA), the cumulative energy expended on digestion and assimilation, can contribute significantly to individual daily energy expenditure (DEE). The Common Garter Snake (Thamnophis sirtalis (L., 1758)) is a widely distributed generalist predator that could experience considerable variation in SDA and hence the contribution of SDA to DEE. We examined the effects of meal size, meal type, and body temperature on the postprandial metabolic response and SDA of the Eastern Garter Snake ( Thamnophis sirtalis sirtalis (L., 1758)) and generated predictive models of SDA based on meal size, body mass, and body temperature, and separately based on meal energy. Postprandial peak in oxygen consumption, duration of significantly elevated oxygen consumption, and SDA increased with increasing meal size (5%–45% of body mass). Postprandial metabolic response digesting six different equal-size prey items varied significantly; vertebrate prey generated larger SDA responses than soft-bodied invertebrates. Increases in experimental temperature (15–35 °C) yielded a matched increase in postprandial peak in oxygen consumption and decrease in digestive duration. For a 1-month hypothetical feeding history for an adult T. sirtalis, the cumulative predicted SDA varied by 4.5% among the three models (minimal, intermediate, and maximal intake of prey) and averaged 8%, 22%, and 38% of DEE, respectively.

Predation on fish and intersite variation in the diet of common garter snakes, Thamnophis sirtalis, on Vancouver Island

1991 ◽  
Vol 69 (4) ◽  
pp. 988-994 ◽  
Author(s):  
Patrick T. Gregory ◽  
Kari J. Nelson
Keyword(s):  
Temporal Variation ◽  
Body Mass ◽  
Vancouver Island ◽  
Garter Snake ◽  
Prey Abundance ◽  
Thamnophis Sirtalis ◽  
Garter Snakes ◽  
Site Specific ◽  
The Common

Diets of garter snakes (Thamnophis) often vary in space or time in response to variations in prey abundance. We compared the diet of the common garter snake (T. sirtalis) on Vancouver Island at fish-rearing facilities (hatcheries) and at nearby natural sites where fish were present but less abundant. Snakes of all sizes fed on fish at hatcheries, but fish were rarely eaten at natural sites, where amphibians or earthworms were the major prey types. Any particular characterization of the diet of this species therefore must be site specific. Although snakes exhibited intersite variation in diet, there was no evidence of temporal variation in diet at any site. The proportion of snakes with food in their stomachs varied among sites (perhaps indicating differences in frequency of feeding among sites) and was correlated with mean relative body mass of snakes. This suggests that some sites are more productive than others for snakes, but rigorous tests of whether snake populations are food-limited have not been done.

Effects of meal size, meal type, and body temperature on the specific dynamic action of anurans

2006 ◽  
Vol 177 (2) ◽  
pp. 165-182 ◽  
Author(s):  
Stephen M. Secor ◽  
Jessica A. Wooten ◽  
Christian L. Cox
Keyword(s):  
Body Temperature ◽  
Specific Dynamic Action ◽  
Meal Size ◽  
Dynamic Action

scholarly journals The metabolic response of the Bradypus sloth to temperature

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5600 ◽  
Author(s):  
Rebecca Naomi Cliffe ◽  
David Michael Scantlebury ◽  
Sarah Jane Kennedy ◽  
Judy Avey-Arroyo ◽  
Daniel Mindich ◽  
...  
Keyword(s):  
Oxygen Consumption ◽  
Body Temperature ◽  
Energy Expenditure ◽  
High Power ◽  
Metabolic Response ◽  
Metabolic Responses ◽  
Metabolic Depression ◽  
Wide Range ◽  
Energetic Constraints ◽  
Power Costs

Poikilotherms and homeotherms have different, well-defined metabolic responses to ambient temperature (Ta), but both groups have high power costs at high temperatures. Sloths (Bradypus) are critically limited by rates of energy acquisition and it has previously been suggested that their unusual departure from homeothermy mitigates the associated costs. No studies, however, have examined how sloth body temperature and metabolic rate vary with Ta. Here we measured the oxygen consumption (VO2) of eight brown-throated sloths (B. variegatus) at variable Ta’s and found that VO2 indeed varied in an unusual manner with what appeared to be a reversal of the standard homeotherm pattern. Sloth VO2 increased with Ta, peaking in a metabolic plateau (nominal ‘thermally-active zone’ (TAZ)) before decreasing again at higher Ta values. We suggest that this pattern enables sloths to minimise energy expenditure over a wide range of conditions, which is likely to be crucial for survival in an animal that operates under severe energetic constraints. To our knowledge, this is the first evidence of a mammal provisionally invoking metabolic depression in response to increasing Ta’s, without entering into a state of torpor, aestivation or hibernation.

Sign in / Sign up

Export Citation Format

Share Document