Effects of temperature on the duration of arousal episodes during hibernation

French, Alan R.

doi:10.1152/jappl.1982.52.1.216

Cited by 54 publications

(22 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Although the physiological need for periodic arousals is not well understood, this inverse relationship is common in bats and other hibernators (French 1982;Twente et al 1985;Geiser and Kenagy 1988). On average, female Indiana bats exhibited torpor bout durations of approximately 10 d at 4Њ-6ЊC.…”

Section: Discussionmentioning

confidence: 99%

Winter Energetics of Female Indiana Bats Myotis sodalis

Day

Tomasi

2014

Physiological and Biochemical Zoology

View full text Add to dashboard Cite

Understanding physiological limits and environmental optima is critical to developing protection strategies for endangered and threatened species. One theory to explain the decline in endangered Indiana bat Myotis sodalis populations involves increasing cave temperatures in winter hibernacula. Altered cave temperatures can raise metabolism and cause more arousals in torpid bats, both of which use more fat reserves. In addition, fluctuations in cave temperatures may cause additional arousals. Our objectives were to quantify the effect of temperature and fluctuations thereof on torpid metabolism and arousal frequency in this species. Female Indiana bats (n=36) were collected from caves just before hibernation, maintained in an environmental chamber that simulated hibernacula conditions, and had skin temperature recorded every 30 min throughout the winter. One environmental chamber containing bats (n=12) was sequentially set at 8°, 6°, and 4°C over the winter. The second chamber containing bats (n=12) experienced the same mean temperatures, but temperature fluctuated ±2°C on a regular basis. Torpor bouts were longest at 4°C and were not affected by temperature fluctuations. However, the temperature fluctuations appeared to cause longer arousals. Other bats (n=12) were individually placed in metabolic chambers to calculate oxygen consumption during torpor and during arousals. Torpid metabolism was affected by temperature; at 9°C, it was higher than at 7° or 5°C. Metabolism during arousals was not different among temperature treatments, but rates were almost 200 times higher than torpid metabolic rates. We calculated a winter energy budget and, from the energetic perspective, determined an optimum hibernation temperature (3°-6°C) for female Indiana bats. These findings suggest that hibernacula that provide these conditions deserve extra protection, although other factors in addition to energetics may play a role in temperature preferences.

show abstract

Section: Discussionmentioning

confidence: 99%

Winter Energetics of Female Indiana Bats Myotis sodalis

Day

Tomasi

2014

Physiological and Biochemical Zoology

View full text Add to dashboard Cite

show abstract

“…Since torpor bout duration seems to be linked to energy turnover in the hibernating state (27,29,31), minimizing the lowest tolerated body temperature, and hence metabolism, by establishing high n-6/n-3 ratios in heart phospholipids would also explain their effect on the length of torpor bouts. Alternatively, torpor bout duration may be directly affected by the impact of high n-6 to n-3 ratios on heart SERCA activity.…”

Section: Implications and Trade-offsmentioning

confidence: 99%

Effects of polyunsaturated fatty acids on hibernation and torpor: a review and hypothesis

Ruf¹,

Arnold²

2008

American Journal of Physiology-Regulatory, Integrative and Comp

140

134

View full text Add to dashboard Cite

Polyunsaturated fatty acids (PUFAs) can have strong effects on hibernation and daily torpor in mammals. High dietary PUFA contents were found to increase proneness for torpor, decrease body temperatures, prolong torpor bout duration, and attenuate hibernation mass loss. The mechanism by which PUFAs enhance torpor and hibernation is unknown, however. On the basis of a review of the literature, and on reexamining our own data on alpine marmots, we propose that effects on hibernation are not due to PUFAs in general, but to shifts in the ratio of n-6 PUFAs to n-3 PUFAs in membrane phospholipids. Specifically, high ratios of n-6 to n-3 PUFAs increase the activity of the Ca2+-Mg2+ pump in the sarcoplasmic reticulum of the heart (SERCA) and counteract Q10 effects on SERCA activity at low tissue temperatures. Therefore, high n-6 to n-3 PUFA ratios in cardiac myocyte membranes appear to protect the hibernating heart from arrhythmia, which in hypothermic nonhibernators is caused by massive increases in cytosolic Ca2+. The resulting reduced risk of cardiac arrest during hypothermia may explain why increased dietary uptake of n-6 PUFAs, but not of n-3 PUFAs, can strongly enhance the propensity for hibernation, and allows heterotherms to reach lower body temperatures, with associated increased energy savings. Therefore, at least for herbivorous hibernators, such as marmots, linoleic acid (C18:2 n-6)--the dietary source of all n-6 PUFAs--appears to represent a crucial and limited resource in natural environments.

show abstract

“…Hibernators arouse more rapidly when housed at elevated ambient temperatures (French, 1982). Thus, the waxing and waning pattern observed for RRW may be dependant on a relative rather than absolute amount of time.…”

Section: Relative Time Indexmentioning

confidence: 95%

“…it takes longer to rewarm from 4° C to ∼ 36° C than from 16° C to ∼ 36° C; e.g. French, 1982). In order to compare arousal dynamics across varying T a , the initiation and termination of an arousal must be clearly defined.…”

Section: A Relative Definition Of Arousalmentioning

confidence: 99%

See 1 more Smart Citation

Temporal and temperature effects on the maximum rate of rewarming from hibernation

Utz¹,

Velickovska²,

Shmereva³

et al. 2007

Journal of Thermal Biology

View full text Add to dashboard Cite

During hibernation animals oscillate from near ambient (T a ) to euthermic body temperatures (T b ). As animals arouse, the rate of rewarming (RRW) might be expected to simply increase as a function of time. We monitored the T b of golden-mantled ground squirrels (Spermophilus lateralis) housed at 4, 8, 12, and 16° C during natural arousals. The maximum RRW, the time required to reach a maximum RRW, and the relative time index all demonstrated negative relationships with T a . The T b corresponding to maximal RRW demonstrated a positive relationship with T a . Squirrels reached maximal RRW when they had generated 30 to 40% of the heat required to reach a euthermic T b . These data suggest that arousal is more constrained than expected and that both time and temperature influence the RRW.

show abstract

Effects of temperature on the duration of arousal episodes during hibernation

Cited by 54 publications

References 0 publications

Winter Energetics of Female Indiana Bats Myotis sodalis

Winter Energetics of Female Indiana Bats Myotis sodalis

Effects of polyunsaturated fatty acids on hibernation and torpor: a review and hypothesis

Temporal and temperature effects on the maximum rate of rewarming from hibernation

Contact Info

Product

Resources

About