Body temperature and above‐ground patterns during hibernation in European hamsters (<i>Cricetus cricetus</i> L.)

Wassmer, Thomas

doi:10.1017/s0952836903004643

Cited by 25 publications

(15 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Surprisingly, females in 2006 had a shorter postbreeding period and consequently a shorter active season. During the postbreeding period, females have to build up body fat reserves and food stores to survive over winter (Wassmer 2004;Weinhold and Kayser 2006;Franceschini-Zink and Millesi 2008). Common hamsters can use both strategies, allowing a more flexible preparation for hibernation and a less strict annual schedule compared to non-caching hibernators (Millesi et al 2004).…”

Section: Discussionmentioning

confidence: 99%

Seasonal constraints and reproductive performance in female Common hamsters (Cricetus cricetus)

2011

View full text Add to dashboard Cite

a b s t r a c tCommon hamsters (Cricetus cricetus) are hibernators and therefore show a pronounced seasonal breeding behaviour. Previous studies suggest that an early onset of reproduction after vernal emergence can be crucial for reproductive success in the current year. In Vienna, the winter 2005/06 was exceptionally cold and snow cover lasted until late March. This enabled us to investigate the effects of harsh winter conditions on seasonal timing and reproductive success in female Common hamsters. We investigated differences in the timing of the active season, reproductive performance and physical condition before hibernation between 2006 and previous years (2003-05) to determine potential environmental effects. Hamsters were live-trapped throughout the active period, weighed, individually marked and reproductive status was determined. The number of litters per season and litter size were determined in individual females. Vernal emergence in 2006 was considerably delayed and females mated significantly later than in 2003-05. Reproductive output in 2006 was about half that of the preceding years. This was particularly pronounced in the size of the females' first litters per season. The number of litters per female was similar in all periods. Almost 90% of the females in 2006 mated shortly after parturition and overlapped lactation of the first and gestation of the second litter. In 2003-05, only about one-third of the focal females successfully produced a litter after a postpartum oestrus. The time delay in spring 2006 led to a shorter active season compared to previous years reflecting the time constraints in this species. In conclusion, the results demonstrate that environmental factors can affect seasonal timing, reproductive output and preparation for hibernation in female Common hamsters.

show abstract

Section: Discussionmentioning

confidence: 99%

Seasonal constraints and reproductive performance in female Common hamsters (Cricetus cricetus)

2011

View full text Add to dashboard Cite

show abstract

“…Additionally, hamsters may not be an ideal model for hibernation, since they are not obligate hibernators and may only spend about half of their time during the hibernation season actually in torpor (i.e. Ueda and Ibuka, 1995;Wassmer, 2004).…”

Section: Discussionmentioning

confidence: 99%

Bone strength is maintained after 8 months of inactivity in hibernating golden-mantled ground squirrels, Spermophilus lateralis

Utz

Nelson

O’Toole

et al. 2009

Journal of Experimental Biology

View full text Add to dashboard Cite

SUMMARYProlonged inactivity leads to disuse atrophy, a loss of muscle and bone mass. Hibernating mammals are inactive for 6-9 months per year but must return to full activity immediately after completing hibernation. This necessity for immediate recovery presents an intriguing conundrum, as many mammals require two to three times the period of inactivity to recover full bone strength. Therefore, if hibernators experience typical levels of bone disuse atrophy during hibernation, there would be inadequate time available to recover during the summer active season. We examined whether there were mechanical consequences as a result of the extended inactivity of hibernation. We dissected femur and tibia bones from squirrels in various stages of the annual hibernation cycle and measured the amount of force required to fracture these bones. Three groups were investigated; summer active animals were captured during the summer and immediately killed, animals in the 1 month detraining group were captured in the summer and killed following a 1-month period of restricted mobility, hibernating animals were killed after 8 months of inactivity. A three-point bend test was employed to measure the force required to break the bones. Apparent flexural strength and apparent flexural modulus (material stiffness) were calculated for femurs. There were no differences between groups for femur fracture force, tibia fracture force, or femur flexural strength. Femur flexural modulus was significantly less for the 1 month detraining group than for the hibernation and summer active groups. Thus, hibernators seem resistant to the deleterious effects of prolonged inactivity during the winter. However, they may be susceptible to immobilization-induced bone loss during the summer.

show abstract

“…Previous studies demonstrated a high individual variation in hibernation patterns under semi-natural and laboratory conditions (Wassmer 2004; Wassmer and Wollnik 1997; Wollnik and Schmidt 1995). In some individuals, T b patterns during winter resembled those of obligate hibernators.…”

Section: Introductionmentioning

confidence: 98%

Torpor patterns in common hamsters with and without access to food stores

Siutz

Millesi

2017

J Comp Physiol B

View full text Add to dashboard Cite

Hibernating species significantly reduce energy expenditure during winter by entering torpor. Nevertheless, the various benefits of hibernation might be counteracted by negative effects of torpor such as immune depression, oxidative stress, or neuronal impairment. Considering these trade-offs, adequate energy reserves could allow animals to reduce the time spent in torpor or the extent of metabolic depression. Common hamsters use food stores during hibernation and previously documented high individual variations in body temperature patterns during winter could, therefore, be related to differences in external energy reserves. In this study, we manipulated the availability of food stores under laboratory conditions to investigate potential effects on hibernation patterns. Female hamsters were kept in artificial burrows in climate chambers and subcutaneous temperature was recorded using implanted data loggers. One group had access to large food stores, whereas another group received daily food portions which were removed on the next day if not consumed. Almost all hamsters without access to food stores hibernated, while less than half of the individuals with food stores entered deep torpor. Individuals without food hoards additionally expressed more short torpor bouts and exhibited lower minimum subcutaneous temperatures during torpor than those with food stores. Thus, individuals confronted with lacking food reserves were more likely to hibernate and additionally saved energy by entering short torpor bouts more frequently and remaining at lower subcutaneous temperature both during torpor and euthermic periods. In conclusion, our results demonstrate that food store availability affects torpor expression and also highlight variation in torpor patterns and energy-saving strategies in common hamsters.

show abstract

Body temperature and above‐ground patterns during hibernation in European hamsters (Cricetus cricetus L.)

Cited by 25 publications

References 11 publications

Seasonal constraints and reproductive performance in female Common hamsters (Cricetus cricetus)

Seasonal constraints and reproductive performance in female Common hamsters (Cricetus cricetus)

Bone strength is maintained after 8 months of inactivity in hibernating golden-mantled ground squirrels, Spermophilus lateralis

Torpor patterns in common hamsters with and without access to food stores

Contact Info

Product

Resources

About