Circannual rhythmicity in the hibernating ground squirrel Citellus lateralis under constant light and hyperthermic ambient temperature

Pengelley, Eric T.; Aloia, Roland C.; Barnes, Brian M.

doi:10.1016/0300-9629(78)90135-4

Cited by 22 publications

(11 citation statements)

References 22 publications

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“…12 The average body mass period (τ bm ) of animals exposed to high temperature was about 0.942 years, which was slightly longer than the period recorded in animals exposed to cold (0.906 years; TABLE 1). 9 Experiments with the same ground squirrel maintained for four consecutive years at 3°C, showed that body mass rhythm was phase-locked with H-A rhythm, 13 which was confirmed in other hibernators. However, it is possible to dissociate these rhythms.…”

Section: Body Mass and Hibernation-activity Cycles In Free-running Comentioning

confidence: 77%

“…Other criteria of the internal rhythm is temperature independence in the 0-34°C temperature range. 9 However, some data indicate relative temperature dependence of endogenous rhythms. 10,11 In the early 1960s, it became clear that hibernation in golden-mantled ground squirrel (Spermophilus lateralis) is not only the response to the adverse environmental temperature and lack of food, but is an internal rhythm expressed in a cyclic change of body mass with a period close to one year, even in the absence of decreased Tb.…”

Section: Body Mass and Hibernation-activity Cycles In Free-running Comentioning

confidence: 99%

“…On the other hand, H-A cycling failed to conform to the exogenous rhythm when unlocking was the result of an excessive shortening of the forced cycle (0.5 year) in the presence of sufficiently low temperature (7°C). 14 The effect of temperature on the period of different physiological circannual rhythms (body mass, H-A, reproduction, and food intake) in different species of ground squirrels, 9,[11][12][13][14][15][16][17][18] marmot, 19 chipmunk, 16 and dormice 10 are summarized in TABLE 1. The photoperiod applied is displayed in the second row of the TABLE 1.…”

Section: Body Mass and Hibernation-activity Cycles In Free-running Comentioning

confidence: 99%

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Some Components of Hibernation Rhythms

Živadinović

Marjanović

Andjus

2005

Annals of the New York Academy of Sciences

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At low ambient temperatures some small mammals drastically reduce their body temperature and enter a state of dormancy known as hibernation. They exhibit endogenous rhythms of heterothermy/homeothermy and body mass fluctuations with the period close to one year. At high ambient temperature only body mass cycling is expressed for almost one year as well. The effect of temperature on circannual periods of some biological rhythms in different hibernators in free-running conditions as well as the circaseptal character of the intrahibernation rhythm of periodic arousals are reviewed.

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Section: Body Mass and Hibernation-activity Cycles In Free-running Comentioning

confidence: 77%

Section: Body Mass and Hibernation-activity Cycles In Free-running Comentioning

confidence: 99%

Section: Body Mass and Hibernation-activity Cycles In Free-running Comentioning

confidence: 99%

See 1 more Smart Citation

Some Components of Hibernation Rhythms

Živadinović

Marjanović

Andjus

2005

Annals of the New York Academy of Sciences

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“…With regard to this problem, it has been demonstrated that the hibernation (heterothermy) and body weight cycles in several species of ground squirrels (Citellus) persist for several years under constant environmental conditions, although the cycles were a little affected by some special environmental factors (Pengelley & Fisher, 1963;Pengelley & Kelly, 1966;Pengelley, 1967;Pengelley & Asmundson, 1969;Heller & Poulson, 1970;Pengelley, Asmundson et aE.,1976;Pengelley, Aloia et at., 1978). Pengelley (1967) considered that the cycles were governed by an endogenous rhythm of approximately a year's duration and proposed that such rhythm should be referred to as "circannian" or "circannual rhythm".…”

Section: Circannual Rhythm Of Body Weightmentioning

confidence: 99%

Annual cycles of body weight in the Namie's frosted bat, Vespertilio superans superans

Funakoshi

Uchida

1982

Journal of Zoology

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In order to elucidate the circannual cycles of fat deposition and depletion in hibernating bats, annual rhythm of body weight was examined in Vespertilio superans superans under a variety of environmental conditions. Under near natural conditions, adult females put on weight rapidly from October to November. The laboratory born subadult females kept in constant darkness at warm temperature gained weight at the same time as the adults. The length of weight cycle was about 10 months in adult females kept in 14 L : 10 D at about 24°C. These results suggest that cycles of fat deposition and loss are controlled by a modifiable endogenous circannual rhythm. Body weight rhythm persisted normally under warmer environmental conditions preventing the bats from hibernation. It is considered that the circannual cycles of fat gain and loss are relatively stable and not dependent on the hibernation cycle. Prolonged gestation period and delayed beginning of lactation by cold environment in summer did not affect the body weight rhythm. Temperature may be a more important environmental stimulus (or Zeitgeber) for the circannual rhythm than light and its effects may vary with phases.

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“…For example, the relationship between phenology and environmental variability is recognized as a key concern; however, largely overlooked is the extent to which phenological adjustments are regulated by biological time-keeping mechanism and circannual clocks, and the degree of flexibility built into these clockworks [25,34]. This may be of particular importance in hibernating mammals, where studies have shown the critical role of a relatively rigid, endogenous circannual clock in the persistence and timing of annually recurring seasonal events [25,35]. In AGS this may limit their ability to respond to a changing environment, particularly adult males [20].…”

Section: Breeding Phenologymentioning

confidence: 99%

Autumn conditions as a driver of spring phenology in a free-living arctic mammal

Sheriff

Buck

Barnes

2015

Clim Chang Responses

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Background: Several studies have shown that birds and mammals are breeding earlier in response to earlier spring conditions. Delay in the onset of winter should also affect reproductive timing and may allow for breeding later instead of earlier in spring, if extended autumns lengthen the season that food is available to offspring. Using 4 years of fine-scale environmental and phenological data of annual timing of hibernation and reproduction in two free-living populations of arctic ground squirrels in Northern Alaska, we show that the onset of winter snow-cover may influence females' spring phenology via its interaction with the timing of hibernation of young-of-the-year (YoY). Results: At the Atigun site, snowmelt occurs 26 days earlier and snow-cover occurs 14 days later than at the Toolik site. Previously, we found that Atigun females emerged and bred earlier than those at Toolik; however, here we show that this shift is not equivalent in magnitude to the earlier timing of spring conditions. At Atigun, females emerged and bred 13 days prior to snowmelt, while those at Toolik emerged and bred 34 days prior to snowmelt. We also found, importantly, that YoY entered hibernation after a set amount of time from birth regardless of site or environmental conditions. This resulted in Atigun YoY entering hibernation 24 (females) and 12 (males) days before snow-cover, but those at Toolik entering hibernation 0 (females) days before and 9 (males) days after snow-cover.This may allow females at Atigun to breed later (relative to snowmelt) in spring but select for early emergence and breeding of females at Toolik to allow sufficient time for offspring growth and preparation for hibernation. Conclusions: These results indicate that autumn conditions may influence subsequent spring phenology and changes in spring conditions may be only one factor influencing phenological shifts associated with climate change. We suggest that in areas with harsh spring conditions, such as the Arctic, animals may not shift their phenology to match earlier, but still unfavorable spring conditions, but may delay their timing of spring breeding if climate change also delays the onset of snow-cover, allowing sufficient timing for offspring growth and preparation prior to winter.

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Circannual rhythmicity in the hibernating ground squirrel Citellus lateralis under constant light and hyperthermic ambient temperature

Cited by 22 publications

References 22 publications

Some Components of Hibernation Rhythms

Some Components of Hibernation Rhythms

Annual cycles of body weight in the Namie's frosted bat, Vespertilio superans superans

Autumn conditions as a driver of spring phenology in a free-living arctic mammal

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