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Hibernation is associated with long lifespan: on average, hibernating mammals live 15% longer than nonhibernators of equivalent mass. We investigated how survival varies with sex, season, and the deployment of biologgers in arctic ground squirrels (Urocitellus parryii (Richardson, 1825)), a widely distributed northern hibernator. The duration of hibernation in arctic ground squirrels differs markedly by sex: females hibernate 30% longer each year than males, a behavioural trait that could positively affect female survival. Additionally, males engage in aggressive territorial and food cache defense in spring and fall, which may decrease survival in this sex. From 13 years of mark-recapture data, we estimated apparent survival of arctic ground squirrels in Arctic Alaska (USA) using Cormack-Jolly-Seber models in program MARK. We found that females had higher annual survival ( Key words: survival, lifespan, hibernation, biologging, arctic ground squirrel, Cormack-Jolly-Seber modeling, demographics, Urocitellus parryii. L'hibernation est associee a la duree de vie : en moyenne, les mammiferes qui hibernent vivent 15 % plus longtemps que les mammiferes de masse semblable qui n'hibernent pas. Nous examinons les variations de la survie en fonction du sexe, de la saison et du deploiement de capteurs de parametres biologiques chez le spermophile arctique (Urocitellus parryii (Richardson, 1825)), un mammifere nordique hibernant caracterise par une vaste repartition geographique. La duree de l'hibernation des spermophiles arctiques differe considerablement selon le sexe : les femelles hibernant 30 % plus longtemps chaque annee que les males, un caractere comportemental qui pourrait avoir une incidence positive sur la survie des femelles. En outre, les males s'adonnent a la defense agressive de leur territoire et de leurs caches de nourriture au printemps et a l'automne, ce qui peut reduire la survie chez ce sexe. A la lumiere de 13 annees de donnees de marquagerecapture, nous estimons le taux de survie apparent de spermophiles arctiques en Alaska arctique (Etats-Unis) en utilisant des modeles de Cormack-Jolly-Seber dans le programme MARK. Nous constatons que les femelles ont un plus haut taux de survie annuel ([[^.[phi].sub..sup.nnuel] = 0,753 (l'intervalle de confiance (IC) de 95 % : 0,469, 0,913)) que les males ([[^.phi].sup.annual.sub.M] = 0,546 (IC de 95 % : 0,416, 0,670)) et une duree de vie maximum observee (10 ans) plus grande que celle des males (6 ans). Nous demontrons egalement que l'utilisation et l'implantation de capteurs de parametres biologiques n'a pas d'impact significatif sur la survie. La quantification de parametres demographiques de base des spermophiles arctiques a la lumiere de cette population bien etudiee illustre l'influence que peuvent avoir les variations selon le sexe de parametres associes a l'hibernation sur les differences de duree de vie des spermophiles arctiques males et etaie l'argument voulant que les appareils d'enregistrement de parametres biologiques soient securitaires. [Traduit par la Redaction] Mots-cles: survie, duree de vie, hibernation, enregistrement de parametres biologiques, spermophile arctique, modelisation Cormack-Jolly-Seber, demographie, Urocitellus parryii., Introduction Hibernation is a strategy used by diverse species of mammals to survive prolonged resource scarcity (Geiser 1998; Staples 2016) and is associated with long lifespan: Turbill et al. (2011) [...]

Duration of torpor by eastern chipmunks, Tamias striatus, kept at 5 degrees C progressively increased at the beginning of hibernation (autumn phase), remained long and relatively constant (winter phase), and then decreased (spring phase) in a fashion similar to that observed in hibernators that store energy as body fat. Duration of bouts of torpor in winter and spring and amount of time animals hibernated before starting the energetically demanding spring phase were related inversely to amount of food provided at the beginning of the experiment. In addition, chipmunks given the least amount of food (400 g) continued to hibernate until they consumed all seeds; those provided with abundant food (5,000 g) terminated hibernation spontaneously early in the spring phase and remained euthermic thereafter. Animals given an intermediate ration (1,000 g) hibernated until food was gone (42%) or spontaneously terminated hibernation with abundant food uneaten (58%). Thermoregulatory responses of chipmunks appear more flexible than those of species that store energy as body fat, but the match between use and availability of energy during dormancy is imprecise.

White-nose syndrome (WNS) is an emerging disease affecting hibernating bats in eastern North America that causes mass mortality and precipitous population declines in winter hibernacula. First discovered in 2006 in New York State, WNS is spreading rapidly across eastern North America and currently affects seven species. Mortality associated with WNS is causing a regional population collapse and is predicted to lead to regional extinction of the little brown myotis (Myotis lucifugus), previously one of the most common bat species in North America. Novel diseases can have serious impacts on naive wildlife populations, which in turn can have substantial impacts on ecosystem integrity. 10.1126/science.1188594

The susceptibility of bats to a deadly disease is influenced by the humidity of the caves in which they hibernate. White-nose syndrome, which has killed millions of bats in North [...]

Studying hibernation could lead to better treatments for type 2 diabetes: New research shows that hibernating grizzly bears enter a state in which insulin, which prevents breakdown of body fat, [...]

Accumulation of urea in defense of body water is an adaptation present in a diverse array of ureotelic animals. Some authors have proposed that urea may contribute to a metabolic depression in hyperuremic animals which do not co-accumulate counteracting solutes, as is likely the case in estivating and terrestrially-hibernating amphibians. However, to our knowledge the direct metabolic effects of hyperuremia in dormant amphibians have never been tested. We used the wood frog, Rana sylvatica, a terrestrial hibernator which accumulates urea in winter, to examine the hypometabolic effect of physiological levels of urea at the whole animal and tissue levels. Compared to hydrated controls, mildly-dehydrated, winter-acclimated frogs had higher (p