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As revealed by allozyme studies, the genetic variation of the Alpine marmot (Marmota m. marmota) has been reduced by a species-wide bottleneck at the end of the last glaciation. Therefore the more variable microsatellite loci were used as a genetic marker system to investigate variablility and differentiation of four autochthonous and four allochthonous populations founded by the release of small numbers of individuals during the last 150 years. The microsatellite loci detected by the DNA-probe (ATCC)4 were found to be polymorphic in all populations, but the amount of variation was lower than in comparable mammalian species. In spite of founder effects the variation in the allochthonous populations was not significanlty reduced compared to the autochthonous populations. The autochthonous populations from Austria and from the eastern part of Switzerland were genetically similar, only the population from western Switzerland was clearly differentiated from the others. In the allochthonous populations similarities in the microsatellite patterns reveal genetic affinities to putative autochthonous source populations of the founder individuals.

We measured body temperatures in two large hibernating mammals, the eutherian alpine marmot (Marmota marmota) and the egg-laying echidna (Tachyglossus aculeatus) from unrestrained animals in their natural environment. In both species hibernation is broken every 13 days on average by rewarming to euthermic temperatures. We found that the time course of a rewarming could be closely fitted with a sigmoid curve, allowing calculation of peak rewarming rate and corresponding body temperature. Maximum rewarming rates were twice as high in marmots as in echidnas (12.1±1.3 °C h−1, n=10 cf. 6.2±1.2 °C h−1, n=10). Peak rewarming rates were positively correlated with body temperature in echidnas, but negatively correlated in marmots.

Microsatellite variation was studied in 11 populations of the Alpine marmot along a west–east transect through the present distribution range. The samples represent five autochthonous and six introduced populations. Eleven loci were analysed in nine populations and six loci in the two populations from France. In the populations from the Western Alps, there is no indication for reduced variability as has been assumed in previous studies. However, a decrease of variation in the autochthonous populations was observed from the west to the east. The introduced populations showed a heterogeneous pattern reflecting the geographic origin of the released individuals. The population from the Spanish Pyrenees harbours a high level of variation and is genetically closest to the French populations. In Austria, three of the introduced populations have low variation and are closely related to the autochthonous populations from the western part of Austria. In contrast, two introduced populations from the central part of Austria are highly variable and resemble the populations from France. At least for one of these populations an early introduction of founder individuals from the Western Alps has been documented. Zusammenfassung Die Mikrosatellitenvariation wurde in 11 Populationen des Alpenmurmeltieres entlang eines west-ost Gradienten durch das gegenwartige Verbreitungsgebiet untersucht. Die Stichproben reprasentieren funf autochthone und sechs eingeburgerte Populationen. Elf Loci wurden in neun Populationen analysiert und sechs Loci in den beiden Populationen aus Frankreich. In den Populationen aus den Westalpen ergab sich im Gegensatz zu fruheren Untersuchungen kein Hinweis auf eine Reduktion der Variabilitat. Innerhalb der autochthonen Populationen ist jedoch eine Abnahme der Variation von Westen nach Osten festzustellen. Die eingeburgerten Populationen zeigten ein uneinheitliches Muster, welches den geografischen Ursprung der ausgesetzten Individuen widerspiegelt. Die Population aus den spanischen Pyrenaen besitzt eine hohe Variation und ist genetisch den franzosischen Populationen am ahnlichsten. In Osterreich zeigen drei der eingeburgerten Populationen niedrige Variation und sind den autochthonen Populationen aus Westosterreich am nachsten verwandt. Hingegen sind die beiden eingeburgerten Populationen aus Zentralosterreich hoch variabel und den Populationen aus Frankreich ahnlich. Zumindest fur eine dieser beiden Populationen ist eine fruhe Einburgerung von Grunderindividuen aus den Westalpen dokumentiert.

In social species, the hierarchical status of an individual has important consequences for its fitness. While many studies have focused on individual condition to explain access to dominance, very few have investigated the influence of the social environment, especially during early life. Yet it is known that environmental conditions early in life may influence several traits at adulthood. Here, we examine the influence of early social environment on accession to dominance by investigating the influence of litter size and sex composition on survival and the probability of ascending to dominance later in life using a 20-year dataset from a wild population of Alpine marmots (Marmota marmota). Although litter size had no effect on the fate of individuals, litter sex composition affected male juvenile survival and both male and female probabilities of reaching dominant status when adult. Male juveniles incur lower survival when the number of male juveniles in the litter increases, and individuals of both sexes from male-biased litters are more likely to become dominant than individuals from female-biased litters. However, the absolute number of sisters in the litter, rather than the sex ratio, seems to be an important predictor of the probability of acquiring dominant status: pups having more sisters are less likely to become dominant. Several potential mechanisms to explain these results are discussed.

Extra-pair paternity (EPP) can be influenced by both social setting and female mate choice. If evidence suggests that females try to obtain extra-pair copulations (EPCs) in order to gain genetic benefits when mated to a homozygous and/or to a related male, females may not be able to choose freely among extra-pair mates (EPMs) as the social mate may constrain female access to EPMs. In this study, we investigated, first, how EPP depended on social setting and specifically on the number of subordinate males in the family group in a highly social and monogamous mammal, the alpine marmot. Second, we investigated how EPP depended on female mate choice for genetic benefits measured as male mate-heterozygosity and within-pair relatedness. Our results reveal, first, that EPP depended on the social setting, increasing with the number of subordinate males. Second, EPPs were related to relatedness between mates. Third, EPMs were found to be more heterozygous than within-pair males. Thus, social setting may constrain female choice by limiting opportunities for EPC. However, after accounting for social confounding factors, female choice for genetic benefits may be a mechanism driving EPP in monogamous species.

Two hundred and six samples of alpine marmot (Mamota marmota) hair (148 from adults and 58 from young subjects), 102 soil samples from the entrances to the burrows of the above individuals and 20 control specimens (obtained from adjoining areas away from the burrow systems where the rodents are not usually present) were examined from May 1994 to September 1997. Seventy-five isolates belonging to six species of dermatophytes were found in 69 of the 206 hair samples examined (33.5%). Two species were zoophilic, Microsporum canis (7.8%) and Trichophyton mentagrophytes (11.2.%), and four geophilic, Microsporum cookei (2%), M. gypseum (5.8%), Trichophyton ajelloi (3.9%) and T. terrestre (5.8%). The prevalence of each species in the hair samples did not change significantly according to year, season (chi-squared test [limit significance: P 0.05] both in year and in season comparison) or age/sex (adult versus juvenile: P = 0.1; male versus female: P=0.8) of the marmot. Twen...

The consequence of helping behavior on breeders fitness is still controversial. We used multivariate analyses to investigate for the effects of male and female subordinates on breeders’ components of fitness in the Alpine marmot, Marmota marmota. We found that male and female subordinates, respectively, increased and decreased juvenile survival during winter. Thus, we give evidence that male subordinates should be considered as helpers, and that helpers provided breeders with immediate reproductive success gains, whereas subordinates females were costly. Helpers had no positive effects on female body condition, on persistence (future survival) of dominants, and on future reproduction (occurrence and size of a litter). Helpers thus did not provide breeders with delayed fitness benefits, and therfore, the load-lightening hypothesis was not supported. On the contrary, helpers had delayed fitness cost for dominant males and, consequently, for dominant females. Immediate benefits counterbalanced by delayed costs suggested an optimal number of helpers in the family group both from male and female perspectives. An optimality model well predicted the observed mean number of helpers in Alpine marmot family groups. Optimal numbers of helpers were slightly different for males and females, suggesting a potential conflict of interest between dominants. We finally discuss the possible mechanisms of helping that may explain the observed pattern in the Alpine marmot. Key words: cooperative breeding, loadlightening hypothesis, Marmota marmota, mixed models, optimality. [Behav Ecol 15:916–924 (2004)]

Circannual changes in serum parameters and body mass were studied in free-ranging Marmota marmota that had been shot in Switzerland (Grisons) for management reasons in May, July, and September of 1995, 1996, and 1997; and in April 1996. Markers of lipid (triglycerides, cholesterol), protein (total protein, urea-nitrogen) and mineral (calcium, inorganic phosphate) metabolism were evaluated in 111 haemolysis-free serum samples; the effects of sex, age, reproductive status, season and year were tested. Mean body mass was higher in adult males than in adult females in July and September, and serum cholesterol concentrations were lower in adult males in May. Pregnant females had lower concentrations of total protein than non-pregnant females, and triglyceride concentrations were negatively correlated with the number of uterine ampullae. Inorganic phosphate decreased and total protein increased with age. In adults, triglycerides, cholesterol and urea-nitrogen increased mainly from May to July and decreased between September and May. Total protein, calcium and phosphate did not change throughout the year. This suggests that, during the active season, ingested lipids and amino acids were utilised for metabolic needs or lipid storage, while in winter, lipids were catabolised and protein was spared. Quantitative differences between years, observed for triglycerides and total protein during the active season, were probably due to different climatic conditions in each year.

In cooperatively breeding vertebrate species, a clear theoretical prediction about the direction of sex ratio adjustment can be made: mothers should bias the sex ratio of their offspring towards the helping sex when helpers are absent. A consistent trend in the direction predicted by theory exists in cooperative birds, but theory is still poorly tested in cooperative mammals. Here, multivariate analyses are applied to a long-term data set to test this prediction in two ways in the alpine marmot: (1) across females in a population and (2) in individual females across multiple years. It was shown that in the alpine marmot offspring sex ratio was biased towards the helping sex (males) when helpers were absent, whereas helped mothers produced unbiased sex ratio. Unhelped mothers did not adjust the litter size but produced more sons and fewer daughters than helped mothers. These results support the theoretical prediction and explain well the male bias observed among juvenile alpine marmots at the population level. The occurrence of possible sex ratio manipulations in cooperatively breeding vertebrates is also discussed. Copyright 2004.

An alpine marmot's home range is a structured portion of soil, vegetation and rocky outcrops. The dynamics of home range and resource use were investigated in Marmota marmota L. at Gran Paradiso National Park, south-west Alps, Italy. Data were collected during 8 years from 73 individually known marmots, occupying three adjacent locations, in 264 hr of scanning and 551 hr of focal animal sampling. Three different locations did not differ in the total dimension of the home range but they differed in the total dimension of pasture. The home range inherited by immigrant monogamous couples supplanting the unrelated previous groups did not contract, and the dimension were not dictated by immediate feeding necessities, thus suggesting that in some way alpine marmots may envisage future needs. The main burrow systems and hibernacula were inherited by the new couples as well, while the spotting/resting points and other burrows varied across years and groups. The capability of the alpine marmots to maintain stable ...

A general rule of thumb for biological conservation obtained from simple models of hypothetical species is that for populations with strong environmental noise moderate increases in habitat size or quality do not substantially reduce extinction risk. However, whether this rule also holds for real species with complex behavior, such as social species with breeding units and reproductive suppression, is uncertain. Here we present a population viability analysis of the alpine marmot Marmota marmota, which displays marked social behavior, i.e. it lives in social groups of up to twenty individuals. Our analysis is based on a long-term field study carried out in the Bavarian Alps since 1982. During the first fifteen years of this study, 687 marmots were individually marked and the movements and fate of 98 dispersing marmots were recorded with radio-telemetry. Thus, in contrast to most other viability analyses of spatially structured populations, good data about dispersal exist. A model was constructed which is individual-based, spatially explicit at the scale of clusters of neighbouring territories, and spatially implicit at larger scales. The decisive aspect of marmot life history, winter mortality, is described by logistic regression where mortality is increased by age and the severity of winter, and decreased by the number of subdominant individuals present in a group. Model predictions of group size distribution are in good agreement with the results of the field study. The model shows that the effect of sociality on winter mortality is very effective in buffering environmental harshness and fluctuations. This underpins theoretical results stating that the appropriate measure of the strength of environmental noise is the ratio between the variance of population growth rate and the intrinsic rate of increase. The lessons from our study for biological conservation are that simple, unstructured models may not be sufficient to assess the viability of species with complex behavioral traits, and that even moderate increases in habitat capacity may substantially reduce extinction risk even if environmental fluctuations seem high.

We studied mechanisms responsible for reproductive skew in female Alpine marmots. In each social group, only dominant females produced weaned young although subordinate females had similar body condition, were fertile as indicated by high levels of oestradiol during the mating season, and occasionally started pregnancies. During the period of gestation, dominant females initiated significantly more agonistic interactions against subordinate females, resulting in significantly increased levels of glucocorticoids and decreased levels of progesterone in subordinates. Results suggested that reproductive suppression in female Alpine marmots is mediated by the negative effects of stress (glucocorticoids) on the activity of the hypothalamic-pituitary-gonadal axis. The strength of competition between subordinate and dominant females was affected by their relatedness. Dominant females attacked unrelated subordinate females more, whereas amicable behaviour was observed mainly between dominant females and their daughters. These differences could be explained by differences in indirect fitness: related subordinate females benefited from warming the offspring of the dominant female during hibernation. Reproductive suppression was apparently costly for dominant females, because their reproductive success decreased as the number of adult subordinate females in a group increased.  2003 Published by Elsevier Ltd on behalf of The Association for the Study of Animal Behaviour.

Yellow-bellied marmots (Rodentia: Sciuridae) typically hibernate for eight months. This study explored energetic costs of hibernation in young and adults at 10 and 6 degrees C. Age significantly affected the percent time torpid, total and mass-specific VO(2), use of energy during torpor, and daily mass loss at 6 degrees C. Thus young had a higher mass-specific VO(2) during a torpor bout, which was attributed to higher metabolism during deep torpor. Total VO(2) during a bout was higher in young and there were significant temperature/age interactions; young had a higher VO(2) during torpor and deep torpor at 6 degrees C than at 10 degrees C. VO(2) increased at T(E)s below 6 degrees C. Young had a higher daily mass loss than adults at 6 degrees C. Euthermy increased energetic costs 19.3 times over those of torpor and 23.5 times over those of deep torpor. Energy costs are minimized by spending 88.6% of the hibernation period in torpor, by the rapid decline of VO(2) from euthermy to torpor and by allowing T(B) to decline at low T(E). Torpidity results in average energy savings during winter of 83.3% of the costs of maintaining euthermy. Energy savings are greater than those reported for Marmota marmota and M. monax.

We examined the social, maternal, and environmental factors affecting the reproductive success of female Alpine marmots (Marmota marmota) during 8 years in the French Alps. Successful production of juveniles was almost entirely limited to dominant females. Production of juveniles increased with maternal body condition and experience. Female body condition was positively correlated with body mass and negatively correlated with dominant-male takeovers in spring, while experience increased with age. We found little evidence for a pregnancy block with takeover of dominant males because male replacement occurred mostly after mid-May, when juveniles were susceptible to infanticide. Production of yearlings depended on the number of juveniles produced, dominant-male takeovers in summer, and exposure of the site. We found no significant influence of group size or composition on production of yearlings. Climatic conditions varied little and had no measurable effect on reproduction. Social factors such as female dominance and dominant-male takeovers that could lead to infanticide have a strong effect on female reproductive success in Alpine marmots.

The gastrointestinal tracts of 76 free-living alpine marmots ( Marmota marmota) shot during a population control program in Switzerland were collected and analysed for patterns of change in morphology and function over the period from emergence from hibernation in April to just before re-entry into hibernation in September. Between first emergence and mid-summer (July) the fresh tissue mass of the stomach increased by 105%, the small intestine by 259% (among the largest recorded for a mammal), caecum by 185%, proximal colon by 138%, and distal colon by 144%. Mitotic activity was greatest in the small intestine; the mitotic index was high (40%) compared with indexes in the stomach and hindgut (approximately 4%) even at emergence, and increased to approximately 60% by mid-summer. Microbial activity in the caecum was also significant at emergence. The stomach (length) and caecum (length and fresh mass) increased in response to ingested food earlier than did the small intestine. Between mid-summer and September there were decreases in small intestinal tissue mass and mitotic activity. It is concluded that the gastrointestinal tract of alpine marmots probably continues to function throughout hibernation at a low level, with a mid-winter trough as part of an endogenous circannual rhythm. However, after emergence in spring, increases in size and activity of the tract appear to be a response to ingested food rather than to an endogenous signal. The early signs of down-regulation of the small intestine before re-entry into hibernation, together with its delayed up-regulation in response to food in spring, are consistent with the high costs of maintaining this section of the digestive system.

We examined the morphology of the wrist (carpal region) skeleton using histological serial sections and cleared and stained forelimbs of representatives of three rodent clades: ‘Hystricomorpha’ (Caviomorpha: Ctenomys opimus, C. talarum, Cuniculus taczanowskii, Erethizon dorsatum, Galea sp., Lagostomus maximus, Spalacopus cyanus; Phiomorpha: Fukomys mechowii, Heliophobius argenteocinereus, Hystrix cristata, H. africaeaustralis; Ctenodactylids (Ctenodactylus gundi)), ‘Myomorpha’ (Arvicola amphibius, Ondatra zibethicus, Meriones unguiculatus, Myodes glareolus, Spalax sp.) and ‘Sciuromorpha’ (Eliomys quercinus, Glis glis, Marmota marmota). We describe the arrangement of the carpal bones and identify several variable traits, some of which represent convergent evolution. One element, the Os posthamatum, lies in the carpal region and has not been recorded before. We interpret this bone as a putative autapomorphy of Hystricognathi but not of ‘Hystricomorpha’.

Historical sources documenting recurrent plagues of the “Second Pandemic” usually focus on urban epidemic mortality. Instead, plague persists in remote, rural hinterlands: areas less visible in the written sources of late medieval Europe. Plague spreads as fleas move from relatively resistant rodents, which serve as “maintenance hosts,” to an array of more susceptible rural mammals, now called “amplifying hosts.” Using sources relevant to plague in thinly populated Central and Western Alpine regions, this paper postulates that Alpine Europe could have been a region of plague persistence via its population of wild rodents, particularly the Alpine marmot.

This study took place in the Parco Nazionale del Gran Paradiso (P.N.G.P.), Valle d'Aosta, Italy, from 1985 to 1993 on an area of 200 ha, 52% of which was a suitable surface for marmot settling during summer. Density of hibernacula varied from 0.09 burrows per hectare in 1986, to 0.2 burrows per hectare in 1991, the year when the maximum density of hibernacula was found. The mean number of hibernacula across years was 14.37, and the mean density was 0.13 per hectare. Despite a fluctuation of 10–21 hibernacula found in the springtime, the number of permanent hibernacula increased from 10 to 13. All new hibernacula that became permanent appeared within empty territories, suggesting that at least a fraction of the annual dispersers hazarded to dig new hibernacula or readapt summer burrows. Above the timberline, animals at higher elevation emerged later than animals at lower elevations (GLM; df = 1,21; F = 18.41; P = 0.000). Seventy-one percent of the infants distributed in 14 litters were observed for the fir...

External daily activity was studied in the alpine marmot (Marmota marmota Linné, 1758) in its natural environment in relation to the position of the sun, ambient temperature, and food accessibility. At low temperatures, daily activity starts only when the sun reaches 30° or more above the horizon. During temperate periods, external daily activity is closely synchronized with the height of the sun (16°-17° above the horizon). However, on hot days the duration of surface activity of alpine marmots at the end of the day could be explained by the postponement of feeding when high and uncomfortable midday temperatures limit food accessibility. Our observations under natural conditions seem to indicate that several factors are involved in the synchronization of nyctemeral activity in the alpine marmot. The cycle of light, expressed as the height of the sun above the horizon, is the most important. However, marmots show different responses to light in the morning and at night. These results corroborate the circadian rhythm model with two oscillators.

In a French population of Alpine marmots (Marmota marmota), the sex ratio at weaning was biased in favor of males. This bias also seemed to exist at birth. Under Fisher’s equal allocation principle, this means that daughters should be more costly to produce than sons. Because the Alpine marmot can be considered a cooperative breeding species, we investigated whether the differential cost between sons and daughters may be explained by the helper repayment hypothesis. The Alpine marmot uses social thermoregulation during hibernation, allowing juveniles to better survive over winter. In the study population, juvenile survival during winter increased with group size. More precisely, juvenile survival during winter increased with the number and with the proportion of subordinate males in the hibernating group, but juvenile survival did not depend on the number of subordinate females. As our results did not support alternative hypotheses to explain the observed bias in sex ratio among offspring at emergence, we conclude that the helper repayment hypothesis is the best candidate to explain the observed offspring sex ratio bias in Alpine marmots. By participating in social thermoregulation, subordinate males may repay part of the investment they received from their parents and thus become less costly to produce. We suggest that only subordinate males helped because they may gain direct fitness benefits, whereas subordinate females may only expect indirect fitness benefits from helping. Finally, the offspring sex ratio per individual parent was male biased, but mothers adjusted the size and the sex composition of their litters according to their phenotypic condition as expected from the Trivers-Willard hypothesis. Key words: Alpine marmots, cooperative breeding, helper repayment hypothesis, Marmota marmota, sex ratios. [Behav Ecol 11:507–514 (2000)]

In the wild, Alpine marmots (Marmota marmota) spend most of their time in underground burrows. Thus the observation of reproduction biology during mating season, gestation, and the early juvenile development is extremely challenging. An ultrasonographic follow-up of pregnancies in captive alpine marmots illustrates the characteristic findings of different gestational phases. The first ultrasonographic proof for a pregnancy was detected on day -25 (day 0 defined as partus). At day -18, first heartbeats were visualized, followed by spontaneous fetal movements on day -14. At day -7, the mineralization of the skeletal system was demonstrated. It was possible to evaluate and monitor the integrity of pregnancy. Ultrasonography is a noninvasive, alternative tool to the classical verification of pregnancy in marmots by progesterone measurement from serum samples.

During winter, hibernating animals rely on their lipid stores for survival. In vitro lipolytic activity of isolated adipocytes from gonadal and subcutaneous white adipose tissue (WAT) was studied in captive alpine marmots (Marmota marmota) at two different times of their yearly cycle. During the summer, when marmots were eating, adipocyte responsiveness and sensitivity to isoprenaline and noradrenaline were higher in gonadal than in subcutaneous WAT. During hibernation, when marmots were spontaneously fasting. both the response and sensitivity to catecholamines decreased in gonadal WAT to the level of subcutaneous WAT. A similar pattern of response was also observed when lipolysis was stimulated with glucagon but the lipolytic rate was three times lower than with catecholamines. Adenosine deaminase (ADA) had a marked stimulatory effect on lipolysis, especially during the 'feeding' period, suggesting that adenosine may be a potent lipolytic modulator in marmot adipocytes. It is concluded that in marmots, lipolysis could be differentially regulated between fat depots during the annual cycle possibly to optimize either the building-up or the use of fat reserves.

This study took place in the Parco Nazionale del Gran Paradiso (P.N.G.P.) from 1981 to 1993. Most of the observations were made from early June to late September. Marmots inhabited the concavities of the valleys above the timberline and on slopes from 0° to 35° of a transect of 4200 ha. Density was estimated by animal counts in two sample areas and ranged from 0.6 to 1.5 an/ha. Population dynamics was investigated from 1985 to 1993 in a colony at 2350 m; 57 marmots were live trapped for individual recognition. The total number of sexually mature reproductive groups observed was 27, in 18.5% a trio made of two unrelated males and one female was present. Never were two adult females found together and never were two different litters found concurrently on the same territory. Male/female ratio for immigration was 1.8, G test P > 0.005. Mean group size not including infants was 4.7 ± 2.9, range 2–11. Social groups had the highest turnover rate ever reported for a colony of alpine marmots. A total of 60 infant...

We established the phylogeny of 11 species of the genus Marmota based on the entire sequence of the mitochondrial cytochrome b (cyt-b) gene (1.1 kb) and a partial sequence of the NADH dehydrogenase subunit 4 (ND4) gene (1.2 kb). In three species (Marmota caligata, Marmota olympus, and Marmota bobac) full-sized nuclear pseudogenes of the mitochondrial cyt-b were identified. The mitochondrial cyt-b genes and the three pseudogenes form separate clusters in the maximum parsimony dendrogram. This finding suggests that the pseudogenes originated from a single transfer to the nucleus that may have occurred prior to the radiation of the genus Marmota. Notably, compared with their functional mitochondrial equivalents the pseudogenes show a much lower substitution rate. In the dendrograms deduced from the mitochondrial sequences two distinct clusters become apparent: one cluster consists of the North-west American species, the other contains the Eurasian species together with the North American species Marmota monax. The position of M. monax as a member of the Eurasian clade is in accordance with the evolution of chromosome numbers. The results are of special interest with respect to the evolution of social systems in the genus that vary from solitary species (M. monax) to highly social species living in family groups (e.g. Marmota marmota). The molecular phylogeny suggests a diphyletic origin of high sociality in the genus Marmota.

Alpine marmots (Marmota marmota) were maintained on a laboratory diet, and the fatty acid composition of gonadal and subcutaneous white adipose tissues (WAT) was studied during a yearly cycle. Fatty acids (FA) released from isolated adipocytes were also identified after stimulation of in vitro lipolysis. Analysis of the FA composition of WAT depots showed that marmot WAT mainly contained monounsaturated FA (65%, mostly oleic acid, 18:1n-9) although laboratory food contained 45% of linoleic acid (18:2n-6) and only 21% of 18:1n-9. During stimulated lipolysis, saturated FA were preferentially released from isolated adipocytes whereas unsaturated FAs were retained. Despite this selective release of FA from isolated WAT cells in vitro, and despite the FA composition of the food, marmots maintained a constant FA composition in both WAT depots throughout the year. Six months of hibernation and fasting as well as an intense feeding period did not affect this composition. The potential adaptive benefit of such regulation of WAT composition, based on a high level of monounsaturated FA, might be to maintain fat with appropriate physical properties allowing animals to accommodate to and survive the wide range of body temperatures experienced during hibernation.

Many species produce alarm calls that vary according to situation. Theoretically, alarm call structure could covary with predator type and could communicate potentially ''referential information, or calls could covary with the degree of risk a caller experienced when it emitted a call. Using similar methods, I studied the ways in which Olympic (Marmota olympus), hoary (M. caligata), and Vancouver Island marmots (M. vancouverensis) communicated situational variation. I observed both natural alarm calling, and I artificially elicited alarm calls with simulated terrestrial and aerial predators. I used playback experiments to study marmots' responses to different alarm call variants. All three species produced four roughly similar but distinctive loud alarm vocalizations that could be categorized by their relative shape, duration, and whether calls were quickly repeated to create multi-note vocalizations. In addition, the Vancouver Island marmot produced a fifth loud alarm call-the kee-aw. Call micro-structure varied as a function of the distance the caller was from an alarming stimulus and the type of alarming stimulus. Two lines of evidence suggest that all three species had alarm calls associated with the caller's risk (i.e. they were not referential). First, marmots often changed call types within a calling bout: there were no unique stimulus-class specific vocalizations. Second, marmot responses to alarm calls were graded: marmots did not have unique responses to different call types. These three close taxonomic relatives with superficially similar calls, communicated risk differently.

The Alpine marmot Marmota marmota is a territorial rodent. Resident adults regularly scent-mark their territory by cheek-rubbing, mainly on burrow entrances and along boundaries. The purpose of this three part study was to gain further insight into this scent-marking behavior by: (1) observing the response of free-ranging marmots to foreign scent marks, (2) confirming the glandular source of the marking substance by histologic examination of the temporal gland, and (3) identifying biologically active chemical fractions of the marking substance. To allow field tests, we developed a device consisting of a glass tube placed upside down over a stake. Two devices were simultaneously placed at one burrow entrance. On one device, a clean tube was used and, on the other, a tube alternatively coated with either whole natural scent-marking substances or various fractions obtained by solvent extraction or chromatographic separation from whole scent-marking substances. Subsequent observations showed a significant difference in the duration of nose contact and number of cheek-rubbing movements. Resident adult marmots sniffed and marked tubes bearing alien marks significantly more than clean control tubes. Similar differences in behavior were observed with ethanol extracts of whole scent-marking substances. Extracts obtained with pentane and dichloromethane showed no bioactivity, suggesting that highly polar compounds are the active substances in the Alpine marmot. The temporal gland is an exocrine gland located on each side of the head with numerous pores opening at the surface of the skin in the cheek area. GC-MS analysis of individually collected samples from these glands showed that over 30 compounds were consistently present. Seven of these compounds were identified. Two fractions were obtained and used together and separately in field tests. Fraction 1 was composed mainly of short-chain alcohols and alkanes, and fraction 2 had a more acid and ester composition. The fact that these two fractions were active together but not separately strongly suggests that the active territorial signal results from a synergistic interaction between several compounds.

In the region of First near Grindelwald in the Swiss Alps, experiments were carried out on the reaction of alpine marmots Marmota marmota when confronted with hikers. Marmots in highly frequented areas showed less reaction to hiking activities than marmots in remote areas. In adult marmots, there was no change in reaction during the season. In young animals the reaction shortly after leaving the burrows in early July, was slight and similar in highly frequented and remote areas. In late summer, the intensity of the reaction of young animals increased significantly in animals in both study groups but to a much larger extent in the remote areas. We conclude that the perception of danger has to be learned or is built up during growth and development. At the same time, young animals in highly frequented areas may adjust to the presence of hikers.

International audience; The effects of several environmental factors on the postweaning growth of wild Alpine marmots were investigated. Factors considered were year of birth, sun exposure in the home range, litter size, and sex of young, Components of growth were juvenile mass at emergence from the natal burrow (as a result of preweaning growth) and postweaning growth rate. We also considered the length of the active season during which growth occurs. Mass at emergence and postweaning growth rate varied according to year of birth, were higher in south-facing than in north-facing home ranges, and were higher in small litters. Mass at emergence was higher for males than for females. We suggest that environmental factors affected the juvenile growth pattern through influences on maternal body condition. Our results support Trombulak's hypothesis that mothers maintain as many young as physiologically possible. We suggest that mothers in poor condition sacrificed the mass of their offspring rather than their number. A body mass sexual dimorphism of juveniles occurred at emergence, suggesting that mothers may provide more care for their male than their female offspring.

The way that plants and animals respond to climate change varies widely among species, but the biological features underlying their actual response remains largely unknown. Here, from a 20-year monitoring study, we document a continuous decrease in litter size of the Alpine marmot (Marmota marmota) since 1990. To cope with harsh winters, Alpine marmots hibernate in burrows and their reproductive output should depend more on spring conditions compared to animals that are active year-round. However, we show that litter size decreased over time because of the general thinning of winter snow cover that has been repeatedly reported to occur in the Alps over the same period, despite a positive effect of an earlier snowmelt in spring. Our results contrast markedly with a recent study on North American yellow-bellied marmots, suggesting that between-species differences in life histories can lead to opposite responses to climate change, even between closely related species. Our case study therefore demonstrates the idiosyncratic nature of the response to climate change and emphasizes, even for related species with similar ecological niches, that it may be hazardous to extrapolate life history responses to climate change from one species to another.

Woodchucks ( Marmota monax ) are a solitary species that, unlike other species of marmots, hibernate singly. The object of this study was to analyze how this species copes with harsh winter conditions in the field, in the northern part of its range. Woodchucks in the population studied have a pattern of hibernation similar to that of alpine marmots ( Marmota marmota ), they face comparable burrow temperatures, and their range of body temperatures is similar. However, woodchucks lose more weight than alpine marmots, both on a daily basis and throughout the period of hibernation. Woodchucks are less specialized than montane species of marmots, but their hibernacula provide better insulation than those employed by species residing in mountainous habitats.

The aim of this fieldwork was to provide information about the function of scent-marking behaviour in the alpine marmot (Marmota marmota). Twenty-three identified animals were observed on their home range during the season of activity, from May to September, during which the probability and rate of cheek rubbing decreased significantly. Cheek rubbing was performed more by resident adults than by 2-year-olds or yearlings. The resident adult pairs made "marking tours" during which numerous successive bouts of scent marking occurred throughout most of the home range. Scent marks were not evenly distributed within home ranges. Principal and, if present, accessory burrow systems were saturated with scent deposits, the boundaries being marked significantly more than the central area. We tested the reactions of marmots to strange odours by presenting them with two glass tubes, one clean (control) and the other covered with marks deposited by marmots belonging to other groups. The results showed that residents tended to mark the experimental tubes more frequently, or at least more intensively, than the control ones. In the alpine marmot, cheek rubbing appears to be a multipurpose activity. It is used to advertise the occupancy of burrows and, as predicted by Gosling, scent marks were also laid down where the risk of intrusion was greatest, i.e., at the boundaries, so that intruders could detect them more readily. The results of field tests support another of Gosling's predictions, that residents will tend to overmark any mark deposited by a strange animal inside their territory. Thus, in the alpine marmot, cheek rubbing can play a role in territorial defence.

The present distribution of the Alpine marmot Marmota m. marmota (Linnaeus, 1758) in Austria, the historical range during the Pleistocene, and recent efforts of re-introduction were documented. Autochthonous populations inhabit a continuous range extending over the western part of the Austrian Alps. Non-autochthonous populations occur in a more fragmented area of partly isolated massifs in the east. The non-autochthonous populations were generated by the release of only a few founder individuals (median = 5). The impact of founder effects and migration barriers on the structure of the disjunct non-autochthonous populations is confirmed by the genetic analysis of allozymes and VNTR-loci. Whereas autochthonous populations are characterized by high genetic similarity and common polymorphisms, the non-autochthonous populations exhibit a more patchy pattern of variation caused by founder effects and subsequent drift. From the relationships indicated by the VNTR-patterns it appears possible to infer the putative origin of the founder individuals. In previous allozyme studies the genetic variability was found to be reduced with the exception of two widespread polymorphisms at the loci Pep-1 and Sod-1. A parasitological survey shows that Pep-1 genotypes differ in their degree of infestation by endoparasites (Citellina alpina and Ctenotaenia marmotae) indicating that this polymorphism may be maintained by selective forces.

Hibernation in most mammals is accompanied by a pronounced seasonal body weight cycle. Fat is accumulated during summer and consumed during the following hibernation season. We investigated the annual time course of energy intake and energy expenditure and their interrelation with seasonal body weight fluctuations and hibernation in captive alpine marmots (Marmota marmota). All animals exhibited an annual body weight cycle with maximum weights in October and minimum weights after termination of hibernation, regardless of food availability during the hibernation season. Both energy uptake and expenditure reached highest values between June and August, when highest rates of body weight gain were observed. Between May and August energy intake exceeded the expenditure by an average of 383 ± 28.3 kJ/d. From September onward, when weight gain in marmots was reduced, the energy balance became less positive. During the normal hibernation season a negative energy balance was observed, even when food was available....

Sex-specific senescence has been commonly reported in highly dimorphic and polygynous species. However, whether between-sex differences in senescence occur in monogamous and monomorphic species is poorly known. In this study, we used an extensive dataset of 20 years of mass measurements on free-ranging male and female Alpine marmots (Marmota marmota), a medium-sized, long-lived, social and hibernating mammal, to assess sex-specific patterns of senescence in body mass. We tested for the occurrence of both a decrease in body mass scaled to absolute age (called chronological senescence) and a decrease in body mass scaled to individual age at death (called terminal decline). Whereas males showed evidence of both chronological senescence and terminal decline in body mass, females did not show any detectable senescence in body mass. This unexpected between-sex difference of senescence in a species subject to weak sexual selection might be shaped either by costs of an asymmetric intra-sex competition for mates or by costs of social thermoregulation.

Prostaglandins (PG) are involved in thermoregulation and reproduction. We investigated seasonal variation of PG in brain regions of two hibernators, the Alpine marmot (Marmota marmota) and the yellow-bellied marmot (Marmota flaviventris). The cerebrum, cerebellum, and basal forebrain homogenates of 24 animals were assayed for PGD2 by competitive enzyme immunoassay, and of 18 M. marmota also for PGE2 by radioimmunoassay. PGD2 concentration was always higher than that of PGE2. PGD2 was already high at emergence from hibernation, rapidly increased during the following 2 weeks when marmots mate, and declined thereafter to late summer nadir. During winter, PGD2 concentrations apparently increased, and, in contrast, PGE2 concentrations seemed to be lower. These observations support the putative role of PGD2 in lowering body temperature (T b) during hibernation and of PGE2 in elevating T b during the summer-active season. This suggests that, with the exception of the spring mating season, a reciprocal production of PGD2 and PGE2 in brain regions of hibernators during different seasons. Results indicate further that the availability of polyunsaturated fatty acids (PUFA) of the n-6 series is important for PGD2 synthesis and reproduction. During winter and spring, when fat is the major metabolic fuel, adult Alpine marmots metabolized less n-6 PUFA compared to other fatty acids; in contrast to younger, still immature individuals. Thus, high availability of n-6 PUFA may not only lower energy expenditure during hibernation, but also improve reproductive success in the subsequent year.

Habitat preferences of alpine marmots, Marmota marmota, were investigated at two sites in the French Alps. The use of a logistic-linear model allowed us to model the probability of marmot settlement in different ecological situations. Marmots preferred sites with a southern or eastern aspect (where snow melts relatively early), intermediate slopes, moderate plant cover, and a low level of human disturbance, and they seemed to select their habitat according to a nested system. To test if habitat quality affected individual fitness, we investigated the effects of sun exposure and two home-range characteristics on litter size at emergence, frequency of female reproduction, and retention of subordinates. Sun exposure and home-range size are two major components of home-range quality that may affect individual fitness.

Genetic heterogeneity is usually considered an important factor for the viability of a population, yet there are cases in which populations sustain themselves despite virtual homozygosity. A prior step to studying the effects of such low levels of genetic variability can be the analysis of its causes. We analysed a population of the highly social alpine marmot (Marmota marmota, Sciuridae) by multilocus DNA fingerprinting. The fingerprint patterns revealed a very low degree of polymorphism in our main study population. We show that this lack of hypervariability is caused by a low effective population size, rather than by an unusual low mutation rate of the fingerprint loci studied. However, the current number of breeding pairs was found to be about an order of magnitude larger than the one that would be expected to lead to such a low degree of heterozygosity. We conclude that there must have been bottlenecks in the history of the Berchtesgaden marmot population that have severely affected its genetic heterozygosity.

The composition and social interactions of three family groups of Marmota marmota were observed during a study in the Vanoise National Park (French Alps) from mid-June to late September. Interactions between members of the same group were mainly cohesive, which confirms the social nature of this species. Social interactions between marmots from different family groups were rare and agonistic. The rate of social interactions decreased as the season progressed, probably in relation to a shift in allocation of energy to preparation for hibernation. Some cohesive interactions increased just before immergence, when marmots restricted their activity to the main burrow system. Rates of social interactions differed between groups and between individuals. Fewer agonistic acts, more play-fighting, and persistence of play-fighting late in the active season among immatures suggest the influence of an ontogenetic component. The most agonistic of the studied groups included an adult male that had recently immigrated. He focused most of his agonistic acts on three 2-year-old males, of which two dispersed during the season. Social events characteristic of each group, individual variability, and level of familiarity between group members influence the quality of social interactions and the dispersal of immatures. Social relationships between familiar individuals are amicable and can facilitate the retention of immatures in their natal group as well as their recruitment by emigrant adults.

Preleuthner M. and Pinsker W. 1993. Depauperated gene pools in Marmota m. marmota are caused by an ancient bottle neck: electrophoretic analysis of wild populations from Austria and Switzerland. [In: Ecological genetics in mammals. G. B. Hartl and J. Markowski, eds]. Acta theriol. 38, Suppl. 2: 121 - 139. Samples from 15 populations of the Alpine marmot Marmota m. marmota (Linnaeus, 1758) were surveyed electrophoretically for allozyme variation. Only 2 out of 50 enzyme loci showed polymorphism. Average heterozygosity was found to be low with 1.2%. No rare alleles were detected among the 8430 genes examined. The geographic variation at the two polymorphic loci (Pep-1 and Sod-1) was analysed in more detail. The distribution pattern of the allele frequencies indicates genetic differentiation between autochthonous and introduced populations. No striking deviations of the genotype distributions from Hardy-Weinberg equilibrium were observed. Thus the population structure is apparently not affected by inbreeding. The obviously diminished genetic variation and the geographic pattern of the allele frequencies at the two variable loci can be best explained by assuming a severe bottleneck in the recent past.

In the region of First near Grindelwald (Swiss alps) alpine marmots Marmota marmota reacted differently to various forms of hiking tourism. The smallest reaction was recorded when hikers kept to trails. The reaction increased with cross-country hiking and was even greater when the main burrows of the animals were crossed. The severest reaction was seen in experiments with dogs on a long leash. It can be concluded that the predictability and potential threat (dogs) are decisive factors in the reactions of marmots to different forms of hiking.

Muscle samples from 7,142 wild boars (Sus scrofa), 80 free-ranging hogs, 1,462 red foxes (Vulpes vulpes) 90 mustelids, 15 Alpine marmots (Marmota marmota), 873 rodents and 92 insectivores were examined for Trichinella Railliet, 1895. A wild boar, a badger (Meles meles) and 30 foxes (2.1%) were found to be infected. Eleven vulpine isolates and the wild boar isolate were identified as Trichinella britovi. These results show that the wild boar has little significance as a reservoir of T. britovi in the area under study. A vulpine isolate resulted in low infectivity in experimentally-infected swine. The prevalence of trichinellosis in the vulpine population is higher in the mountains than in lowland areas and indicates the key role played by this carnivore in the epidemiology of T. britovi. Preliminary results from four field trials seem to demonstrate that differences in attitudes towards cannibalism exist between mountain and lowland foxes.