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1. 1. In the anesthetized marmot (Marmota marmota) the role played by the arterial chemoreceptors during FI02 changes has been demonstrated by the parallel time courses followed by the simultaneously recorded ventilatory and carotid sinus nerve responses. 2. 2. The effect of hypercapnia (even potentiated by a simultaneous hypoxia) was small compared to that in non-hibernators, although the arterial chemoreceptors most likely play a role in this reaction.

The social behaviour of a colony of yellow-bellied marmots was studied from June 18th to August 30th, 1955; July 12th to August 24th, 1956; June 10th to August 23rd, 1957; and June 14th to August 21st, 1961. The colony is located along a river terrace near the south entrance of Yellowstone National Park on the east side of the Snake River slightly south of the junction of the Lewis and Snake Rivers. The home-burrow is where the young are reared, where an animal normally spends the night, and where an animal goes when an alarm call is given. Auxiliary burrows are used temporarily as a place of refuge. The burrows are connected by a trail system that directs the movements of the animals. The distribution of adults and litters indicated a preference for burrows in the central part of the colony. Patterns of home range were of three types, those with no overlap, those with slight overlap and those with major overlap. Animals which utilized the same home range frequently avoided one another. The shape of the home range depended primarily on the nearness of the feeding area. Agonistic behaviour modified both size and shape of home ranges. Some home ranges were larger when the population was more dense or when agonistic behaviour was more frequent. Patterns of home range tended to change during the first two weeks of August when some animals hibernated. Changes in home range from year to year were correlated with changes in the individuals occupying home-burrows. The animals emerged from their burrows at about sunrise. There was a morning peak of activity followed by a midday low with a subsequent second peak of activity in the late afternoon. All the animals entered their burrows by 30 minutes after sunset. Communication between marmots involved the senses of sight, smell, touch, and, most importantly, hearing. The alarm call was given in response to any kind of intrusion into the life of the colony. No particular animal acted as a sentinel. Olfactory communication consisted of the “greeting” in which two animals sniffed each other's cheeks. One or two animals were dominant. Several tended to be submissive to all with which they had contact. Females with young may be aggressive in the vicinity of their home-burrows toward other animals, but may be submissive in other parts of the colony. Other relationships seem best characterized by a kind of neutrality in which each of the two animals avoids the other. Dominance is characterized by independence of action, tail flagging and grooming. Submissiveness is characterized by avoidance of other animals, slinking posture with tail down and submission to being groomed. Territorial behaviour does not seem to occur in the yellow-bellied marmot. Hibernation began in the second week of August. Conflicts and alert calls were less numerous and activity in general greatly decreased. Increased wandering was shown by some adults. It is postulated that agonistic behaviour is one of the factors that limits the number of marmots on a colony site.

Unter den gleichen Gesichtspunkten wie bei den Siebenschlafern (Glis glis L.) wurden die Lipoide des Alpenmurmeltieres (Marmota marmota) analysiert. Auch bei diesen treten gelbe Lipochrome und braune Verfarbungen bestimmter Gewebsteile auf. Der Vitamin E-Gehalt entspricht dem anderer tierischer Fette, erscheint aber im Hinblick auf den stark ungesattigten Charakter der Gesamtlipoide gering. Verallgemeinerungen in bezug auf die Deutung der Zusammenhange zwischen Schlaf und Lipoid-Beschaffenheit sind vorerst nicht moglich. Pro- and Antioxidants in the Field of Fats XIX: Fats and Fat-Metabolism of Hibernating Animals II. The Composition of the Fats from Alpsmarmot (Marmota marmota L.) With the same viewpoint as for the seven sleepers (Glis glis L.), the lipids of the alpsmarmot (Marmota marmota) were analysed. In case of these also the yellow lipochrome and brown coloration of certain tissue parts occur. The vitamin E content is in accord with other animal fats but appears to be small compared to the strongly unsaturated character of the total lipids. Generalization with regard to the interpretation on the relation between sleep and lipid composition is at present not possible.

This report presents the results of a 3-year study of the Olympic marmot in Olympic National Park. The animals inhabited sub-alpine and alpine meadows and formed closelyorganized colonies with extensive burrow systems. Southern exposures were preferred and no correlation of seasonal emergence with snow depth was apparent. Marmots ate nearly all meadow plants plus occasional animal matter early in the season. A variety of natural predators were present, and instances of predation by a cougar and coyote are reported. Visual and accoustic communication is described and sonograms of different vocalizations are presented. Activity patterns paralleled those reported for other marmot species, with early-morning and late afternoon peaks. Detailed activity budgets are presented, indicating behavioural differences among sex and age classes, and with changes in season. Records of weights are presented for all classes, indicating steady seasonal increases and sharp declines during hibernation. A black moult began in mid-summer and is apparently unique to the Olympic marmot. Most colonies were composed of one adult male, two adult females, a litter of yearlings and a litter of infants. Occasionally one or more 2-year-olds and one or two ‘satellite’ adult males were present. Colony members generally hibernated together but parous females and satellite males moved away to separate burrows shortly after emergence. Varying combinations of living arrangements are described. Greeting behaviour was analysed and quantified as a major component of marmot sociality. Greeting frequency varied significantly with age and sex class, season and time of day: it was especially high in the morning, among adult males in the spring, and among infants. Dominance relations were generally diffuse, except those between resident and satellite males (resident dominated) and between pregnant or lactating females and any other animal (female dominated). Individual territories and home ranges did not exist within colonies. Quantification of inter-individual distances revealed a tendency for greater aggregation early in the season among most animals but greater earlyseason repulsion between resident and satellite males. The ontogeny of infant activity is quantitatively described, demonstrating progressively more time spent above ground and increased distance travelled from the home burrow. The decline in association between females and their litters is also described. Upright, ‘play-fighting’ was common and showed age, sex and seasonal differences with high levels among adult males early in the season and among infants. ‘Playfulness’ was prominent in marmot social behaviour. Burrow visiting, greeting, social grouping and playfighting all reflected intense social interaction early in the season with gradual declines later. Flow charts of sexual activity are used to compare the behaviour patterns of parous and nonparous females and to analyse changes in pattern with time following emergence. Distinct oestrus behaviour was apparent for the parous females, peaking during the second week post-emergence. Interactions between colonies are also described: they generally evidenced lower frequencies and greater intensities of agonism than did withincolony behaviours. The social system of M. olympus was shown to be more closely integrated and less aggresively-organized than that of the yellow-bellied marmot, M. flaviventris, which in turn is more highly social than the woodchuck, M. monax. Survivorship data indicate that mortality rates were highest among infants and during the winter, especially during winters with scanty snowfall. Two-year-olds dispersed upon seasonal emergence in colonies where winter mortality was low; however, following high winter mortality and consequent small colony size at emergence, dispersal did not occur. Thus, colony population size was maintained essentially constant and relatively independent of yearly fluctuations in mortality or recruitment. Dispersal from large colonies was correlated with behavioural responses of the 2-year-olds to a relatively high level of social interaction in these colonies. Olympic marmot females mature at 3 years and bear young in alternate years only. The evolutionary significance of biennial breeding is considered, and this population system is interpreted as providing maximum effective reproduction under the conditions of extremely short growing season prevailing in the marmot meadows. Comparison with other North American marmots reveals a progressive decrease in length of growing season experienced by the wood-chuck, yellow-bellied and Olympic marmots. This in turn correlates with decreases in proportional growth rates and breeding frequency, and increases in age at dispersal, age at sexual maturity and in the degree of ‘sociality’ of these marmot species. Implications for the evolution of marmot behaviour are discussed, including the suggestion that exposure to progressively shortened growing seasons favours the development of less aggressively-organized social systems.

Ventilation has been measured in hibernating marmots, Marmota marmota, with a total body plethysmograph. Breaths were separated by variable periods ofapnea; the respiratory period ranged from O.5 to 6 min (mean 1.2 min). Mean ventilatory flow rate was 30.3 ± 7.0 ml btps · m −1 . An early sign of arousal was a great increase of ventilatory flow rate, before any significant increase in oxygen consumption and body temperature. Measurement of pH and PCO2 of arterial blood samples via indwelling catheters gave the following values: euthermic hamster Cricetus cricetus (body temperature 37–38°C): pH = 7.40, PCO2 = 45.3 torr, [HCO3−] = 28.2 meq·L−1; hibernating hamster (body temperature 9°C): pH = 7.57, PCO2 = 36.1 torr, [HCO3−] = 53.8 meq·L−1; hibernating marmot (body temperature 8°C): pH = 7.57, PCO2 = 33.3 torr, [HCO3−] = 52.8 meq·L−1. These data confirm the existence of a new, stable acid-base state in hibernating mammals, with a pH 0.17 unit higher than in euthermic conditions. In contrast, in poikilotherms, for the same decrease of body temperature blood pH would increase by about O.50 unit, i.e. by the same amount as the pH of neutrality of water, relative alkalinity remaining thus constant. Hibernating mammals may thus be viewed as relatively acidotic. The significance of these findings is discussed.

Adult nematodes of the genus Ascaris Linn., 1758 are seldomn found in rodents. Four species are listed by Hall (1916): A. castoris Rudolphi, 1809, from Castor fiber; A. laevis Leidy, 1856 from Marmota (Arctomys) monax; A. pigmentata von Linstow, 1897, from Marmota marmota; Ascaris sp., reported by Parona in 1909, from Mus minutoides. Ascaris castoris and Ascaris sp. were inadequately described and A. laevis was recently redescribed by Tiner (1951) from specimens obtained from Pennsylvanian and Alaskan woodchucks. Tiner also considered worms identified as A. columnaris Leidy, 1856 by Linsdale to be "a variant of A. laevis." Because of certain morphological characteristics possessed by A. pigmentata which resemble those of the subfamily Anisakinae Railliet and Henry, 1912, Hall felt that this species belonged in another genus. He further suggested that perhaps Ascaris sp. and A. castoris were erroneously placed. Ascaris joffi, from Citellus pygmaerus and A. tarbagan, from Marmota sibirica were described by Schultz (1931). Ascaris lumbricoides, genotype, is primarily a parasite of humans and pigs; however, there have been several reports of the accidental occurrence of the species in sciurids (Sciurus niger, by Rausch and Tiner, 1948 and by Thomas (cited by Brown and Yeager, 1945); S. indicus listed by Baylis, 1939) and murids (Ondatra zibethica by Tiner and Chin, 1948). Specimens of A. laevis were collected from several ground squirrels, Citellus undulatus, on St. Lawrence Island, Alaska by Dr. L. J. Thomas and the writer. The range of infection was 2 to 4 worms per animal. Because of the infrequent occurrence of members of the genus in rodents and the lack of adequate information relative to the life history of such forms, experimental studies with the species were undertaken. Pathology in experimentally infected hosts due to A. laevis was reported by the writer (1959) and a paper on the "trachealmigration" of the species is in press. The present study on larval morphology is primarily based upon material observed in and recovered from experimentally infected hosts (Citellus tridecemlineatus, C. franklini, and Marmota monax).