Maternal influence on juvenile growth rates in Belding's ground squirrel (Spermophilus beldingi)

1991 ◽  
Vol 69 (8) ◽  
pp. 2140-2145 ◽  
Author(s):  
Stephen C. Trombulak
Keyword(s):  
Body Mass ◽  
Sierra Nevada ◽  
Early Summer ◽  
Ground Squirrels ◽  
The Body ◽  
Supplemental Food ◽  
Sierra Nevada Mountains ◽  
Extra Food ◽  
Spermophilus Beldingi ◽  
Reproductive Females

The influence of food acquisition by pregnant and lactating Belding's ground squirrels (Spermophilus beldingi) on the body mass and growth rate of their offspring was assessed in a free-ranging population. In late spring and early summer of 1985 and 1986, individual females in a population of Belding's ground squirrels in the Sierra Nevada Mountains of California were given 300–500 g of sunflower seeds daily at the entrances to their burrows. Juveniles born to mothers who received supplemental food emerged from natal burrows on average 28% heavier than did controls (73.0 vs. 57.1 g, P < 0.001) and maintained a greater body mass throughout the remainder of the summer (P < 0.01). Also, females had a nonsignificant tendency towards greater survivorship during their first winter (P = 0.09). Supplemental feeding had no effect on litter size or sex ratio of offspring, or on the mass of the mothers up to the time of weaning, indicating that extra food available in the spring to reproductive females is converted primarily, if not exclusively, into larger offspring. Because the lengths of gestation and lactation are relatively invariable, the greater body mass of emerging juveniles must result from faster growth prior to weaning.

Seasonal effects of food provisioning on body fat, insulin, and corticosterone in free-living juvenile Belding's ground squirrels (Spermophilus beldingi)

2002 ◽  
Vol 80 (2) ◽  
pp. 366-371 ◽  
Author(s):  
Scott Nunes ◽  
Eva-Maria Muecke ◽  
Kay E Holekamp
Keyword(s):  
Body Fat ◽  
Plasma Insulin ◽  
Plasma Concentrations ◽  
Plasma Corticosterone ◽  
Ground Squirrels ◽  
Seasonal Effects ◽  
Free Living ◽  
Active Season ◽  
Extra Food ◽  
Spermophilus Beldingi

We evaluated the relationship between body fat and the metabolic hormones insulin and corticosterone in free-living juvenile Belding's ground squirrels (Spermophilus beldingi). Some free-living juveniles were provisioned with extra food high in fat and calories, and unprovisioned juveniles were used as controls. Body fat (as a percentage of body mass) of squirrels was regularly evaluated using non-invasive methods. Blood samples were also regularly collected from juveniles and assayed for plasma concentrations of insulin and corticosterone. Provisioned juveniles were fatter than unprovisioned juveniles during most of the active season, but differences in body fat disappeared near the end of summer as juveniles began fattening for hibernation. Thus, our data indicate that although body fat may fluctuate with energy availability early in the active season, it is regulated at precise levels as squirrels prepare for winter. Plasma corticosterone concentrations did not differ between provisioned and unprovisioned juveniles. However, plasma insulin concentrations were greater in provisioned than in unprovisioned juveniles early in the summer. Differences in insulin concentrations disappeared later in the active season, just prior to the disappearance of differences in body fat. Moreover, plasma insulin concentrations were significantly correlated with subsequent changes in body fat. Thus, our data suggest a link between insulin and seasonal regulation of body fat in juvenile S. beldingi.

scholarly journals Control of plague vectors on diurnal rodents in the Sierra Nevada of California by use of insecticide bait-boxes

1960 ◽  
Vol 58 (3) ◽  
pp. 347-355 ◽  
Author(s):  
Allan M. Barnes ◽  
Leo Kartman
Keyword(s):  
Sierra Nevada ◽  
Host Species ◽  
Ground Squirrel ◽  
Ground Squirrels ◽  
Flea Species ◽  
Home Ranges ◽  
Sierra Nevada Mountains ◽  
Citellus Lateralis ◽  
Residual Control

Trials were conducted in the Sierra Nevada Mountains of California to test the effectiveness of 10% DDT dust in insecticide bait-box stations against the fleas of native diurnal rodents. The principle host species involved were the chipmunks Eutamias amoenus and E. speciosus, and the golden-mantled ground squirrel, Citellus lateralis. The important flea species were Monopsyllus eumolpi and M. ciliatus on chipmunks, and Diamanus montanus and Oropsylla idahoensis on ground squirrels. When baited daily for 12 days and furnished with 50 g. of 10% DDT dust, the bait-box stations reduced fleas strikingly within 24 hr., but very little residual control was obtained. A second application in which boxes were baited only twice weekly but for 28 days, also resulted in rapid knockdown and a residual control still effective 42 days after removal of the bait-boxes. The effect of the DDT was apparent at a distance of 400 ft. from the nearest bait-box due to the relatively extensive home ranges of the hosts. Although, in these trials, bait-box stations were spaced 100 ft. apart, 200 ft. spacing probably would be as effective with these hosts.

scholarly journals Decreases in body temperature and body mass constitute pre-hibernation remodelling in the Syrian golden hamster, a facultative mammalian hibernator

2016 ◽  
Vol 3 (4) ◽  
pp. 160002 ◽  
Author(s):  
Yuichi Chayama ◽  
Lisa Ando ◽  
Yutaka Tamura ◽  
Masayuki Miura ◽  
Yoshifumi Yamaguchi
Keyword(s):  
Body Temperature ◽  
Body Mass ◽  
Core Body Temperature ◽  
Adaptive Strategy ◽  
Ground Squirrels ◽  
The Body ◽  
Syrian Hamsters ◽  
Hibernation Period ◽  
Strict Regulation ◽  
Physiological Markers

Hibernation is an adaptive strategy for surviving during periods with little or no food availability, by profoundly reducing the metabolic rate and the core body temperature ( T b ). Obligate hibernators (e.g. bears, ground squirrels, etc.) hibernate every winter under the strict regulation of endogenous circannual rhythms, and they are assumed to undergo adaptive remodelling in autumn, the pre-hibernation period, prior to hibernation. However, little is known about the nature of pre-hibernation remodelling. Syrian hamsters ( Mesocricetus auratus ) are facultative hibernators that can hibernate irrespective of seasons when exposed to prolonged short photoperiod and cold ambient temperature (SD-Cold) conditions. Their T b set point reduced by the first deep torpor (DT) and then increased gradually after repeated cycles of DT and periodic arousal (PA), and finally recovered to the level observed before the prolonged SD-Cold in the post-hibernation period. We also found that, before the initiation of hibernation, the body mass of animals decreased below a threshold, indicating that hibernation in this species depends on body condition. These observations suggest that Syrian hamsters undergo pre-hibernation remodelling and that T b and body mass can be useful physiological markers to monitor the remodelling process during the pre-hibernation period.

Effects of a spring snowstorm on behavior, reproduction, and survival of Belding's ground squirrels

1978 ◽  
Vol 56 (12) ◽  
pp. 2578-2590 ◽  
Author(s):  
Martin L. Morton ◽  
Paul W. Sherman
Keyword(s):  
Body Size ◽  
Sierra Nevada ◽  
Ground Squirrels ◽  
The Other ◽  
High Altitudes ◽  
Adult Females ◽  
Early Emergence ◽  
Other Hand ◽  
Body Weights ◽  
Spermophilus Beldingi

From 30 April to 26 May 1977 a snowstorm occurred in the Sierra Nevada where we were studying Spermophilus beldingi. The storm began 8 days after ground squirrels began emerging from hibernation. During the storm, emergence nearly ceased and mating was suspended, body weights decreased sharply, locomotor abilities became impaired, and nocturnal burrow sharing increased. The animals became more susceptible to predation, and one case of intraspecific killing and cannibalism was observed. At least four animals starved; they were totally depleted of fat and had atrophied livers. During the storm, more adult females than males perished; 60% of females disappeared in 1977 vs. 32 and 26% in 1975 and 1976, respectively. Furthermore, when compared with 1975 and 1976, fewer 1977 females mated, conceived, or weaned young.During 1969–1977 at Tioga Pass, first emergence of S. beldingi varied up to 6 weeks with the animals emerging earliest in years of lightest snowpacks. At high altitudes where summers are brief, early emergence may increase the likelihood that young will reach appropriate body size before winter. On the other hand, avoidance of the effects of unpredictable spring storms favors later emergence. In 1977, because of the snowstorm, late emergers were favored.

Mass-dependent reproduction or reproduction-dependent mass? A comment on body mass and first-time reproduction in female sciurids

1999 ◽  
Vol 77 (1) ◽  
pp. 171-173 ◽  
Author(s):  
Murray M Humphries ◽  
Stan Boutin
Keyword(s):  
Body Mass ◽  
The Body ◽  
Tamiasciurus Hudsonicus ◽  
Red Squirrels ◽  
Time Reproduction ◽  
Reproductive Females ◽  
The Masses ◽  
Dependent Mass ◽  
Mass Dependent ◽  
First Time

We question the validity of Svendsen and White's conclusion that body mass affects the timing of primiparity in eastern chipmunks (Tamias striatus) (G.E. Svendsen and M.M. White. Can. J. Zool. 75: 1891-1895. 1997). Because the masses of reproductive and non-reproductive females were measured during the postpartum period only, the differences reported by Svendsen and White may be due to reproductive females gaining more mass than non-reproductive females between the premating and postpartum periods. We evaluated the plausibility of this alternative explanation by comparing the body mass of reproductive and non-reproductive female red squirrels (Tamiasciurus hudsonicus). Like Svendsen and White, we found that postpartum reproductive females were significantly heavier than non-reproductive females, but contrary to their interpretation, these differences did not exist during the premating period. We conclude that primiparity in female sciurids may not be mass-dependent, but rather that postpartum mass differences may occur because reproductive females augment their energy reserves to help sustain reproductive demands during late lactation.

scholarly journals Costs of Franklin’s ground squirrel (Poliocitellus franklinii) ectoparasitism reveal adaptive sex allocation

2018 ◽  
Vol 96 (6) ◽  
pp. 585-591 ◽  
Author(s):  
Ellen M. Pero ◽  
James F. Hare
Keyword(s):  
Body Mass ◽  
Sex Allocation ◽  
Indirect Costs ◽  
Ground Squirrels ◽  
Male Offspring ◽  
Social Species ◽  
Reproductive Females ◽  
Franklin's Ground Squirrel ◽  
Poliocitellus Franklinii ◽  
And Control

Parasite infestation may impose direct costs of blood, nutrient, and energy depletion, along with indirect costs of increased immune response upon hosts. We investigated how ectoparasitism influences body mass and reproduction in a free-living population of Franklin’s ground squirrels (Poliocitellus franklinii (Sabine, 1822)) located near Delta Marsh, Manitoba, Canada. We experimentally reduced ectoparasite burden by treating seven reproductive females with an insecticide following breeding and contrasted body mass and reproductive performance of those individuals to seven sham-treated control females. Insecticide-treated dams did not differ from sham-treated dams in body mass, litter size, or juvenile mass, and thus, dam growth and reproduction were not compromised by ectoparasite defense at the infestation levels experienced in this study. However, litter sex ratio differed significantly between insecticide-treated and control females, with a higher proportion of male offspring produced among females with reduced ectoparasite load. Our findings are thus consistent with the Trivers–Willard model for adaptive sex allocation, yet they provide novel comparative insight into how sociality may modulate the expression of adaptive sex allocation among small mammals given the differential payoff associated with the production of high-quality female versus male offspring in more social versus less social species.

The Breeding biology of Pseudocheirus peregrinus viverrinus on FLinders ISland, Bass Strait

1995 ◽  
Vol 22 (4) ◽  
pp. 521 ◽  
Author(s):  
S Munks
Keyword(s):  
Body Mass ◽  
Nutrient Status ◽  
Early Spring ◽  
Early Summer ◽  
The Body ◽  
Birth Season ◽  
Adult Body Mass ◽  
Adult Body ◽  
Pseudocheirus Peregrinus ◽  
The Mean

Reproduction in Pseudocheirus peregrinus viverrinus in coastal teatree woodland on Flinders Island was seasonal. The main birth season was from May to August. The mean duration of lactation was 29 weeks. The duration of lactation for multiparous females that bred twice in a year was significantly shorter than that of multiparous single breeders. In general the young left the pouch during early spring and were fully weaned by the early summer months. In contrast to populations of P. peregrinus inhabiting similar woodland in Victoria only a few multiparous females (6-9%) gave birth to a second litter in the springlsummer months on Flinders Island. The mean litter size (1.84) and annual fecundity of the population (1.91 offspring per female) were lower than those reported for three populations of Pseudocheirus peregrinus in Victoria. It is suggested that the low occurrence of spring/summer births and low fecundity of P. p. viverrinus on Flinders Island may be related to the age and nutrient status of their coastal teatree forest habitat. The body mass of P. p. viverrinus was higher than previously recorded for P. peregrinus. The adult body mass of females ranged from 948 to 1082 g. Adults showed seasonal variation in body mass with most females losing weight during the late spring and summer months coincident with late lactation. It is proposed that the larger body size of P. p. viverrinus on Flinders Island is a result of release from predation pressure and/or interspecific competition.

191: Does the Body Mass Index Affect the Outcome Following Reconstruction of Orthotopic Neobladder?

2007 ◽  
Vol 177 (4S) ◽  
pp. 64-64
Author(s):  
Murugesan Manoharan ◽  
Martha A. Reyes ◽  
Alan M. Nieder ◽  
Bruce R. Kava ◽  
MarkS Soloway
Keyword(s):  
Body Mass Index ◽  
Body Mass ◽  
The Body ◽  
Orthotopic Neobladder
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