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 Distinction between distribution of masses of Wolf-Rayet stars and that of relativistic objects

2003 ◽  
Vol 212 ◽  
pp. 372-376
Author(s):  
Anatol M. Cherepashchuk
Keyword(s):  
Magnetic Field ◽  
Black Holes ◽  
Mass Loss ◽  
Loss Rate ◽  
Mass Loss Rate ◽  
Continuous Distribution ◽  
Core Mass ◽  
The Masses ◽  
Dependent Mass ◽  
Mass Dependent

The final masses MCO,f for the CO-cores of WR stars with known masses are calculated taking into account mass-dependent mass loss of WR stars and clumping structure of the WR wind which allows the mass loss rate to be decreased by a factor of 3. The masses of MCO,f lie in the range (1-2) - (20-44)M⊙ and have continuous distribution in contrast with distribution of masses Mx of relativistic objects. The distribution of Mx seems to be bimodal with a gap in the range Mx = 2-4 M⊙. A mean CO-core mass <MCO,f = 7.4-10.3 M⊙ is close to that of black holes: <MBH = 8-10 M⊙. Difference between distributions of MCO,f and Mx allows us to suggest that the nature of a formed relativistic object (neutron star, black hole) is determined not only by the mass of a progenitor but also by some other parameters: rotation, magnetic field, etc.

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.

scholarly journals A new specimen-dependent method of estimating felid body mass

2016 ◽  
Author(s):  
Shaheer Sherani
Keyword(s):  
Body Mass ◽  
The Body ◽  
Long Bone ◽  
Panthera Tigris ◽  
Living Species ◽  
Smilodon Fatalis ◽  
The Difference ◽  
The Masses ◽  
Bone Dimensions ◽  
Panthera Atrox

Background. The estimation of body mass of long extinct species of the family Felidae has been a focus of paleontology. However, most utilized methods impose expected proportions on the fossil specimens being estimated, resulting in a high chance of underestimation or overestimation. This study proposes a new method of estimating felid body mass by accounting for osteological proportionality differences between the extinct taxa being estimated and the living species being used as comparisons. Method. Using a manipulation of the cube law, 36 equations were formulated that estimate body mass based on certain humeral and femoral dimensions. The formulated equations were used to examine whether the mass of living comparison species, namely the tiger (Panthera tigris), the lion (Panthera leo), and the jaguar (Panthera onca), depends equally on a select set of long bone dimensions. The body mass of five extinct felids, namely Panthera atrox, Panthera spelaea, Panthera tigris soloensis, Smilodon populator, and Smilodon fatalis, was also estimated. Results. Living comparisons species were found to somewhat incorrectly estimate other living comparison species. All five extinct taxa were found to weigh well over 300 kg, with the largest of the species weighing nearly 500 kg. Discussion. The inability of one living comparison species to predict the mass of another with strong accuracy suggests that bone dimensions do not solely influence body mass. Discrepancies between the masses of Smilodon populator and Smilodon fatalis were likely the product of the difference in available niches in late Pleistocene North and South America. The masses of Panthera spelaea and Panthera atrox indicate a discrepancy in sociality between the two closely related species. Lastly, the extreme body mass of Panthera tigris soloensis points to great plasticity within the tiger lineage in terms of size, indicating that such variations among tiger populations may not warrant subspeciation.

Occurrence of Eimeria tamiasciuri in Ontario red squirrels (Tamiasciurus hudsonicus)

1969 ◽  
Vol 47 (4) ◽  
pp. 731-732 ◽  
Author(s):  
Bee-Ling Soon ◽  
R. S. Dorney
Keyword(s):  
Tamiasciurus Hudsonicus ◽  
Red Squirrels ◽  
Central Canada ◽  
First Time

E. tamiasciuri is reported for the first time from Ontario (92.3% of 13 red squirrels). It resembles closely in size oocysts described from Wisconsin but is considerably smaller than those from Arizona. This extends the range of this parasite into central Canada.

scholarly journals A new specimen-dependent method of estimating felid body mass

2016 ◽  
Author(s):  
Shaheer Sherani
Keyword(s):  
Body Mass ◽  
The Body ◽  
Long Bone ◽  
Panthera Tigris ◽  
Living Species ◽  
Smilodon Fatalis ◽  
The Difference ◽  
The Masses ◽  
Bone Dimensions ◽  
Panthera Atrox

Background. The estimation of body mass of long extinct species of the family Felidae has been a focus of paleontology. However, most utilized methods impose expected proportions on the fossil specimens being estimated, resulting in a high chance of underestimation or overestimation. This study proposes a new method of estimating felid body mass by accounting for osteological proportionality differences between the extinct taxa being estimated and the living species being used as comparisons. Method. Using a manipulation of the cube law, 36 equations were formulated that estimate body mass based on certain humeral and femoral dimensions. The formulated equations were used to examine whether the mass of living comparison species, namely the tiger (Panthera tigris), the lion (Panthera leo), and the jaguar (Panthera onca), depends equally on a select set of long bone dimensions. The body mass of five extinct felids, namely Panthera atrox, Panthera spelaea, Panthera tigris soloensis, Smilodon populator, and Smilodon fatalis, was also estimated. Results. Living comparisons species were found to somewhat incorrectly estimate other living comparison species. All five extinct taxa were found to weigh well over 300 kg, with the largest of the species weighing nearly 500 kg. Discussion. The inability of one living comparison species to predict the mass of another with strong accuracy suggests that bone dimensions do not solely influence body mass. Discrepancies between the masses of Smilodon populator and Smilodon fatalis were likely the product of the difference in available niches in late Pleistocene North and South America. The masses of Panthera spelaea and Panthera atrox indicate a discrepancy in sociality between the two closely related species. Lastly, the extreme body mass of Panthera tigris soloensis points to great plasticity within the tiger lineage in terms of size, indicating that such variations among tiger populations may not warrant subspeciation.

Body mass and first-time reproduction in female chipmunks (Tamias striatus)

1997 ◽  
Vol 75 (11) ◽  
pp. 1891-1895 ◽  
Author(s):  
G. E. Svendsen ◽  
M. M. White
Keyword(s):  
Body Mass ◽  
Food Availability ◽  
Season Of Birth ◽  
Tamias Striatus ◽  
Time Reproduction ◽  
Eastern Chipmunk ◽  
First Reproduction ◽  
First Time ◽  
The Relationship

Body mass has been proposed as a factor that contributes to the onset of puberty in some species of mammals. In this study we examined the relationship between body mass and primiparity in the eastern chipmunk (Tamias striatus) by comparing females that reproduced and those that did not during any given breeding opportunity. We also investigated whether season of birth influenced the season of first reproduction. No differences in season of first reproduction were observed between spring-born and fall-born females. Females that produced a litter had significantly greater body mass than did females that did not. Significant differences in body mass were also observed, based on season of birth. Food availability and timing of hibernation may be important contributors to the observed pattern.

scholarly journals A new specimen-dependent method of estimating felid body mass

2016 ◽  
Author(s):  
Shaheer Sherani
Keyword(s):  
Body Mass ◽  
The Body ◽  
Long Bone ◽  
Panthera Tigris ◽  
Living Species ◽  
Smilodon Fatalis ◽  
The Difference ◽  
The Masses ◽  
Bone Dimensions ◽  
Panthera Atrox

Background. The estimation of body mass of long extinct species of the family Felidae has been a focus of paleontology. However, most utilized methods impose expected proportions on the fossil specimens being estimated, resulting in a high chance of underestimation or overestimation. This study proposes a new method of estimating felid body mass by accounting for osteological proportionality differences between the extinct taxa being estimated and the living species being used as comparisons. Method. Using a manipulation of the cube law, 36 equations were formulated that estimate body mass based on certain humeral and femoral dimensions. The formulated equations were used to examine whether the mass of living comparison species, namely the tiger (Panthera tigris), the lion (Panthera leo), and the jaguar (Panthera onca), depends equally on a select set of long bone dimensions. The body mass of five extinct felids, namely Panthera atrox, Panthera spelaea, Panthera tigris soloensis, Smilodon populator, and Smilodon fatalis, was also estimated. Results. Living comparisons species were found to somewhat incorrectly estimate other living comparison species. All five extinct taxa were found to weigh well over 300 kg, with the largest of the species weighing nearly 500 kg. Discussion. The inability of one living comparison species to predict the mass of another with strong accuracy suggests that bone dimensions do not solely influence body mass. Discrepancies between the masses of Smilodon populator and Smilodon fatalis were likely the product of the difference in available niches in late Pleistocene North and South America. The masses of Panthera spelaea and Panthera atrox indicate a discrepancy in sociality between the two closely related species. Lastly, the extreme body mass of Panthera tigris soloensis points to great plasticity within the tiger lineage in terms of size, indicating that such variations among tiger populations may not warrant subspeciation.

scholarly journals Size Matters: Zoo Data Analysis Shows that the White Blood Cell Ratio Differs between Large and Small Felids

Animals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 940
Author(s):  
Sergey V. Naidenko ◽  
Mikhail V. Alshinetskiy
Keyword(s):  
Body Mass ◽  
Blood Cells ◽  
Prey Size ◽  
White Blood Cells ◽  
Home Range Size ◽  
The Body ◽  
Warm Blood ◽  
Utilization Time ◽  
Regular Contact ◽  
First Time

The total number of white blood cells (WBCs) is related the immune system. In mammals, it is affected by the body mass, but it is unclear how the numbers of different WBC types correlate with this parameter. We analyzed the effect of body mass on WBC number and ratio in felids, where species are similar in diet (warm-blood vertebrates) and reproductive strategy (promiscuity). Based on zoo veterinary data (ZIMS database) we analyzed the effect of body mass on WBC number and neutrophils/lymphocytes ratio in 26 species of felids. The number of WBCs correlated with the body masses of animals: large cats had more WBC, which may be due to greater risks of infection associated with larger body surface, lifespan and home range size. For the first time we found obvious differences in the number of WBC types. Large cats also had more neutrophils and monocytes but fewer lymphocytes than smaller cats. The ratio of neutrophils to lymphocytes is greater in large felids. This phenomenon may be related to diet (relative prey size and kill utilization time), which suggests regular contact of large cats with bacterial and protozoal pathogens in contrast to the small cats.

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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