Reproductive effort of male hooded seals (Cystophora cristata): estimates from mass loss

1996 ◽  
Vol 74 (8) ◽  
pp. 1521-1530 ◽  
Author(s):  
Kit M. Kovacs ◽  
Christian Lydersen ◽  
Mike Hammill ◽  
David M. Lavigne
Keyword(s):  
Body Composition ◽  
Mass Loss ◽  
Body Mass ◽  
Breeding Season ◽  
Tritiated Water ◽  
Dive Depth ◽  
Dive Duration ◽  
Day Range ◽  
Ice Surface ◽  
Cystophora Cristata

This study investigated mass loss, body composition, and behaviour patterns of male hooded seals during the reproductive season. During the 6 years of study (between 1989 and 1995), 139 records of male mass were obtained that involved 115 individuals. Body masses of males ranged from 147 to 434 kg. Mean mass at first capture was 312.5 ± 53.0 kg (N = 119). Year, date of sampling, and age all significantly influenced mass. Nineteen males were recaptured at least twice during a single season. Mean rate of mass loss among these individuals was 2.5 ± 1.1 kg/day (range 0.7–4.6 kg/day). Body composition early in the breeding season, measured using tritiated water (N = 6), produced mean estimates of 51.6 ± 1.6% water, 29.3 ± 2.4% fat, 16.9 ± 0.7% protein, and 1.9 ± 0.2% ash. Time–depth recorders attached to three males indicated that they spent 84.7 ± 15.4% of their time hauled out on the surface of the ice during the breeding season. Each of these males was on the ice for a few days; they then spent a few hours at sea before returning to the ice surface. Mean dive depth was only 14.1 ± 3.2 m (maximum 66 m) and mean dive duration was only 1.7 ± 0.3 min (maximum 28 min). Extrapolating mean daily rates of body mass loss to encompass a 2.5-week breeding season, males would lose an average of 44 kg, which represents 14% of their mean body mass. Compared with values for males of other phocid species this value is conservative. It appears that the short breeding season among hooded seals is energetically advantageous for both sexes.

Stroke frequencies of emperor penguins diving under sea ice

2002 ◽  
Vol 205 (24) ◽  
pp. 3769-3774 ◽  
Author(s):  
R. P. van Dam ◽  
P. J. Ponganis ◽  
K. V. Ponganis ◽  
D. H. Levenson ◽  
G. Marshall
Keyword(s):  
Sea Ice ◽  
Dive Depth ◽  
Dive Duration ◽  
Accelerometer Data ◽  
Underwater Video ◽  
Stroke Frequency ◽  
Video Footage ◽  
Ice Surface ◽  
Emperor Penguins ◽  
Aerobic Dive Limit

SUMMARYDuring diving, intermittent swim stroke patterns, ranging from burst/coast locomotion to prolonged gliding, represent potential energy conservation mechanisms that could extend the duration of aerobic metabolism and, hence,increase the aerobic dive limit (ADL, dive duration associated with onset of lactate accumulation). A 5.6 min ADL for emperor penguins had been previously determined with lactate measurements after dives of <50 m depth. In order to assess locomotory patterns during such dives, longitudinal acceleration was measured with an attached accelerometer in 44 dives of seven adult birds diving from an isolated dive hole in the sea ice of McMurdo Sound, Antarctica. Detection of wing strokes in processed accelerometer data was verified in selected birds with analysis of simultaneous Crittercam underwater video footage. Mean dive duration of birds equipped with the accelerometer and a time-depth recorder (TDR) was 5.7±2.2 min; 48% of these dives were greater than the measured 5.6 min ADL (ADLM). Highest stroke frequencies (0.92±0.31 Hz, N=981) occurred during the initial descent to 12 m depth. Swimming effort was reduced to a mean stroke frequency<0.70 Hz during other phases of the dive (while traveling below 12 m depth,during foraging ascents/descents to and from the sub-ice surface, and during final ascents to exit). The longest stroke interval (8.6 s) occurred during a feeding excursion to the undersurface of the ice. In dives>ADLM, mean stroke frequency during travel segments was significantly less than that in dives <ADLM(P<0.05). Mean stroke frequency of the entire dive correlated inversely (P<0.05) with diving duration (r=-0.67) and with mean dive depth (r=-0.43). Emperor penguins did not exhibit any significant (>10 s) periods of prolonged gliding during these shallow(<60 m) foraging dives. However, a stroke/glide pattern was evident with more than 50% of strokes associated with a stroke interval >1.6 s, and with lower stroke frequency associated with increased dive duration.

Utilization of stored energy reserves during fasting varies by age and season in Steller sea lions

2007 ◽  
Vol 85 (2) ◽  
pp. 190-200 ◽  
Author(s):  
L.D. Rea ◽  
D.A.S. Rosen ◽  
A.W. Trites
Keyword(s):  
Mass Loss ◽  
Body Mass ◽  
Breeding Season ◽  
Lower Percentage ◽  
Metabolic Adaptation ◽  
Body Lipid ◽  
Steller Sea Lions ◽  
Sea Lions ◽  
Nonbreeding Season ◽  
Total Body

Nine captive Steller sea lions ( Eumetopias jubatus (Schreber, 1776), 1.75–6 years of age) were fasted for 7–14 d to test the effect of short-term fasting on changes in body mass and body condition. Trials were repeated during both the summer breeding season and the nonbreeding season in seven animals to elucidate whether there was a seasonal component to the ability of Steller sea lions to adapt to limited food resources. Mean percent mass loss per day was higher during the breeding season in juveniles (1.8% ± 0.2%·d–1) than in subadults (1.2% ± 0.1%·d–1), but there were no significant age-related differences during the nonbreeding season (juveniles, 1.5% ± 0.3%·d–1; subadults, 1.7% ± 0.3%·d–1). A decrease in the rate of mass loss occurred after the first 3 d of fasting only in subadults during the breeding season. Percent total body lipid ranged from 11% to 28% of total body mass at the initiation of fasting trials. Animals with lower initial percent total body lipid exhibited higher subsequent rates of mass loss and a lower percentage of tissue catabolism derived from lipid reserves. There was no evidence of metabolic adaptation to fasting in juveniles, which suggests that juvenile sea lions would be more negatively impacted by food limitation during the breeding season than would subadults.

Effects of a daily mixed nutritional supplement on physical performance, body composition, and circulating anabolic hormones during 8 weeks of arduous military training

2011 ◽  
Vol 36 (6) ◽  
pp. 967-975 ◽  
Author(s):  
Matthew B. Fortes ◽  
Bethany C. Diment ◽  
Julie P. Greeves ◽  
Anna Casey ◽  
Rachel Izard ◽  
...  
Keyword(s):  
Body Composition ◽  
Mass Loss ◽  
Physical Performance ◽  
Body Mass ◽  
Lean Mass ◽  
Vertical Jump ◽  
Military Training ◽  
Nutritional Supplement ◽  
Blood Analysis ◽  
Anabolic Hormones

The aim of this work was to investigate the effect of a daily mixed nutritional supplement upon body composition, physical performance, and circulating anabolic hormones in soldiers undergoing arduous training. Thirty males received either a habitual diet alone (CON, n = 15) or with the addition of a daily mixed supplement (SUP, n = 15) of ∼5.1 MJ·d–1 during 8 weeks of training. Body composition (DEXA), maximal dynamic lift strength (MDLS), and vertical jump (VJ) were assessed, and resting blood samples were collected before and after training. Blood analysis included insulin-like growth factors (IGF-1, IGF BP-1, and IGF BP-3), testosterone, and cortisol. There were no group differences at baseline. Body mass loss (mean ± SD) (CON 5.0 ± 2.3, SUP 1.6 ± 1.5 kg), lean mass loss (CON 2.0 ± 1.5, SUP 0.7 ± 1.5 kg), and fat mass loss (CON 3.0 ± 1.6, SUP 0.9 ± 1.8 kg) were significantly blunted by SUP. CON experienced significant decrements in MDLS (14%), VJ (10%), and explosive leg power (11%) that were prevented by SUP. Military training significantly reduced circulating IGF-1 (28%), testosterone (19%), and the testosterone:cortisol ratio (24%) with no effect of SUP. Circulating IGF BP-1 concentration and cortisol remained unchanged throughout, although SUP abolished the significant decrease in circulating IGF BP-3 (20%) on CON. In conclusion, a daily mixed nutritional supplement attenuated decreases in body mass and lean mass and prevented the decrease in physical performance during an arduous military training program.

scholarly journals The Effects of Rapid Body Mass Loss on Body Composition and Athletic Performance in Combat Sports Athletes

2020 ◽  
Vol 07Sp (1) ◽  
Author(s):  
Hakan Yarar ◽  
◽  
Anil Aliyazicioglu ◽  
Yahya Eylenoglu ◽  
Ridvan Enes Aydin ◽  
...  
Keyword(s):  
Body Composition ◽  
Mass Loss ◽  
Body Mass ◽  
Athletic Performance ◽  
Combat Sports ◽  
Body Mass Loss

Duration of lactation and postweaning changes in mass and body composition of harbour seal, Phoca vitulina, pups

1993 ◽  
Vol 71 (7) ◽  
pp. 1405-1414 ◽  
Author(s):  
M. M. C. Muelbert ◽  
W. D. Bowen
Keyword(s):  
Body Composition ◽  
Energy Density ◽  
Mass Loss ◽  
Body Mass ◽  
Deuterium Oxide ◽  
Average Energy ◽  
Phoca Vitulina ◽  
Low Energy ◽  
Harbour Seal ◽  
Average Energy Density

We studied changes in body mass and body composition of harbour seal pups from weaning to 5 – 6 weeks postweaning in June – August 1988 and 1989 on Sable Island, Canada. Known-age pups (n = 52) were captured at 3-day intervals from late lactation through about 40 days postweaning. Pups were weaned, on average, at 24.1 ± 0.44 days (mean ± SE) postpartum at a body mass of 24.9 ± 0.45 kg. There were no significant differences between years or sexes in the age and mass at weaning or in the rate of mass loss during the postweaning period. The duration of the postweaning fast averaged from 15 – 17 days as assessed by stomach lavage. The rate of mass loss was independent of weaning mass. At weaning, pups contained an average of 47.7% water and 32.8% fat, based on deuterium oxide dilution. During the first 14 days postweaning, the estimated body composition of pups did not change, despite the loss of body mass. Over the next 26 days, the estimated percent body water increased to about 63% and body fat declined to about 12%. The average energy density of harbour seal pups at weaning was low (16.3 kJ/g) compared with that of other phocids (17.7 – 22.2 kJ/g). This low energy density at weaning may reflect the highly aquatic and precocial development of harbour seal pups.

Ringed seal diving behavior in the breeding season

1996 ◽  
Vol 74 (8) ◽  
pp. 1547-1555 ◽  
Author(s):  
Brendan P. Kelly ◽  
Douglas Wartzok
Keyword(s):  
Breeding Season ◽  
Light Level ◽  
Dive Depth ◽  
Dive Duration ◽  
Ringed Seal ◽  
Diving Behavior ◽  
Adult Males ◽  
Phoca Hispida ◽  
Oxygen Stores ◽  
Lactating Females

The behavior of 14 ringed seals (Phoca hispida) diving under shore-fast sea ice was monitored acoustically during the spring breeding season. Frequent dives with extended periods at depth by subadult and adult seals, including lactating females, were interpreted to be foraging dives. Median dive durations were less than 10.0 min for all seals, and the maximal observed duration was 26.4 min. The maximal observed dive depth, 222 m, was limited by water depth in the study area. Modal dive depths were between 10 and 45 m for breeding-age males and between 100 and 145 m for subadult males and postparturient females. Median dive durations were 4.0 min for adult males and 7.5 min for adult females. Body mass was a better predictor of maximal dive duration (r2 = 0.94) than was age, but maximal durations were shorter than were predicted using measures of oxygen stores and presumed metabolic rates. There was no consistent relationship between light level and the frequency or depth of dives.

Seasonal changes in buoyancy and diving behaviour of adult grey seals

2000 ◽  
Vol 203 (15) ◽  
pp. 2323-2330 ◽  
Author(s):  
C.A. Beck ◽  
W.D. Bowen ◽  
S.J. Iverson
Keyword(s):  
Body Mass ◽  
Seasonal Changes ◽  
Dive Depth ◽  
Dive Duration ◽  
Diving Behaviour ◽  
Temporal Separation ◽  
Body Fat Content ◽  
Phocid Seals ◽  
Negative Buoyancy ◽  
Negatively Buoyant

Phocid seals go through dramatic seasonal changes in body mass and composition as a result of the spatial and temporal separation of foraging, reproduction and moulting. These changes in body fat content and body mass result in seasonal changes in buoyancy, which in turn may influence diving behaviour. We examined the longitudinal changes in buoyancy and diving behaviour of 14 adult grey seals (Halichoerus grypus) during two periods that represent maximal contrast in body mass and composition. During both the post-moulting (PM) and pre-breeding (PB) periods, grey seals were negatively buoyant. However, buoyancy increased by 47.9 % between the PM and PB periods. Descent rate was significantly faster during the PM period (1.0+/−0.07 m s(−1)) than during the PB period (0.7+/−0.06 m s(−1)), suggesting that seals were aided by negative buoyancy during the downward portion of dives. Ascent rate was also significantly faster during the PM period (0.8+/−0.06 m s(−1)) than during the PB period (0.6+/−0.05 m s(−1)), contradicting the prediction that more buoyant animals should ascend faster. The effects of drag could not account for this discrepancy. Dive depth and surface interval between dives did not differ significantly between the two periods. Similarly, the distribution of dive shapes used by individuals did not differ between the two periods. However, dive duration was significantly longer during the PB period than during the PM period (5.5+/−0.25 min compared with 4.4+/−0.24 min, respectively) as was time spent at the bottom of the dive (3.1+/−0.22 min compared with 2.5+/−0.15 min, respectively).

Effects of fasting and refeeding on body composition of captive gray wolves (Canis lupus)

1997 ◽  
Vol 75 (9) ◽  
pp. 1549-1552 ◽  
Author(s):  
T. J. Kreeger ◽  
G. D. DelGiudice ◽  
L. D. Mech
Keyword(s):  
Body Composition ◽  
Body Mass ◽  
Canis Lupus ◽  
Tritiated Water ◽  
Base Line ◽  
Prolonged Fasting ◽  
Blood Samples ◽  
Gray Wolves ◽  
Fasting And Refeeding ◽  
Water Dilution

We examined the effects of fasting and refeeding on body composition in 9 captive adult gray wolves, Canis lupus (6 males, 3 females), during May–June 1995. Body composition was estimated by the technique of tritiated water dilution. Wolves were immobilized and weighed, base-line blood samples were taken, tritiated water was injected, and additional blood samples were taken before fasting, after 10 d of fasting, and again after 2 d of refeeding. Male wolves lost 8% (P = 0.0001) and females lost 7% body mass (P = 0.01) during the 10 d. Males lost 54% of this mass in water, 28% in fat, and 18% in protein/ash; females lost 58% in water, 20% in fat, and 22% in protein/ash. Upon refeeding, male wolves consumed an average of 6.8 kg (15.3% body mass) of deer meat per day and females consumed 6.4 kg (18.7% body mass). All wolves regained their initial mass. Males regained 24% of this mass in water, 70% in fat, and 6% in protein/ash; females regained 35% in water, 51% in fat, and 14% in protein/ash. This study provided evidence that after prolonged fasting, captive wolves could quickly and efficiently regain lost body mass after refeeding.

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