scholarly journals Rapid weight loss in free ranging pygmy killer whales (Feresa attenuata) and the implications for anthropogenic disturbance of odontocetes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jens J. Currie ◽  
Martin van Aswegen ◽  
Stephanie H. Stack ◽  
Kristi L. West ◽  
Fabien Vivier ◽  
...  

AbstractUnderstanding the impacts of foraging disruptions to odontocete body condition is fundamental to quantifying biological effects of human disturbance and environmental changes on cetacean populations. Here, reductions in body volume of free-ranging pygmy killer whales (Feresa attenuata) were calculated using repeated measurements of the same individuals obtained through Unoccupied Aerial System (UAS)-photogrammetry during a prolonged disruption in foraging activity arising from a 21-day stranding event. Stranded individuals were used to verify UAS-derived volume and length estimates through 3D-imaging, water displacement, and post-mortem measurements. We show that (a) UAS estimates of length were within 1.5% of actual body length and UAS volume estimates were within 10–13% of actual volume, (b) foraging disruption resulted in a daily decrease of 2% of total body mass/day, and (c) pygmy killer whales can lose up to 27% of their total body weight within 17 days. These findings highlight the use of UAS as a promising new method to remotely monitor changes in body condition and animal health, which can be used to determine the potential effects of anthropogenic disturbance and environmental change on free-ranging odontocetes.

2001 ◽  
Vol 79 (6) ◽  
pp. 955-965 ◽  
Author(s):  
Erin M Lehmer ◽  
Beatrice Van Horne

Black-tailed prairie dogs (Cynomys ludovicianus) enter torpor intermittently during winter in the field but do not hibernate continuously from fall to spring. Previous studies have established that hibernators rely primarily on stored lipids during winter and that the storage of n–6 PUFAs in white adipose tissue (WAT) is required to maintain low body temperatures during this continuous torpor. Adult (>1 year) black-tailed prairie dogs were livetrapped in the fall, winter, spring, and summer (n = 10–12). To determine whether free-ranging black-tailed prairie dogs rely heavily on stored proteins during winter, we investigated seasonal changes in body composition of the prairie dogs with dual-energy X-ray absorptiometry scans. We also examined seasonal changes in lipid composition of the WAT and diet using gas–liquid chromatography to determine whether black-tailed prairie dogs lack the lipids necessary for hibernation. Seasonal changes in fat, lean, and total body mass indicate that black-tailed prairie dogs relied heavily on stored lipids during the winter and appeared to rely on proteins primarily during periods that coincided with reproductive activity. Seasonal changes in dietary and WAT lipids indicate that WAT n–6 PUFAs are used during winter and stored during summer, while WAT n–3 PUFAs are stored during winter and used during summer. These patterns of lipid use are different than those reported in free-ranging hibernators and may explain why black-tailed prairie dogs experience shallow and infrequent torpor bouts.


2014 ◽  
Vol 9 ◽  
pp. 361
Author(s):  
David Griffiths ◽  
Erik W Born ◽  
Mario Acquarone

Physiological studies involving the use of isotopic water required chemical restraint of free-ranging walruses (Odobenus rosmarus) for several hours. In August 2000, six male walrus (total body mass: 1050–1550 kg) were immobilized in East Greenland by remote delivery of 8.0–9.8 mg of etorphine and subsequently restrained for up to 6.75 h by administration of medetomidine. The effects of etorphine were reversed with 10–24 mg diprenorphine. After termination of the etorphine-induced apnoea, lasting an average of 15.8 min (SD = 9.7, range = 9.5–35.2 min, n = 6), the animals were initially given 10–20 mg medetomidine intramuscularly. The initial dose was further augmented by 5 mg at intervals of 5 min. In two cases, when medetomidine was administered through a catheter inserted in the extradural vein, the animal became instantly apnoeic and regained respiratory function only after intravenous injection of the prescribed dose of the antagonist atipamezole and of the respiratory stimulant doxapram. After an average of 3.5 hours of immobilisation, rectal temperature began to increase and it is conceivable that this is the factor that will ultimately limit the duration of immobilisation. The animals became conscious and fully mobile shortly after an intravenous injection of a dose of atipamezole approximately twice the mass of the total dose of medetomidine given during the procedure followed by 400 mg of doxapram. It is concluded that medetomidine appears to be a suitable drug for chemical restraint of walruses for time-consuming procedures following initial immobilisation by etorphine. With animals of total body mass around 1,000–1,500 kg, the drug should be given intramuscularly in 10–20 mg increments (total mass 10–60 mg) until the breathing rate falls to approximately 1 min-1. At this level, breathing is maintained and animals do not respond to touch or injection.


2002 ◽  
Vol 80 (7) ◽  
pp. 1156-1161 ◽  
Author(s):  
Marc R.L Cattet ◽  
Nigel A Caulkett ◽  
Martyn E Obbard ◽  
Gordon B Stenhouse

In this investigation a body-condition index (BCI) was developed for polar bears (Ursus maritimus), black bears (Ursus americanus), and grizzly bears (Ursus arctos), based on residuals from the regression of total body mass against a linear measure of size, straight-line body length (SLBL). Transformation of mass–length data from 1198 polar bears, 595 black bears, and 126 grizzly bears to natural logarithms resulted in a linear relationship between mass and length. However, the relationship in polar bears differed from that in black and grizzly bears. SLBL had a close positive relationship with skeletal (bone) mass in polar bears (n = 31) and black bears (n = 33), validating the use of SLBL as an accurate index of body size. There was no correlation between SLBL and BCI for polar bears (r = 0.005, p = 0.87, n = 1198) or for black bears and grizzly bears (r = 0.04, p = 0.30, n = 721), indicating that the BCI was independent of body size. The BCI had a close positive relationship with true body condition, measured as the standardized residual of the combined mass of fat and skeletal muscle against SLBL, in polar and black bears that were dissected to determine individual tissue masses. The BCI also had a close positive relationship with the standardized residual of fat mass against SLBL. Estimation of BCI values for polar bears, or for black bears and grizzly bears, is facilitated by prediction equations that require measurement of total body mass and SLBL for individual animals.


1984 ◽  
Vol 16 (3-4) ◽  
pp. 399-406
Author(s):  
Y Monbet

A study was conducted to gain insight on actual sedimentological and biological effects associated with the construction of an oil Terminal designed to receive 500 000 d.w.t. tankers. Field investigations and subsequent laboratory analyses were organized to evaluate the nature and magnitude of environmental changes on benthic macrofauna, three years after the end of the construction. Sediments were found to decrease dramatically in medium grain size in area sheltered by the newly built breakwater. Increase of percentage of silt and clays (90 % against 20 %) was observed leeward of the jetty. The benthic fauna showed significant modifications. Although the same community (Pectinaria kareni Abra alba) recolonized the bottom after the dredging of up to 30 × 106 m3 of sediments, increase in abundance occured. Biomass remained at a constant level and decrease of diversity was observed. Considering the rate of siltation, and assuming a constant siltation rate equal to the rate observed from 1975 to 1978, a simple regressive model relating biomass to mean grain size of sediments has been developped. This model allowed the prediction of biomass and production of the two principal species for the period 1978 – 1981. Continuous siltation within the harbor leads to a maximum of biomass from years after the end of the construction, followed by a decrease of standing stock. This process may be explained by the respective tolerance of the two principal species to increase silt contant and also probably by the accumulation of organic matter which may impede the development of natural populations.


Ecosphere ◽  
2021 ◽  
Vol 12 (8) ◽  
Author(s):  
Joshua D. Stewart ◽  
John W. Durban ◽  
Holly Fearnbach ◽  
Lance G. Barrett‐Lennard ◽  
Paige K. Casler ◽  
...  

1983 ◽  
Vol 31 (5) ◽  
pp. 695 ◽  
Author(s):  
IJ Rooke ◽  
SD Bradshaw ◽  
RA Langworthy

Total body water content (TBW) and TBW turnover were measured by means of tritiated water (HTO) in free-ranging populations of silvereyes, Zosterops lateralis, near Margaret River, W.A. Birds were studied in their natural habitats during spring and summer, and compared with a vineyard population in summer. In the natural habitat TBW content was found to be 77.6% in spring, which was not significantly different from that measured in summer (78.3%). Birds in vineyards in summer, however, were dehydrated, with a TBW content of 69.4%. Calculated rates of water influx for spring, summer and summer vineyards birds were 1.44,2.20 and 0.65 ml g.day-' respectively. These water turnover rates are much higher than those of any other bird yet studied. Dehydration was marked in the vineyard birds, with a significantly lower TBW content and an average net water loss of 0.63 ml day-'. Laboratory studies showed that silvereyes have a low tolerance to sodium loading. Their tolerance is, however, quite adequate for them to drink the most concentrated free water available to them in the field. Ingestion of concentrated sugar solutions of up to 25% did not provoke an osmotic diuresis and thus cannot account for the dehydration and negative water balance of vineyard birds.


2004 ◽  
Vol 287 (5) ◽  
pp. E962-E969 ◽  
Author(s):  
Analiza M. Silva ◽  
Wei Shen ◽  
ZiMian Wang ◽  
John F. Aloia ◽  
Miriam E. Nelson ◽  
...  

There is renewed interest in Siri's classic three-compartment (3C) body composition model, requiring body volume (BV) and total body water (TBW) estimates, because dual-energy X-ray absorptiometry (DEXA) and in vivo neutron activation (IVNA) systems cannot accommodate subjects with severe obesity. However, the 3C model assumption of a constant ratio (α) of mineral (M) to total body protein (TBPro) and related residual mass density (DRES) based on cadaver analyses might not be valid across groups differing in sex, race, age, and weight. The aim of this study was to derive new 3C model coefficients in vivo and to compare these estimates to those derived by Siri. Healthy adults ( n = 323) were evaluated with IVNA and DEXA and the measured components used to derive α and DRES. For all subjects combined, values of α and DRES (means ± SD, 0.351 ± 0.043; 1.565 ± 0.023 kg/l) were similar to Siri's proposed values of 0.35 and 1.565 kg/l, respectively. However, α and DRES varied significantly as a function of sex, race, weight, and age. Expected errors in percent body fat arising by application of Siri's model were illustrated in a second group of 264 adults, including some whose size exceeded DEXA limits but whose BV and TBW had been measured by hydrodensitometry and 2H2O dilution, respectively. Extrapolation of predictions by newly developed models to very high weights allows percent fat error estimation when Siri's model is applied in morbidly obese subjects. The present study results provide a critical evaluation of potential errors in the classic 3C model and present new formulas for use in selected populations.


1929 ◽  
Vol 6 (4) ◽  
pp. 311-324
Author(s):  
R. CUMMING ROBB

1. Throughout post-natal life the relative weights of the pituitary body, thyroid, thymus and adrenals in the rabbit may be expressed by the equation y = axk + c. 2. A similar association is indicated in the rat for the weights of eyeballs, liver, pancreas, hypophysis, thyroid, adrenals, submaxillary glands, kidney and fresh skeleton (data from Donaldson, 1924). 3. In giant and pigmy rabbits, the ultimate proportions of body parts are not the same, but (for any given body weight) corresponding tissues in the two groups tend to exhibit an identical relation to total body mass. 4. The adrenals and testes of the Polish rabbits are relatively much larger than those of the Flemish. But in each case the growth of the adrenal approximates to a constant power function of body weight. Moreover, in these two groups and in their hybrids, the growth of the testes adheres to a simple association with adrenal weight identical for each. 5. These data suggest the generalisation that in a growing organism the magnitude of any part tends to be a specific function of the total body mass or of some portion so related to the whole. 6. These associations may be explained by surmising that each tissue is in equilibrium with the internal milieu with regard to the distribution of nutrient growth essentials; that in each case the equilibrium point would be determined by the nature of the cell and after differentiation would tend to remain constant; and that the relative enlargement of each tissue is limited by the excess of the equilibrium value over the katabolic expenditure. 7. According to the above hypothesis of organ growth, the equation y = axk + c may possess a physical significance. Eight types of growth relationships may thus exist, differing because of the apparent inactivity of one or more constants in this equation.


2021 ◽  
Vol 8 ◽  
Author(s):  
Ann Weaver

Adaptation is a biological mechanism by which organisms adjust physically or behaviorally to changes in their environment to become more suited to it. This is a report of free-ranging bottlenose dolphins’ behavioral adaptations to environmental changes from coastal construction in prime habitat. Construction was a 5-year bridge removal and replacement project in a tidal inlet along west central Florida’s Gulf of Mexico coastline. It occurred in two consecutive 2.5-year phases to replace the west and east lanes, respectively. Lane phases involved demolition/removal of above-water cement structures, below-water cement structures, and reinstallation of below + above water cement structures (N = 2,098 photos). Data were longitudinal (11 years: 2005–2016, N = 1,219 surveys 2–4 times/week/11 years, N = 4,753 dolphins, 591.95 h of observation in the construction zone, 126 before-construction surveys, 568 during-construction surveys, 525 after-construction surveys). The dependent variable was numbers of dolphins (count) in the immediate construction zone. Three analyses examined presence/absence, total numbers of dolphins, and numbers of dolphins engaged in five behavior states (forage-feeding, socializing, direct travel, meandering travel, and mixed states) across construction. Analyses were GLIMMIX generalized linear models for logistic and negative binomial regressions to account for observation time differences as an exposure (offset) variable. Results showed a higher probability of dolphin presence than absence before construction began, more total dolphins before construction, and significant decreases in the numbers of feeding but not socializing dolphins. Significant changes in temporal rhythms also revealed finer-grained adaptations. Conclusions were that the dolphins adapted to construction in two ways, by establishing feeding locations beyond the disturbed construction zone and shifting temporal rhythms of behaviors that they continued to exhibit in the construction zone to later in the day when construction activities were minimized. This is the first study to suggest that the dolphins learned to cope with coastal construction with variable adjustments.


Sign in / Sign up

Export Citation Format

Share Document