Evidence of stereotyped underwater vocalizations of male Atlantic walruses (Odobenus rosmarus rosmarus)

1987 ◽  
Vol 65 (9) ◽  
pp. 2311-2321 ◽  
Author(s):  
Ian Stirling ◽  
Wendy Calvert ◽  
Cheryl Spencer
Keyword(s):  
Breeding Season ◽  
Adult Male ◽  
Whole Body ◽  
Individual Male ◽  
Odobenus Rosmarus ◽  
Number Pattern ◽  
The Individual ◽  
Odobenus Rosmarus Rosmarus

Adult male Atlantic walruses (Odobenus rosmarus rosmarus) vocalize extensively underwater during the breeding season. The individual calls are composed of one or more short repetitious pulses which may vary individually in the number, pattern, and rate at which they are given. Individual male walruses give repeated stereotyped vocalization cycles totalling several hundred pulses each for up to several hours at a time, both while the whole body is submerged and between breaths with the head submerged while at the surface. We analyzed the vocalization cycles of a sample of different walruses, and sound spectrograms of particular calls from within those cycles, to test the hypothesis that the stereotyped vocalizations of individuals are unique and recognizable. In our sample, the pulse patterns of particular calls given by individual walruses in a series of vocalization cycles were nearly identical but were consistently different from the same call given by other animals. One call, the diving vocalization of a recognizable male, was identical in two different years.

A Simple Method for the Evaluation of Internal Doses in Nuclear Medicine

1974 ◽  
Vol 13 (02) ◽  
pp. 193-206
Author(s):  
L. Conte ◽  
L. Mombelli ◽  
A. Vanoli
Keyword(s):  
Nuclear Medicine ◽  
Close Agreement ◽  
Whole Body ◽  
Simple Method ◽  
Rapid Estimation ◽  
Absorbed Doses ◽  
The Mean ◽  
The Individual ◽  
Estimation Of Risk

SummaryWe have put forward a method to be used in the field of nuclear medicine, for calculating internally absorbed doses in patients. The simplicity and flexibility of this method allow one to make a rapid estimation of risk both to the individual and to the population. In order to calculate the absorbed doses we based our procedure on the concept of the mean absorbed fraction, taking into account anatomical and functional variability which is highly important in the calculation of internal doses in children. With this aim in mind we prepared tables which take into consideration anatomical differences and which permit the calculation of the mean absorbed doses in the whole body, in the organs accumulating radioactivity, in the gonads and in the marrow; all this for those radionuclides most widely used in nuclear medicine. By comparing our results with dose obtained from the use of M.I.R.D.'s method it can be seen that when the errors inherent in these types of calculation are taken into account, the results of both methods are in close agreement.

A TRITIATED WATER EXPERIMENT ON A MALE ATLANTIC WALRUS (ODOBENUS ROSMARUS ROSMARUS)

1992 ◽  
Vol 8 (4) ◽  
pp. 418-420 ◽  
Author(s):  
Christian Lydersen ◽  
David Griffiths ◽  
Ian Gjertz ◽  
Oystein Wiig
Keyword(s):  
Tritiated Water ◽  
Odobenus Rosmarus ◽  
Odobenus Rosmarus Rosmarus ◽  
Atlantic Walrus

The agreement between reaction-board measurements and kinematic estimation of adult male human whole body centre of mass location during running

2004 ◽  
Vol 25 (6) ◽  
pp. 1339-1354 ◽  
Author(s):  
Warrick McKinon ◽  
Craig Hartford ◽  
Luca Di Zio ◽  
Johan van Schalkwyk ◽  
Demetri Veliotes ◽  
...  
Keyword(s):  
Adult Male ◽  
Whole Body ◽  
Centre Of Mass

Summer foods of Atlantic walrus, Odobenus rosmarus rosmarus, in northern Foxe Basin, Northwest Territories

1997 ◽  
Vol 75 (7) ◽  
pp. 1166-1175 ◽  
Author(s):  
K. I. Fisher ◽  
R. E. A. Stewart
Keyword(s):  
Benthic Invertebrates ◽  
Stomach Contents ◽  
Male And Female ◽  
Foxe Basin ◽  
Important Prey ◽  
Odobenus Rosmarus ◽  
Serripes Groenlandicus ◽  
Gross Energy ◽  
Odobenus Rosmarus Rosmarus ◽  
Atlantic Walrus

Stomach contents of Atlantic walrus, Odobenus rosmarus rosmarus, taken by Inuit hunters in northern Foxe Basin in July 1987 and 1988 (n = 105) and September 1988 (n = 2) were examined. In July, 20 of 94 stomachs from immature and adult walrus contained > 5 g of food representing 17 prey taxa, including bivalves, gastropods, holothurians, polychaetes, and brachiopods. The bivalve Mya truncata contributed 81.4% of the total gross energy in the diet, with the bivalve Hiatella arctica, holothurians, and the polychaete Nereis sp. contributing 7.5, 3.5, and 2.8%, respectively. The diets of male and female walrus were similar except that females received a significantly (P < 0.05) greater percentage of gross energy in their diet from H. arctica than did males. Walrus less than 3 years old (n = 11) consumed mostly milk, although some benthic invertebrates were eaten. Analysis of the contents of two stomachs collected in September suggested that walrus may feed more intensively in the fall. Mya truncata was again the predominant prey, contributing 59.9% of total gross energy, with the bivalve Serripes groenlandicus (37.9%) replacing H. arctica (0.3%) as the second most important prey.

scholarly journals Management of Atlantic walrus (Odobenus rosmarus rosmarus) in the arctic Atlantic

2014 ◽  
Vol 9 ◽  
pp. 315 ◽  
Author(s):  
Øystein Wiig ◽  
Erik W Born ◽  
Robert EA Stewart
Keyword(s):  
Environmental Protection ◽  
Large Scale ◽  
Anthropogenic Impacts ◽  
Current Control ◽  
Arctic Sea Ice ◽  
The Arctic ◽  
Arctic Canada ◽  
Quota System ◽  
Odobenus Rosmarus ◽  
Odobenus Rosmarus Rosmarus

We review the management of Atlantic walruses (Odobenus rosmarus rosmarus) past and present in the four range states—Canada, Greenland, Norway and Russia—which have permanent populations of Atlantic walruses. Populations in all four countries have been depleted, although the extent of depletion is not well known. Inuit in Arctic Canada and Greenland hunt Atlantic walruses for subsistence while they have been protected at Svalbard (Norway) since 1952 and in the western Russian Arctic since 1956. Since the second half of the 20th Century Canada and Greenland have increased protection of their walrus. Generally the number of walruses landed in Canada is governed by the number of hunters and/or people in the settlement and not by stock-specific quotas. Although quotas have been set in few communities, it is not known if they are adequate to prevent overhunting. A quota system for walrus hunting in Greenland began in 2006. The current control system is largely effective in ensuring the quotas are applied and that reporting is correct. Greenland currently sets quotas based on recommendations from scientific assessments using recent population estimates to allow population growth from a depleted population.  A challenge with respect to managing walrus hunting remains the variable and sometimes high rates of lost animals. Since the 1960s changes in socio-economics in hunting areas of Arctic Canada and Greenland (and the use of snowmobiles instead of dog sleds in Canada) have led to a general decrease in interest in hunting of walruses and reduced harvest on walrus stocks in these countries. Although there is an active ongoing cooperation between Canada and Greenland scientists regarding assessments of shared populations of walruses currently there is no formal agreement between the two range states on co-management of shared stocks. Protection of walrus from other anthropogenic impacts generally focusses on large-scale industrial activity. The level of protection afforded to walrus habitat in many areas depends entirely on the rigor with which the Environmental Impact Assessments are conducted. Basic information on walrus such as numbers and stock discreteness is often lacking and sufficient lead-time is required to collect baseline data. Moreover, although most environmental protection legislation considers ‘cumulative impacts’, practical application remains problematic. The effectiveness of environmental protection regulations depends on industry compliance and the management authorities’ ability to enforce compliance. Because walrus are found in remote locations, enforcement remains a challenge. Increased human activity allowed by the current change in distribution and quality of arctic sea ice poses new threats to walrus if not well regulated. International agreements have varying importance for management within and among member states. Regulations governing international trade serve to identify illegally obtained products and to encourage range states to have a sustainable quota system. International cooperation in information sharing has had clear benefits for management of walruses in the past. The maintenance and expansion of these international efforts will improve the management of Atlantic walruses in the future. 

Influence of juvenile housing conditions on the ventilatory, thermoregulatory, and endocrine responses to hypoxia of adult male rats

2011 ◽  
Vol 111 (2) ◽  
pp. 516-523 ◽  
Author(s):  
Sébastien Fournier ◽  
Vincent Joseph ◽  
Richard Kinkead
Keyword(s):  
Adult Male ◽  
Maternal Separation ◽  
Corticosterone Level ◽  
Plasma Corticosterone ◽  
Male Rats ◽  
Whole Body ◽  
Housing Conditions ◽  
Juvenile Period ◽  
Hypoxic Conditions ◽  
Respiratory Plasticity

“Extreme” housing conditions, such as isolation (single housing) or crowding, are stressful for rats, and their deleterious impact on behavior is well documented. To determine whether more subtle variations in housing can affect animal physiology, the present study tested the hypothesis that the hypoxic ventilatory response (HVR) of adult male rats housed in pairs during the juvenile period (postnatal day 21 to adulthood) does not differ from that of animals housed in triads. Because neonatal stress augments the neuroendocrine responsiveness to stress and HVR, experiments were performed both on “control” (undisturbed) animals and rats subjected to neonatal maternal separation (NMS; 3 h/day, postnatal days 3–12). At adulthood, ventilatory activity was measured by whole body plethysmography under normoxic and hypoxic conditions (inspired fraction of O2 = 0.12; 20 min). The ventilatory and body temperature responses to hypoxia of rats raised in triads were less than those of rats housed in pairs. For the HVR, however, the attenuation induced by triad housing was more important in NMS rats. Triad housing decreased “basal” plasma corticosterone, but increased estradiol and testosterone levels. Much like the HVR, housing-related decrease in corticosterone level was greater in NMS than control rats. We conclude that modest changes in housing conditions (pairs vs. triads) during the juvenile period can influence basic homeostatic functions, such as temperature, endocrine, and respiratory regulation. Housing conditions can influence (even eliminate) the manifestations of respiratory plasticity subsequent to deleterious neonatal treatments. Differences in neuroendocrine function likely contribute to these effects.

scholarly journals Changes in energy expenditure during the menstrual cycle

1989 ◽  
Vol 61 (2) ◽  
pp. 187-199 ◽  
Author(s):  
J. T. Bisdee ◽  
W. P. T. James ◽  
M. A. Shaw
Keyword(s):  
Menstrual Cycle ◽  
Energy Expenditure ◽  
Metabolic Rate ◽  
Whole Body ◽  
Basal Body Temperature ◽  
Late Luteal Phase ◽  
Excretion Rates ◽  
The Individual ◽  
Late Follicular Phase ◽  
Exercise Efficiency

1. Eight women were studied under metabolic-ward conditions while consuming a constant diet throughout a single menstrual cycle. Basal body temperature, salivary and urinary hormone concentrations were used in monitoring the cycle and designing the study so that whole-body calorimetry for 36 h was conducted at four phases of the cycle in relation to the time of ovulation.2. The metabolic rate during sleep showed cyclical changes, being lowest in the late follicular phase and highest in the late luteal phase. The increase amounted to 6.1 (SD 2.7)%. Energy expenditure (24 h) also increased but the change was not statistically significant (P> 0.05). Exercise efficiency did not change during the cycle.3. There were no significant changes in plasma thyroxine, 3, 5, 3'-triiodothyronine or free 3, 5, 3'-triiodothyronine concentrations to explain the metabolic rate changes; nor did they relate to urinary luteinizing hormone, pregnanediol-3α-glucuronide or oestrone-3-glucuronide excretion rates. No link with salivary cortisol or progesterone concentrations was observed, but there was a small inverse relation between the individual increase in sleeping metabolic rate and the subjects' falling ratio of urinary oestrone-3-glucuronide: pregnanediol-3α-glucuronide.

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