Maternal behaviour and energy investment by grey seals (Halichoerus grypus) breeding on land-fast ice

1996 ◽  
Vol 74 (8) ◽  
pp. 1531-1541 ◽  
Author(s):  
Martha A. Haller ◽  
Kit M. Kovacs ◽  
Mike O. Hammill
Keyword(s):  
Mass Transfer ◽  
Mass Loss ◽  
Breeding Season ◽  
Breeding Habitat ◽  
Halichoerus Grypus ◽  
Maternal Behaviour ◽  
Similar Amount ◽  
Lactation Period ◽  
Energy Investment ◽  
Fast Ice

The grey seal (Halichoerus grypus) is a sexually dimorphic polygynous phocid that breeds in a synchronous fashion, within populations, on both sides of the North Atlantic Ocean. This study was designed to examine factors that may influence maternal behaviour and energy investment of females breeding on land-fast ice. The study was conducted on the ice around Amet Island, Nova Scotia, during the breeding seasons of 1992, 1993, and 1994. Scan sampling and ad libitum observation techniques were used to record behaviour. Mass transfer from mothers to pups was determined using serial mass records for pairs. Rate of pup mass gain was 2.5 ± 0.6 kg/day and pup mass at weaning 50.0 ± 7.3 kg. The duration of lactation was 15.2 ± 1.6 days. Maternal mass at parturition was 210.6 ± 23.8 kg and female mass loss during the lactation period was 75.0 ± 16.0 kg. This mass loss represented 35.7 ± 6.1% of their parturition mass. Efficiency of mass transfer was 0.52 ± 0.12. Breeding habitat influenced maternal behaviour. Compared with land-breeding grey seals, ice-breeding females had an intensified nursing period, during which females transferred a similar amount of energy to their pups over a shorter time frame. Additionally, females on land-fast ice gave birth more synchronously than is the case in land-breeding colonies. Date of parturition within the breeding season had some influence on female behaviour; females giving birth late in the season were more active than females breeding earlier. The behaviour of males may play a role in determining the optimum time for birthing. Adult males spent more time engaged in agonistic behaviours late in the breeding season and the resultant disruption of adjacent females may serve as a selective force maintaining birthing synchrony. These influences also apply in land-breeding situations and are not likely to contribute to the contraction of the nursing period and the more synchronous breeding observed among females on ice. The more condensed lactation and birthing periods are likely a response to the higher risk of premature separation on the ice.

Mass Loss and Mass Transfer in Algols

1980 ◽  
pp. 207-210
Author(s):  
G. Giuricin ◽  
F. Mardirossian ◽  
M. Mezzetti
Keyword(s):  
Mass Transfer ◽  
Mass Loss

scholarly journals Mass Loss and Shell Masses of Close Binary Stars

1987 ◽  
Vol 93 ◽  
pp. 675-679
Author(s):  
V.G. Karetnikov
Keyword(s):  
Mass Transfer ◽  
Mass Loss ◽  
Binary Stars ◽  
Transfer Rate ◽  
Mass Transfer Rate ◽  
Close Binary ◽  
Time Interval ◽  
Close Binary Stars

AbstractFrom the values of period changes for 6 close binary stars the mass transfer rate was calculated. Comparing these values Mt with the values of shell masses Msh, the expressionwas derived. The analysis of this expression points out the initial character of the outflow of matter, and one may determine the time interval of the substitution of the shell matter. So one may conclude that for a certain mass transfer rate, a certain amount of matter accumulates in the nearby regions of the system.

scholarly journals Secular Mass Loss from Cataclysmic Variables

1977 ◽  
Vol 42 ◽  
pp. 365-370
Author(s):  
Józef Smak
Keyword(s):  
Mass Transfer ◽  
Angular Momentum ◽  
Chemical Composition ◽  
Mass Loss ◽  
Cataclysmic Variables ◽  
Dynamical Evolution ◽  
Good Insight ◽  
Physical Mechanisms ◽  
Cataclysmic Binaries ◽  
Insight Into

The mass loss from cataclysmic binaries seems an important and worth studying phenomenon for a number of reasons. It is probably enough to mention only two of them:(a) Whenever we can directly observe the ejected material, determine its amount and the rate of mass loss, as well as its chemical composition (this being the case of the expanding envelopes of novae), we are getting a good insight into the basic physical mechanisms responsible for the observed phenomena.(b) The mass loss (together with the mass transfer) and the loss of the orbital angular momentum are related directly to the dynamical evolution of a binary system and - indirectly - to the evolution of its components.

scholarly journals Do Barrow's Goldeneyes, Bucephala islandica, Breed South of the St. Lawrence Estuary in the Gaspé Peninsula, Eastern Canada?

2010 ◽  
Vol 124 (2) ◽  
pp. 179
Author(s):  
Jean-François Ouellet ◽  
Pierre Fradette ◽  
Isabel Blouin
Keyword(s):  
North America ◽  
Breeding Season ◽  
Breeding Habitat ◽  
Eastern North America ◽  
Eastern Canada ◽  
Lawrence Estuary ◽  
North Shore ◽  
The North ◽  
Bucephala Islandica ◽  
St Lawrence Estuary

We report the first observations of Barrow's Goldeneyes south of the St. Lawrence estuary in typical breeding habitat during the breeding season. Until recently, the confirmed breeding locations for the species in Eastern North America were all located on the north shore of the Estuary and Gulf of St. Lawrence.

scholarly journals IUE Observations of the Two Peculiar Binary Systems Beta Lyrae and Upsilon Sagittarii

1980 ◽  
Vol 88 ◽  
pp. 271-286 ◽  
Author(s):  
Margherita Hack ◽  
Umberto Flora ◽  
Paolo Santin
Keyword(s):  
Mass Transfer ◽  
Mass Loss ◽  
Radial Velocity ◽  
Effective Temperature ◽  
Binary Systems ◽  
Close Binaries ◽  
Infrared Excess ◽  
Show Evidence ◽  
The Common ◽  
Ultraviolet Observations

The common peculiarities of these two systems are: a) the companion is a massive object (probably m2≥10) whose spectrum is not observable; b) both systems show evidence, though in different degrees, of mass-transfer and mass-loss; c) both present, in different degrees, hydrogen deficiency; d) ultraviolet observations have shown, in both cases, the presence of lines of highly ionized elements like N V, C IV, Si IV, probably formed in an extended envelope because they do not show orbital radial velocity shifts, and cannot be explained by the effective temperature of the star whose spectrum we observe. The latter property seems to be common to several close binaries, as shown by the ultraviolet observations with IUE by Plavec and Koch (1979); e) both systems present infrared excess, suggesting the presence of an extended envelope (Gehrz et al. 1974; Lee and Nariai, 1967; Humphreys and Ney, 1974; Treffers et al. 1976).

scholarly journals Algols as Limits on Binary Evolution Scenarios

1989 ◽  
Vol 107 ◽  
pp. 155-164
Author(s):  
M.S. Hjellming
Keyword(s):  
Mass Transfer ◽  
Mass Loss ◽  
Initial Mass ◽  
Transfer Rates ◽  
Successful Transition ◽  
Evolutionary State ◽  
Mass Ratios ◽  
Binary Evolution ◽  
Do So

AbstractEvolutionary scenarios must account for Algol binaries surviving their first phase of mass transfer. The outcome of this phase is dependent upon the rapidity of the initial mass transfer, which can be estimated by calculating the radial reponse of potential progenitors to mass loss. Limits on the donor’s evolutionary state, and its companion mass, can be placed on systems which would transfer mass on a thermal or dynamical timescale. Slower mass transfer rates are necessary for the successful transition to an Algol. Considering 1.5 and 5.0 M⊙ models, the former succeed in case A and Br systems, while the latter can do so only in case A systems. To evolve into an Algol binary, all systems seem to require initial mass ratios near one.

scholarly journals The Theory of Novae and Nova-Like Systems

1974 ◽  
Vol 66 ◽  
pp. 155-167
Author(s):  
John Faulkner
Keyword(s):  
Mass Transfer ◽  
Angular Momentum ◽  
Mass Loss ◽  
Gravitational Radiation ◽  
Theoretical Work ◽  
Observational Evidence ◽  
Recent Theoretical Work ◽  
Term Response ◽  
Theoretical Developments

Recent observational and theoretical developments in the study of novae, particularly dwarf novae, are discussed. Mechanisms promoting mass transfer include (i) nuclear evolution or (ii) envelope instability of the red star and (iii) gravitational radiation of orbital angular momentum. Growing observational evidence against (ii) is supported by recent theoretical work on the medium and long term response of stellar radii to mass loss. Mechanisms (i) and (iii) may operate alone or in concert, depending on the circumstances.

scholarly journals Mass Transfer Rates in Algol Binaries Deduced from Their Period Changes

1976 ◽  
Vol 73 ◽  
pp. 283-288
Author(s):  
D. S. Hall ◽  
S. G. Neff
Keyword(s):  
Mass Transfer ◽  
Mass Loss ◽  
Period Change ◽  
Thermal Mass ◽  
Change Model ◽  
Transfer Rates ◽  
Average Mass ◽  
Mass Outflow ◽  
Loss Rates

Average mass transfer rates in 23 Algol binaries are derived by analyzing their observed period changes within the framework of the Biermann-Hall period change model. These are compared with thermal mass loss rates computed from the dimensions which the cooler (mass-losing) component had at the onset of mass outflow. The agreement is quite good and confirms a claim made earlier that the subgiant components in Algol binaries are losing mass at a rapid (thermal) rate, not at a slow (nuclear) rate.

scholarly journals Carbon Depletion in Case B Mass Transfer Algol-Type Binaries

1992 ◽  
Vol 151 ◽  
pp. 355-358
Author(s):  
Tae S. Yoon ◽  
Kent Honeycutt
Keyword(s):  
Mass Transfer ◽  
Mass Loss ◽  
Similar Type ◽  
Single Star ◽  
Star Models ◽  
Promising Tool ◽  
Carbon Abundance ◽  
Processed Material ◽  
C And N ◽  
Larger Sample

The surface carbon abundances of Algol secondaries are known to be low compared to field stars of similar type. The C and N anomalies of these G and K subgiants are undoubtedly due to the exposure of CN cycle processed material as mass transfer removes the outer layers of the star. Therefore the carbon abundance is a promising tool for helping fix the evolutionary state of Algols, particularly the amount of mass which has been lost from the secondary. We report here the carbon abundance of 12 Algol secondaries as deduced from the g-band in spectra obtained during photometric totality. We compare the abundances to those from models of single stars of appropriate age and mass. The values of log ∊(C) for this sample fall 0.25–0.75 dex below field G and K giants, and 1.25–1.75 dex above “stripped” single star models. This larger sample supports the conclusions of Parthasarthy et al. regarding mixing and mass loss, which they deduced from a smaller sample of carbon abundances.

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