Body mass loss of moulting female southern elephant seals, Mirounga leonina, at Macquarie Island

Polar Biology ◽  
1994 ◽  
Vol 14 (4) ◽  
Author(s):  
MarkA. Hindell ◽  
DavidJ. Slip ◽  
HarryR. Burton
Keyword(s):  
Mass Loss ◽  
Body Mass ◽  
Mirounga Leonina ◽  
Body Mass Loss ◽  
Elephant Seals ◽  
Macquarie Island ◽  
Southern Elephant Seals

Body-Mass Loss, Utilization of Blubber and Fat, and Energetic Requirements of Male Southern Elephant Seals, Mirounga-Leonina, During the Molting Fast

1992 ◽  
Vol 40 (3) ◽  
pp. 235 ◽  
Author(s):  
DJ Slip ◽  
NJ Gales ◽  
HR Burton
Keyword(s):  
Energy Expenditure ◽  
Mass Loss ◽  
The Body ◽  
Relative Distribution ◽  
Mirounga Leonina ◽  
Body Mass Loss ◽  
Elephant Seals ◽  
Southern Elephant Seals ◽  
The Mean ◽  
Body Energy

The energetic requirements of male southern elephant seals, Mirounga leonina, were estimated from mass loss, and changes in blubber mass determined by ultrasound in 11 seals over the moulting fast. Mean rate of mass loss was 9.60+/-2.25 kg day-1 or 6.46+/-0.77 g kg-1 day-1, with about 63% of this lost as fat. Blubber was depleted by about 48% over the moulting period. The relative distribution of blubber remained unchanged after the moult, and seals lost blubber at similar rates over all areas of the body. Energy expenditure was estimated to be 7.54+/-82 MJ kg-1 over the mean 35.6-day moulting period.

Growth of Southern Elephant Seals, Mirounga leonina, during their First Foraging Trip

1997 ◽  
Vol 45 (5) ◽  
pp. 447 ◽  
Author(s):  
Cameron M. Bell ◽  
Harry R. Burton ◽  
Mark A. Hindell
Keyword(s):  
Body Composition ◽  
Body Size ◽  
Body Mass ◽  
First Year ◽  
Mirounga Angustirostris ◽  
Mirounga Leonina ◽  
Elephant Seals ◽  
Southern Elephant Seals ◽  
First Year Of Life ◽  
Foraging Skills

A longitudinal study of growth of southern elephant seals, Mirounga leonina, during their first foraging trip was undertaken at Macquarie Island. On average, body mass increased by 75% while foraging at sea, with individuals growing at 0.34 ± 0.12 (s.d.) kg day-1 (n = 64), and spending 182 ± 51 days (n = 64) at sea. Relatively smaller changes in body length were recorded during the same period, suggesting that growth was composed primarily of adjustments to body composition, rather than increases in gross body size. This may be in response to the functional demands of pelagic life. Body size established early in life (birth mass and departure mass) positively influenced body mass upon return from the first foraging trip. Growth rate, however, was negatively related to departure mass for females, and this is hypothesised to be related to sex differences in body composition, as well as intrasex differences in foraging skills, diving ability and food- conversion efficiency. Despite this, there was no detectable age-specific sexual dimorphism in the first year of life. Animals that were at sea longer tended to return in better body condition. Interspecific comparison suggests that southern elephant seals grow more than do northern elephant seals, Mirounga angustirostris, and this difference may be related to prey abundance and distribution.

Growth of female southern elephant seals Mirounga leonina at Macquarie Island

Polar Biology ◽  
2005 ◽  
Vol 28 (5) ◽  
pp. 395-401 ◽  
Author(s):  
Cameron M. Bell ◽  
Harry R. Burton ◽  
Mary-Anne Lea ◽  
Mark A. Hindell
Keyword(s):  
Mirounga Leonina ◽  
Elephant Seals ◽  
Macquarie Island ◽  
Southern Elephant Seals

Migrations and foraging of juvenile southern elephant seals from Macquarie Island within CCAMLR managed areas

2002 ◽  
Vol 14 (2) ◽  
pp. 134-145 ◽  
Author(s):  
John van den Hoff ◽  
Harry R. Burton ◽  
Mark A. Hindell ◽  
Michael D. Sumner ◽  
Clive R. McMahon
Keyword(s):  
Foraging Ecology ◽  
Polar Front ◽  
Commercial Fishing ◽  
Antarctic Polar Front ◽  
Mirounga Leonina ◽  
Elephant Seals ◽  
Macquarie Island ◽  
Location Data ◽  
Southern Elephant Seals ◽  
The Antarctic

Twenty-three juvenile (8–14 months of age) southern elephant seals (Mirounga leonina L.) from Macquarie Island were tracked during 1993 and 1995. Migratory tracks and ocean areas with concentrated activity, presumed to be foraging grounds, were established from location data gathered by attached geolocation-time depth recorders. The seals ranged widely (811–3258 km) and foraging activity centred on oceanographic frontal systems, especially the Antarctic Polar Front and bathymetric features such as the Campbell Plateau region. The seals spent 58.6% of their sea time within managed fishery areas while the remainder was spent on the high seas, an area of unregulated fishing. The Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) areas 58.4.1, 88.2 and especially 88.1 were important and distant foraging areas for these juvenile elephant seals. From fisheries records, diet and the foraging ecology studies of the seals there appears to be little, if any, overlap or conflict between the seals and commercial fishing operations within the regulated commercial areas. However, attention is drawn to the possibility of future interactions if Southern Ocean fisheries expand or new ones commence.

First-year survival of southern elephant seals, Mirounga leonina , at sub-Antarctic Macquarie Island

Polar Biology ◽  
1999 ◽  
Vol 21 (5) ◽  
pp. 279-284 ◽  
Author(s):  
Clive R. McMahon ◽  
Harry R. Burton ◽  
Marthan N. Bester
Keyword(s):  
First Year ◽  
Mirounga Leonina ◽  
Elephant Seals ◽  
Macquarie Island ◽  
Southern Elephant Seals

Dispersal of southern elephant seals (Mirounga leonina L.) marked at Macquarie Island

2001 ◽  
Vol 28 (4) ◽  
pp. 413 ◽  
Author(s):  
John van den Hoff
Keyword(s):  
Island Population ◽  
Mirounga Leonina ◽  
Elephant Seals ◽  
Macquarie Island ◽  
North East ◽  
The North ◽  
Southern Elephant Seals ◽  
Juvenile Population ◽  
Maximum Proportion ◽  
Campbell Island

Southern elephant seals marked at Macquarie Island disperse to distant locations where they are sometimes seen during their moult and, for juveniles, a mid-year haul-out period (July–August). Most (87%) of these resighted seals were within 1000 km of Macquarie Island, and most commonly at Campbell Island (700 km to the north-east). The sex and age classes most likely to disperse there were males less than two years old. Male elephant seals of all ages were resighted significantly more often than females, the ratio being 2 : 1 (P > 0.05). Migration duration tended to increase with the seals’ age but migration distance was underestimated from resight observations when compared with known telemetry records. Emigration from the Macquarie Island population appears limited. From the resight effort at Campbell Island during 1995 the maximum proportion of the juvenile population from Macquarie Island to haul-out at Campbell Island was in the order of 0.0053.

Age in relation to Breeding to Status of the Male Southern Elephant Seal, Mirounga leonina (L.), at Macquarie Island

1981 ◽  
Vol 8 (2) ◽  
pp. 327 ◽  
Author(s):  
E Jones
Keyword(s):  
Elephant Seal ◽  
Progressive Increase ◽  
Southern Elephant Seal ◽  
Mirounga Leonina ◽  
Elephant Seals ◽  
Macquarie Island ◽  
Southern Elephant Seals ◽  
Definition Of ◽  
Breeding Seasons ◽  
Breeding Status

Records of the breeding status of known-age male southern elephant seals at Macquarie I. were kept during five breeding seasons between 1969 and 1976. The seven status categories used were: beachmaster, secure assistant, medium harem owner, insecure assistant, small harem owner, attending bachelor, avoiding bachelor. There was a progressive increase in breeding status with age; none younger than 10-y-old bred: 16% of 10-y-olds, 30% of 11-y-olds and 55% of 12-y-olds did so; none younger than 12-y-old attained secure assistant status. At the earliest, beachmaster status may be attained at 14 y old, but no beachmasters of known age were recorded. Due to mortality and competition, most males do not breed and few breed for more than two seasons. Problems associated with the precise definition of status categories are discussed.

Origins, age composition and change in numbers of moulting southern elephant seals (Mirounga leonina L.) in the Windmill Islands, Vincennes Bay, east Antarctica, 1988 - 2001

2003 ◽  
Vol 30 (3) ◽  
pp. 275 ◽  
Author(s):  
John van den Hoff ◽  
Rupert Davies ◽  
Harry Burton
Keyword(s):  
Mature Male ◽  
East Antarctica ◽  
Mirounga Leonina ◽  
Age Classes ◽  
Age Composition ◽  
Elephant Seals ◽  
Macquarie Island ◽  
Heard Island ◽  
Southern Elephant Seals ◽  
Windmill Islands

We discovered that the number of male southern elephant seals (Mirounga leonina) moulting at wallow sites in the Windmill Islands, Vincennes Bay, Antarctica has decreased by 88% since the last data were presented in 1989. This figure equates to an annual decrease of 6.5%, a figure quite different to the known population trends at the islands from where the seals originate. The seals inhabited four fewer wallows in 2001 than in 1990. Brand and tag resights confirm that seals moulting at Browning Peninsula and Peterson Island originate from Macquarie Island and Heard Island. Male seals aged 1–7+ years of age were present but most (68%) were aged over 7. Males aged 4 years old began to haul out in mid-February while prior to that time only male seals older than 5 years were seen. Timing of moult for particular age classes was similar to that observed at other breeding islands. Trends in the numbers of adolescent and mature male seals hauled out at the sub-antarctic breeding locations require investigation.

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