scholarly journals Spatial variation in female southern elephant seal mass change assessed by an accurate non-invasive photogrammetry method

2013 ◽  
Vol 25 (6) ◽  
pp. 731-740 ◽  
Author(s):  
Martin Postma ◽  
Marthán N. Bester ◽  
P.J. Nico De Bruyn
Keyword(s):  
Life Cycle ◽  
Mass Loss ◽  
Marine Mammals ◽  
Three Dimensional ◽  
Elephant Seal ◽  
Southern Elephant Seal ◽  
Marion Island ◽  
Elephant Seals ◽  
Marine Predator ◽  
Three Dimensional Models

AbstractPhysically weighing large marine mammals sequentially over time has presented researchers with a logistical challenge and has severely limited sample sizes. Using a well-established photogrammetry method we developed a simple mathematical method to calculate accurate mass measurements at specific stages in the life cycle of a top marine predator. Female southern elephant seals (n = 23) at Marion Island were sampled sequentially using photogrammetry and three-dimensional models (based on each photogrammetry project) were built for estimation of body mass. Simple equations were applied to obtain mass at critical instances in their life cycle. Marion Island elephant seal mass data was compared to data obtained from physically weighed elephant seals from King George, South Georgia and Macquarie islands. Females from Marion Island are smaller, but their percentage lactation mass loss is similar to females from these other populations. The similarity of percentage mass loss during lactation between different female populations illustrates the accuracy and practicality of the photogrammetric method over a temporal scale. Photogrammetric mass estimation can be used alongside datasets of physically weighed animals and can greatly benefit ecology and life history studies.

Tag-loss in southern elephant seals, Mirounga leonina, at Marion Island

1997 ◽  
Vol 9 (2) ◽  
pp. 162-167 ◽  
Author(s):  
I.S. Wilkinson ◽  
M.N. Bester
Keyword(s):  
Elephant Seal ◽  
Southern Elephant Seal ◽  
Island Population ◽  
Marion Island ◽  
Mirounga Leonina ◽  
Elephant Seals ◽  
Tag Loss ◽  
Southern Elephant Seals ◽  
Marking Technique ◽  
Loss Rates

Rates of tag-loss are determined for Dalton Jumbo Rototags applied to the hind flippers of 4343 (2208 males, 2135 females) southern elephant seal (Mirounga leonina) pups at Marion Island over an eight year period from 1983–1990 as part of a demographic study of the species. Loss rates were the lowest recorded to date for this species (range 0.0–9.1%). No significant relationship existed between age and rate of tag-loss, neither was there any sex or year related differences in age-specific tag-loss rates. The low rates of loss highlight the value of tagging as a marking technique, and allow for high levels of confidence in the reliability of the population parameters that are derived from the tagging data collected for the Marion Island population.

scholarly journals Arbovirus of Marine Mammals: a New Alphavirus Isolated from the Elephant Seal Louse, Lepidophthirus macrorhini

2001 ◽  
Vol 75 (9) ◽  
pp. 4103-4109 ◽  
Author(s):  
May La Linn ◽  
Joy Gardner ◽  
David Warrilow ◽  
Grant A. Darnell ◽  
Clive R. McMahon ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Marine Mammals ◽  
Elephant Seal ◽  
Southern Elephant Seal ◽  
Mirounga Leonina ◽  
Serological Evidence ◽  
Elephant Seals ◽  
Macquarie Island ◽  
Southern Elephant Seals ◽  
Virus Sequence

ABSTRACT A novel alphavirus was isolated from the louse Lepidophthirus macrorhini, collected from southern elephant seals,Mirounga leonina, on Macquarie Island, Australia. The virus displayed classic alphavirus ultrastructure and appeared to be serologically different from known Australasian alphaviruses. Nearly all Macquarie Island elephant seals tested had neutralizing antibodies against the virus, but no virus-associated pathology has been identified. Antarctic Division personnel who have worked extensively with elephant seals showed no serological evidence of exposure to the virus. Sequence analysis illustrated that the southern elephant seal (SES) virus segregates with the Semliki Forest group of Australasian alphaviruses. Phylogenetic analysis of known alphaviruses suggests that alphaviruses might be grouped according to their enzootic vertebrate host class. The SES virus represents the first arbovirus of marine mammals and illustrates that alphaviruses can inhabit Antarctica and that alphaviruses can be transmitted by lice.

Dynamic age-distributions in a declining population of southern elephant seals

1999 ◽  
Vol 11 (4) ◽  
pp. 445-450 ◽  
Author(s):  
P.A. Pistorius ◽  
M.N. Bester ◽  
S.P. Kirkman
Keyword(s):  
Total Population ◽  
Conversion Factor ◽  
Elephant Seal ◽  
Southern Elephant Seal ◽  
Marion Island ◽  
Elephant Seals ◽  
Breeding Sites ◽  
Seal Population ◽  
Southern Elephant Seals ◽  
The Indian Ocean

Estimates of births and standing age-distributions were combined to estimate the size of the southern elephant seal population at Marion Island at various times during its decline. To estimate births each year from 1986 through 1997 we used the number of adult females hauled out on 15 October, which is the peak haulout date for breeding elephant seal females at all breeding sites in the Indian Ocean. A conversion factor (3.15) was derived from the standing age-distributions, and applied to estimates of annual births to yield total population size. The population at Marion Island declined 37.5% overall from 1986–97 at an annual rate of 4.3% from 1986–91 and c. 2.5% yr−1 afterwards.

scholarly journals Breeding Colony Dynamics of Southern Elephant Seals at Patelnia Point, King George Island, Antarctica

2020 ◽  
Vol 12 (18) ◽  
pp. 2964
Author(s):  
Katarzyna Fudala ◽  
Robert Józef Bialik
Keyword(s):  
Statistical Tests ◽  
Ground Level ◽  
Elephant Seal ◽  
South Shetland Islands ◽  
Southern Elephant Seal ◽  
King George Island ◽  
Elephant Seals ◽  
Southern Elephant Seals ◽  
Physical Barriers ◽  
Population Counts

During the 2019 breeding season (October-December), a battery-powered DIJ Inspire 2 drone was used to investigate a breeding southern elephant seal colony located at Patelnia Point (ASPA 128, King George Island, South Shetland Islands, maritime Antarctica). Twelve unmanned aerial vehicle (UAV) missions conducted 50–70 m above ground level (AGL) were completed to monitor the breeding ground with a maximum of 0.348 km2. The missions were planned in Pix4D Capture software. A drone, with the support of ground cameras and observations, was used to derive population counts, map harems, and track the phenology of the southern elephant seals. Based on data obtained from the UAV missions, orthophotomaps were created in PIX4D Mapper and then analyzed in QGIS. Calculated values of body size parameters such as body length and orthogonal body surface area were used to determine the age and sex of individuals. Analysis of the ranges of the harems on particular days, supported by an analysis of land conditions that generate physical barriers to the movement of animals, allowed zones in which the transformations of groups of harems took place to be determined. The hypothesized hermeticity of the designated zones was supported by statistical tests. The use of drones allows for comprehensive population analyses of the breeding colonies of elephant seals such as censuses of pups and adult individuals, determination of the sex ratio, and spatial analysis of the distribution of breeding formations. In addition, it allows for a more accurate result than ground counting.

Leucistic southern elephant seal at Marion Island?

Polar Biology ◽  
2007 ◽  
Vol 31 (2) ◽  
pp. 255-257 ◽  
Author(s):  
Marthán N. Bester ◽  
Hendrik de Clercq ◽  
G. J. Greg Hofmeyr ◽  
P. J. Nico de Bruyn
Keyword(s):  
Elephant Seal ◽  
Southern Elephant Seal ◽  
Marion Island

The skin and hair of the southern elephant seal, Mirounga leonina (Linn.) I. The facial vibrissae

1966 ◽  
Vol 14 (5) ◽  
pp. 855 ◽  
Author(s):  
JK Ling
Keyword(s):  
Elephant Seal ◽  
Sensory Function ◽  
Southern Elephant Seal ◽  
Sweat Glands ◽  
Mirounga Leonina ◽  
Sebaceous Glands ◽  
Elephant Seals

The arrangement, number, and anatomy of the facial vibrissa follicles of the southern elephant seal, Mirounga leonina (Linn.), are described. There are three groups of vibrissae: mystacial, supraorbital, and rhinal, containing approximately 38, 7, and 1 follicles, respectively. These specialized hairs appear to be retained for at least 2 yr and are not shed with the pelage hairs at each annual moult. The histology of the vibrissa follicles and associated organs is described and discussed in relation to their sensory function. Vibrissa follicles of elephant seals are different in anatomy from those described in the mouse and rat: the ringwulst is relatively smaller and, in addition to the sebaceous glands, there are tubular glands of unidentified function but resembling apocrine sweat glands.

scholarly journals Integrative modelling of animal movement: incorporating in situ habitat and behavioural information for a migratory marine predator

2013 ◽  
Vol 280 (1750) ◽  
pp. 20122262 ◽  
Author(s):  
Sophie Bestley ◽  
Ian D. Jonsen ◽  
Mark A. Hindell ◽  
Christophe Guinet ◽  
Jean-Benoît Charrassin
Keyword(s):  
Process Model ◽  
Animal Movement ◽  
Elephant Seal ◽  
Southern Elephant Seal ◽  
Model Parameters ◽  
Mirounga Leonina ◽  
Marine Predator ◽  
Fundamental Goal ◽  
First Time

A fundamental goal in animal ecology is to quantify how environmental (and other) factors influence individual movement, as this is key to understanding responsiveness of populations to future change. However, quantitative interpretation of individual-based telemetry data is hampered by the complexity of, and error within, these multi-dimensional data. Here, we present an integrative hierarchical Bayesian state-space modelling approach where, for the first time, the mechanistic process model for the movement state of animals directly incorporates both environmental and other behavioural information, and observation and process model parameters are estimated within a single model. When applied to a migratory marine predator, the southern elephant seal ( Mirounga leonina ), we find the switch from directed to resident movement state was associated with colder water temperatures, relatively short dive bottom time and rapid descent rates. The approach presented here can have widespread utility for quantifying movement–behaviour (diving or other)–environment relationships across species and systems.

Physiological implications of continuous, prolonged, and deep dives of the southern elephant seal (Mirounga leonina)

1992 ◽  
Vol 70 (2) ◽  
pp. 370-379 ◽  
Author(s):  
Mark A. Hindell ◽  
David J. Slip ◽  
Harry R. Burton ◽  
Michael M. Bryden
Keyword(s):  
Resting Metabolic Rate ◽  
Elephant Seal ◽  
Southern Elephant Seal ◽  
Adult Males ◽  
Mirounga Leonina ◽  
Physiological Mechanisms ◽  
Elephant Seals ◽  
Aerobic Dive Limit ◽  
Southern Elephant Seals ◽  
Extended Surface

The diving behaviour of 14 adult southern elephant seals was investigated using time depth recorders. Each of the seals performed some dives that were longer than its theoretical aerobic dive limit. Forty-four percent of all dives made by post-moult females exceeded the calculated limit compared with 7% of those made by postbreeding females and less than 1% of those made by adult males. The extended dives displayed characteristics that suggested that they were predominantly foraging dives, although some were apparently rest dives. Dives longer than the calculated aerobic limits often occurred in bouts; the longest consisted of 63 consecutive dives and lasted 2 days. Postmoult females performed longer bouts of extended dives than postbreeding females. Extended surface periods (longer than 30 min) were not related to the occurrence of extended dives or bouts of extended dives. The possible physiological mechanisms that permit such prolonged continuous dives are discussed. Southern elephant seals may increase the aerobic capacity of dives by lowering their metabolism to approximately 40% of the resting metabolic rate on long dives. There is substantial interseal variability in the methods used to cope with long dives. Some animals appear to use physiological strategies that allow them to prolong the time available to them at the bottom of a dive, while others use alternative strategies that may limit the time available at the bottom of their dives.

Branding Elephant Seals for life-history studies

Polar Record ◽  
1967 ◽  
Vol 13 (85) ◽  
pp. 447-449 ◽  
Author(s):  
Susan E. Ingham
Keyword(s):  
Ecological Study ◽  
Individual Recognition ◽  
Elephant Seal ◽  
Southern Elephant Seal ◽  
Mirounga Leonina ◽  
Elephant Seals ◽  
Macquarie Island ◽  
Heard Island ◽  
Antarctic Research

In 1949 the Australian National Antarctic Research Expeditions (ANARE) began a long-term ecological study of the Southern Elephant Seal (Mirounga leonina) at HeardIsland. The biologists devised a method of branding seals for individual recognition (Chittleborough and Ealey, 1953) which has been modified only in detail since then (Carrick and Ingham, 1962a). At Heard Island, pups were branded every year until 1953, but the study here came to an end with the closing of the ANARE station in 1955. At Macquarie Island, pups have been branded every year from 1951 to 1965, giving a sample of individuals of known age and known history.

Marion Island elephant seals: the paucity-of-males hypothesis tested

1999 ◽  
Vol 77 (10) ◽  
pp. 1547-1554 ◽  
Author(s):  
I S Wilkinson ◽  
R J van Aarde
Keyword(s):  
Sexual Activity ◽  
Sex Ratios ◽  
Elephant Seal ◽  
Southern Elephant Seal ◽  
Marion Island ◽  
Mirounga Leonina ◽  
Breeding Sites ◽  
Research Activities ◽  
Mating Opportunities ◽  
The Relationship

The southern elephant seal, Mirounga leonina, population at Marion Island has declined since the start of research activities there in 1973, as have populations at other Indian Ocean breeding sites. One suggested mechanism for the decline at Marion Island is a shortage of males, resulting in low insemination rates. We tested this "paucity-of-males" hypothesis by looking at (i) adult sex ratios, (ii) male sexual activity, and (iii) the relationship between levels of sexual activity and the probability of a cow pupping in the following season. Sex ratios were similar to those at other sites where populations are either stable (South Georgia) or increasing (Peninsula Valdes). Dominant bulls monopolised mating opportunities, achieving 98.1% of 629 observed copulations over three seasons. Of the 138 cows coming ashore, only 4 (2.9%) were not seen mating and 89% copulated with only one bull; dominant bulls copulated with all but 1 of the 134 (99.3%) cows that did mate. Cows were mated more frequently than at sites with stable and increasing populations. There was no difference in the observed level of sexual activity between cows seen pupping in the following season and those who failed to pup. This indicates that bulls monopolising harems are capable of inseminating all the cows. Such findings refute the paucity-of-males hypothesis.

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