EARTH SCIENCE > BIOLOGICAL CLASSIFICATION > ANIMALS/VERTEBRATES > MAMMALS > CARNIVORES > SEALS/SEA LIONS/WALRUSES
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Results from a February 2007 survey of the Vestfold Hills coastline and offshore islands for used and disused southern elephant seal wallows. The data here are point locations of the wallows, not the extents or boundaries of the wallows. The table below gives the coordinates (decimal degrees) for the elephant seal wallows found, their unofficial names and the wallow status as used or disused at the time of survey. Data were used in the 2018 Vestfold Hills/Davis Station Helicopter map: Wallow name Latitude Longitude Status Hawker Island -68.637360 77.840040 Used Hawker Island -68.634950 77.841310 Used Hawker Island -68.632180 77.841560 Used Mule Island -68.647860 77.825900 Unused Mule Island -68.646650 77.823920 Unused Zappert Point -68.505100 78.081020 Unused Old Wallow -68.598345 77.937185 Used Davis beach -68.577926 77.967032 Used Heidemann Bay -68.592067 77.945325 Used North of station -68.571916 77.971011 Used
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This is a digital version of the grid reference map used to plot all sightings of Weddell seals in the Vestfold Hills. The point of origin is the same as the original map and each grid cell is numbered with the same numbering scheme. This can be used to plot any data using the same numbering scheme by joining (ArcInfo) or linking (ArcView) records to this coverage's polygon attribute table (pat) through the item GRIDREF. The original map was a 1:100 000 map of the Vestfolds, provided by Harry Burton, with a grid drawn over it. The grid references were given as either six or four figure values on which field scientists are to plot their data. This map has the following Antarctic Division drawing reference number: M/75/05A Some research with John Cox revealed that this grid was drawn up over a map digitised from another map with the following specifications: Scale 1: 100 000 Date: 1958 (reprinted 1972) Projection: Polyconic Published by: Division of National Mapping, Canberra Reference number: NMP/58/084 Data are referenced to a 'grid' of 1 minute spacing in x axis and 30 second spacing in y axis. The point of origin is apparently 68 20 S 77 48 E. There are 45 rows and 47 columns. The 'grid reference' is in fact in geographic coordinates (but using arbitrary units) so the projection of the original map became irrelevant. The procedure adopted to create a new digital grid was as follows: (Carried out in Arc/Info) 1. Generate a coverage using the original 'grid references'. 2. Tics were also generated using the corners of the 'grid reference' system. 3. A new coverage was created with tics at the same locations but given the true latitude/longitude vales. 4. The original coverage was then transformed to the new coverage based on the new tic values. 5. The new coverage was then projected from geographic coordinates to UTM metres. The data locations were then viewed in Arc/Info using a coverage of the coastline supplied by the Mapping Officer, Antarctic Division. This had previously been determined to be in the UTM projection. An offset was clearly visible between the data locations and the coastline. In order to determine whether the offset was more or less uniform, ten locations were plotted from the original data onto the original map using the 'grid'. Finally a manual corrected was made by moving all the data locations by a uniform distance of 508 metres north and 68 metres west. Information from John van den Hoff, February 2019: The grid cells were originally labelled from 1 to 47 along the x axis and 1 to 45 along the y axis. The four digit values in the GRIDREF field of the attribute table are the x value followed by the y value. To avoid confusion between x and y values, the grid was later revised so that the y values were prefixed with a ‘1’ so for example 01 became 101. The GRIDREF_X and GRIDREF_Y fields have the x and y values of the revised grid. This needs to be kept in mind when data is sourced from field books. The map shows the revised grid.
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Some mammalian and avian species alter their vocal communication signals to reduce masking by background noises (including conspecific calls). A preliminary study suggested that Weddell seals (Leptonychotes weddellii) increase the durations of some underwater call types when overlapped by another calling seal. The present study examined the durations and overlapping sequences of Weddell seal calls recorded in Eastern Antarctica. The calling rate, call type (13 major categories), total duration, numbers of elements per call, and overlapping order of 100-200 consecutive calls per recording location were measured. In response to increased conspecific calling rates, the call durations and numbers of elements (within repeated-element call types) did not change or became shorter. Calls that were not overlapped were 3.8 plus or minus 6.1 s long, the first call in a series of overlapped calls was 14.4 plus or minus 15.7 s and subsequent calls in an overlapping series were 6.5 plus or minus 10.3 s. The mean durations of non-overlapped and overlapped calls matched random distributions. Weddell seals do not appear to be adjusting the durations or timing of their calls to purposefully avoid masking each others' calls. The longer a call is, the more likely it is to overlap another call by chance. An implication of this is that Weddell seals may not have the behavioural flexibility to reduce masking by altering the temporal aspects of their calls or calling behaviours as background noises (natural and from shipping) increase.
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This database is a compendium of histories of known age seals (leopard) from observations across the Southern Ocean but primarily focussed on Macquarie Island. Although the following information pertains to Elephant Seals, it is assumed similar procedures were undertaken with the Leopard Seals between 1957 and 1999: "At Macquarie Island 1000 seals were weighed per annum between 1993-2003 at birth and individually marked with two plastic flipper tags in the inter-digital webbing of their hind flippers. These tagged seals were weighed again at weaning, when length, girth, fat depth, and flipper measurements were made. Three weeks after weaning 2000 seals were permanently and individually marked by hot-iron branding. Recaptures and re-weighings of these known aged individuals were used to calculate growth and age-specific survival of the seals. Similar data were collected from elephant seals between 1950 and 1965 when seals were individually marked by hot-iron branding. Mark-recapture data from these cohorts were used to assess the demography of the declining population. Length and mass data were also collected for these cohorts and were used, for the first time, to assess the growth of individual seals without killing them." The database was held by the Australian Antarctic Data Centre, but was taken offline due to maintenance problems. A snapshot of the database was taken in June 2018 and stored in an access database. This work was completed as part of ASAC project 90.
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This log contains notes and observations of Weddell seals at Mawson, collected between 1979 and 1991. The hard copy of the log has been archived by the Australian Antarctic Division library.
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This database is a compendium of histories of known age seals (Weddell) from observations across the Southern Ocean but focussed on the Windmill Islands, Mawson and the Vestfold Hills. Although the following information pertains to Elephant Seals, it is assumed similar procedures were undertaken with the Weddell Seals between 1973 and 2006: At Macquarie Island 1000 seals were weighed per annum between 1993-2003 at birth and individually marked with two plastic flipper tags in the inter-digital webbing of their hind flippers. These tagged seals were weighed again at weaning, when length, girth, fat depth, and flipper measurements were made. Three weeks after weaning 2000 seals were permanently and individually marked by hot-iron branding. Recaptures and re-weighings of these known aged individuals were used to calculate growth and age-specific survival of the seals. Similar data were collected from elephant seals between 1950 and 1965 when seals were individually marked by hot-iron branding. Mark-recapture data from these cohorts were used to assess the demography of the declining population. Length and mass data were also collected for these cohorts and were used, for the first time, to assess the growth of individual seals without killing them. The database was held by the Australian Antarctic Data Centre, but was taken offline due to maintenance problems. A snapshot of the database was taken in June 2018 and stored in an access database. This work was completed as part of ASAC project 90.
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This file contains a log of biological observations of Weddell Seals and Leopard Seals taken at Mawson Station between 1974 and 1979. The hard copy of the log has been archived by the Australian Antarctic Division library.
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Despite being a ubiquitous and abundant component of the Southern Ocean ecosystem, pack-ice seals (crabeater, Ross and leopard seals) are notoriously difficult to census as they are sparsely distributed over large regions of remote pack-ice. Historically, population censuses have been made from ship- or helicopter-based surveys, which are expensive and logistically difficult, and this inevitably leads to data which are limited, in time and space. High resolution images allow us now to accurately census seals e.g. elephant and Weddell seals at unprecedented spatial and temporal scales. Using this technology promises to provide regular estimates of the numbers of pack-ice seals in important regions such as Prydz Bay This study will develop techniques to survey pack-ice seals from high resolution satellite images, including automatic detection functions and a preliminary habitat model based on the characteristics of the ice contained in the images.
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This is a scanned copy of the annual report on vertebrate biology at Macquarie Island, 1990, by Rupert Woods. The scanned report contains information on: - Elephant seal census - Elephant seal tagging program (1984-1985, 1987-1991) - Freeze branding - Weaner weights - Anaesthetics - Gastric lavage - Opthalmology problems - Penguin crush (mass deaths of King Penguins) - PTTs and TDTRs - Toxoplasmosis - Morbilivirus - DNA samples (elephant seals and fur seals) - Anaesthesia and surgery of birds - Details of a neo-natal longfinned pilot whale washed ashore - Fur seals (census, euthanasia, injuries, net entanglements) - Letters - Abandoned elephant seal pup - Drift cards - Killer whale attack
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This is a scanned copy of the vertebrate ecologists report from Macquarie Island, 1985, written by Mark Hindell. The report includes: The diet of the four penguin species breeding on Macquarie Island (Royal, Rockhopper, King and Gentoo). Aspects of the morphology of the four penguin species The past and present status of the southern elephant seal on Macquarie and Heard Islands