Satellite Tracker Deployments On Adult, Male Australian Fur Seals (Arctophalus Pusillus Doriferus): Methods And Preliminary Results

2002 ◽  
Vol 24 (1) ◽  
pp. 73 ◽  
Author(s):  
R Kirkwood ◽  
N Gales ◽  
M Lynch ◽  
P Dann
Keyword(s):  
Adult Male ◽  
Early Spring ◽  
Preliminary Results ◽  
Fur Seals ◽  
Satellite Transmitters ◽  
Rest Sites ◽  
Water Depths

In May 1999, four adult male, Australian fur seals (Arctocephalus pusillus doriferus) from the Seal Rocks colony, Victoria, were fitted with satellite transmitters that provided locations for between 2 and 7 months. Foraging trips during winter and early spring averaged 7.4 days (range for all trips 0.9 to 24.6) and between-trip rests lasted 2.8 days (range 0.3 to 5.7). Between-trip rest sites included Seal Rocks, other colonies and other haul-out sites. The seals foraged mostly in western Bass Strait and in water depths < 100 m.

At-sea movements and habitat use of adult male Australian fur seals (Arctocephalus pusillus doriferus)

2006 ◽  
Vol 84 (12) ◽  
pp. 1781-1788 ◽  
Author(s):  
Roger Kirkwood ◽  
Michael Lynch ◽  
Nick Gales ◽  
Peter Dann ◽  
Michael Sumner
Keyword(s):  
Habitat Use ◽  
Continental Shelf ◽  
Adult Male ◽  
Maximum Distance ◽  
Commercial Fisheries ◽  
Southeastern Australia ◽  
Foraging Area ◽  
Fur Seals ◽  
Water Columns ◽  
Foraging Ranges

Foraging by adult male otariids, a demographic component that often interacts with commercial fisheries, are poorly known. To assess movement patterns and habitat use, nine adult male Australian fur seals ( Arctocephalus pusillus doriferus Wood Jones, 1925) from Seal Rocks, in northern Bass Strait, southeastern Australia, were tracked for periods ranging from 66 to 223 d during 1999–2001. Mean ± SD at-sea and on-land durations were 6.9 ± 2.1 d (range 2.3–10.3 d, n = 9 seals) and 2.4 ± 0.9 d (range 0.8–4.1 d), respectively. All seals foraged almost exclusively in continental shelf waters and mostly (65%–97% of time at sea) in water columns that were between 40 and 100 m deep. Six of nine seals tracked for >30 d spent 64%–98% of their time-at-sea foraging at distances <200 km from Seal Rocks, although the maximum distance achieved from the colony was 1208 km. The seals’ foraging ranges overlapped with the ranges of operation of virtually all fin-fish fisheries in southeastern Australia, but fisheries overlap was low in the most frequented foraging area of central-western Bass Strait.

scholarly journals Mass Mortality of Adult Male Subantarctic Fur Seals: Are Alien Mice the Culprits?

PLoS ONE ◽  
2008 ◽  
Vol 3 (11) ◽  
pp. e3757 ◽  
Author(s):  
P. J. Nico de Bruyn ◽  
Armanda D. S. Bastos ◽  
Candice Eadie ◽  
Cheryl A. Tosh ◽  
Marthán N. Bester
Keyword(s):  
Adult Male ◽  
Mass Mortality ◽  
Fur Seals ◽  
Subantarctic Fur Seals

scholarly journals Winter distribution of juvenile and sub-adult male Antarctic fur seals (Arctocephalus gazella) along the western Antarctic Peninsula

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
David March ◽  
Massimiliano Drago ◽  
Manel Gazo ◽  
Mariluz Parga ◽  
Diego Rita ◽  
...  
Keyword(s):  
Antarctic Peninsula ◽  
Adult Male ◽  
Antarctic Krill ◽  
South Shetland Islands ◽  
Distribution Area ◽  
Arctocephalus Gazella ◽  
Western Antarctic Peninsula ◽  
Adult Males ◽  
Fur Seals ◽  
Antarctic Fur Seals

AbstractDetailed knowledge of habitat use by marine megafauna is critical to understand their ecological roles and for the adequate management of marine resources. Antarctic fur seals (Arctocephalus gazella) inhabiting the Atlantic sector of the Southern Ocean prey largely on Antarctic krill (Euphausia superba) and play a central role in managing the krill fishery. Here, we assessed the demographic structure of three post-mating, early moult male haul-outs in the South Shetland Islands in early March and calculated the relative contribution of juveniles (1–4 years old) and sub-adult males (5–6 years) to the population remaining in maritime Antarctica after the breeding season. We also satellite tagged 11 juvenile males and four sub-adult males to analyze their movements and develop a species distribution model including both age classes. Our results highlighted the dominance of young individuals in the male population, revealed that they do not behave as central place foragers and identified key environmental drivers that affected their distribution at-sea throughout winter. Predicted potential foraging habitat overlapped highly with the known distribution of Antarctic krill, and identified the waters off the western Antarctic Peninsula and the Scotia Sea as the core of the distribution area of juvenile and sub-adult male Antarctic fur seals in winter. This pattern is similar to that of adult males but totally different from that of adult females, as the latter overwinter in areas at latitude 45–55° S. This segregation has implications for the ecology and management of the krill fishery.

At-Sea Movements Of Female Australian Fur Seals Arctocephalus Pusillus Doriferus

2002 ◽  
Vol 24 (1) ◽  
pp. 65 ◽  
Author(s):  
CL Littnan ◽  
JPY Arnould
Keyword(s):  
Small Area ◽  
Fishing Effort ◽  
Commercial Fishing ◽  
Middle Phase ◽  
Average Speed ◽  
The Third ◽  
Foraging Area ◽  
Fur Seals ◽  
Satellite Transmitters ◽  
The Mean

In May 1999, satellite transmitters were deployed on three lactating female Australian fur seals (Arctocephalus pusillus doriferus) at Kanowna Island (39� 10' S, 146� 18' E) and at-sea movements were recorded for 65 ? 174 days. The mean foraging trip and on-shore durations (8 and 2 days, respectively) were not significantly different to that previously reported for the species. The seals all foraged in three separate areas of Bass Strait with each individual repeatedly returning to the same general location. Movements during foraging trips fell into two distinct patterns. In one pattern, displayed by two individuals, the females travelled directly to a presumed foraging area. In this trip type, outward and return travel consisted of relatively constant headings at moderate speed (1.37 � 0.07 m/s) while the middle phase was characterised by repeated changes in direction within a small area and significantly lower speeds (0.82 � 0.07 m/s). The second pattern, displayed by the third individual, consisted of a looping path with relatively uniform average speed (1.14 � 0.06 m/s) throughout the trip. The three foraging areas were: 1) inshore area between Wilsons Promontory and Lakes Entrance; 2) offshore in proximity to The Skerries; and 3) up to 200 km south of Wilsons Promontory in central Bass Strait. The foraging areas used by these seals overlap with regions of commercial fishing effort raising the potential for some conflict.

Movements and swimming speed of narwhals, Monodon monoceros, equipped with satellite transmitters in Melville Bay, northwest Greenland

1995 ◽  
Vol 73 (11) ◽  
pp. 2106-2119 ◽  
Author(s):  
R. Dietz ◽  
M. P. Heide-Jørgensen
Keyword(s):  
Swimming Speed ◽  
Open Water ◽  
Time Span ◽  
Wildlife Sanctuary ◽  
Monodon Monoceros ◽  
Radio Transmitters ◽  
Satellite Transmitters ◽  
The Mean ◽  
Related Pattern ◽  
Water Depths

Positions were obtained for up to 100 days from nine narwhals, Monodon monoceros, representing both sexes and all age categories instrumented with satellite-linked UHF radio transmitters in Melville Bay (76°03′06″N, 61°14′90″W), northwest Greenland, in August – September 1993 and 1994. In both years all nine narwhals stayed within Melville Bay during the open-water portion of the tracking period. Most of the coastal positions obtained were inside the Melville Bay Wildlife Sanctuary. The narwhals also moved up to 100 km offshore to areas where water depths exceed 1000 m. There was no discernible relationship between tide and the movements of whales. By early to mid-October, the narwhals left Melville Bay and started migrating southwards along the continental slope, where water depths range from 500 to 1000 m. This southward movement ceased some 700 km farther south in late November, still in water with depths of 500–1000 m. The mean swimming speed of the whales during September varied between 2.9 and 8.2 km/h, calculated for intervals of 0.5–5 h between consecutive positions. No size- or sex-related pattern could be detected in swimming speeds, nor could any diurnal differences be found. The use of longer intervals between consecutive positions resulted in significantly lower calculated swimming speeds, suggesting that swimming speed will be underestimated if calculated over a longer time span. The mean swimming speed of one subadult and one adult male decreased significantly from 5.5 and 5.8 km/h in September to 2.7 km/h in November.

The Effect of Thermoregulatory Behaviour On the Mating System of the Juan Fernández Fur Seal, Arctocephalus Philippii

Behaviour ◽  
1991 ◽  
Vol 119 (1-2) ◽  
pp. 104-126 ◽  
Author(s):  
Daryl J. Boness ◽  
John M. Francis
Keyword(s):  
Solar Radiation ◽  
Social Behaviour ◽  
Cold Water ◽  
Mating Strategies ◽  
Male Mating ◽  
Fur Seals ◽  
Behavioural Strategy ◽  
Male Mating Strategies ◽  
Fur Seal ◽  
Rest Sites

AbstractRecent studies of fur seals and sea lions (Otariids) which are cold water adapted, indicate that social behaviour in hotter climes is constrained by the form and availability of cool substrate provided by the rookery environment. This first study of the behaviour of the Juan Fernández fur seal provides new evidence of this relationship and the extent to which thermoregultory requirements can affect social behaviour in pinnipeds. Females of this species on Alejandro Selkirk Island made daily movements from inland pupping and rest sites to the shoreline and into the water in response to rapid increases in solar radiation to levels exceeding 1.3 cal/cm2/min. Thirty percent of these females floated and groomed offshore in the afternoon in areas protected from the surf by offshore islets and rocky reefs. Males held territories on land either along the shoreline (39%) or in land-locked areas (45%) as is typical of fur seals, or held completely aquatic territories (16%) that encompassed the site where females floated. The average aquatic male, present on territory primarily during the afternoon hours when females floated offshore, achieved as many copulations as did the average land-locked or shoreline male. Land-locked males often abandoned their territories for short periods (45 minutes on average) in response to increasing solar radiation in the afternoon and at a time when female numbers on land were low. The existence of aquatic territoriality as a successful mating strategy has not yet been documented for any other otariid. The occurrence of this behavioural strategy is likely a product of the interaction of thermoregulatory constraints and topographical features which together promote predictable aggregations of females offshore. This study further substantiates that constraints on female aggregation appear to dictate the range and mode of male mating strategies in otariids.

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