scholarly journals Islands in the sea: extreme female natal site fidelity in the Australian sea lion, Neophoca cinerea

2007 ◽  
Vol 4 (1) ◽  
pp. 139-142 ◽  
Author(s):  
R.A Campbell ◽  
N.J Gales ◽  
G.M Lento ◽  
C.S Baker
Keyword(s):  
Site Fidelity ◽  
Population Subdivision ◽  
Sea Lion ◽  
Sea Lions ◽  
Neophoca Cinerea ◽  
Australian Sea Lion ◽  
Fur Seals ◽  
Geographical Distances ◽  
High Level ◽  
Fixed Population

Pinnipeds (seals, fur seals, sea lions and walrus) form large breeding aggregations with females often remaining faithful to a natal site or area. In these cases, females are philopatric to regional areas on broad geographical scales of hundreds to thousands of kilometres. An investigation of variation in a control region sequence of mtDNA in the Australian sea lion ( Neophoca cinerea ) has shown a case of extreme female natal site fidelity that has resulted in almost fixed population differentiation across its range ( Φ ST =0.93). This high level of population subdivision over short geographical distances (approx. 60 km) is unparalleled in any social marine mammal and reflects the unique life-history traits of this rare species. The high level of population subdivision and exclusive female natal site fidelity has important ramifications for conservation management, and poses many interesting questions of both academic and applied interest.

Stautus of the Australian sea lion, Neophoca cinerea, in the Great Australian Bight

1996 ◽  
Vol 23 (6) ◽  
pp. 741 ◽  
Author(s):  
TE Dennis ◽  
PD Shaughnessy
Keyword(s):  
Total Population ◽  
South Australia ◽  
Previous Estimate ◽  
Sea Lion ◽  
Breeding Sites ◽  
Sea Lions ◽  
Neophoca Cinerea ◽  
Australian Sea Lion ◽  
Fur Seals ◽  
Great Australian Bight

In August 1994, a systematic survey of potential haulout sites of the Australian sea lion, Neophoca cinerea, was conducted along the coastline of the Great Australian Bight from Twin Rocks to Wilson Bluff, a distance of 206 km. A total of 289 Australian sea lions was recorded at 23 sites widely dispersed at the base of the Bunda Cliffs, hauled out on perched platforms formed by collapsed sections of cliff at various levels above the sea. Of these, 37 sea lions were recorded in a deep cave accessed from the sea. The total included 86 pups aged under 12 months, which were probably born in the region; six of these had almost completed moulting their natal pelage and were estimated to be near four months old. Only 12 New Zealand fur seals, Arctocephalus forsteri, were recorded. The Australian sea lion sites located in 1994 were surveyed again in August-September 1995, during a predicted breeding season. In this survey, a total of 284 sea lions was recorded at nine sites in South Australia and one site in Western Australia. This included 90 pups under six months of age, of which 44 were still in lanugo. Overall, we recorded 10 breeding sites and 14 haulout sites. Breeding events were recorded at one colony over three seasons and were consistent with an 18-month cycle. By extrapolating from the number of sea lion pups found in 1994, the population for the Great Australian Bight region in South Australia is estimated to be 613-774. This addition increases the previous estimate for South Australia by 9.3% and the previous total population estimate by 6.6%.

Louse infestations of the Australian sea lion Neophoca cinerea.

2007 ◽  
Vol 29 (1) ◽  
pp. 103 ◽  
Author(s):  
R.R. McIntosh ◽  
M.D. Murray
Keyword(s):  
Sea Lion ◽  
Sea Lions ◽  
Neophoca Cinerea ◽  
Australian Sea Lion

Sea lions (Neophoca cinerea) at several South Australian islands were infested with the anopluran louse Antarctophthirus microchir.

scholarly journals Colony Location and Captivity Influence the Gut Microbial Community Composition of the Australian Sea Lion (Neophoca cinerea)

2016 ◽  
Vol 82 (12) ◽  
pp. 3440-3449 ◽  
Author(s):  
Tiffany C. Delport ◽  
Michelle L. Power ◽  
Robert G. Harcourt ◽  
Koa N. Webster ◽  
Sasha G. Tetu
Keyword(s):  
Microbial Community ◽  
Marine Mammals ◽  
Animal Health ◽  
Sea Lion ◽  
Content Type ◽  
Sea Lions ◽  
Neophoca Cinerea ◽  
Australian Sea Lion ◽  
Captive Populations ◽  
Gut Microbial Community

ABSTRACTGut microbiota play an important role in maintenance of mammalian metabolism and immune system regulation, and disturbances to this community can have adverse impacts on animal health. To better understand the composition of gut microbiota in marine mammals, fecal bacterial communities of the Australian sea lion (Neophoca cinerea), an endangered pinniped with localized distribution, were examined. A comparison of samples from individuals across 11 wild colonies in South and Western Australia and three Australian captive populations showed five dominant bacterial phyla:Firmicutes,Proteobacteria,Bacteroidetes,Actinobacteria, andFusobacteria. The phylumFirmicuteswas dominant in both wild (76.4% ± 4.73%) and captive animals (61.4% ± 10.8%), whileProteobacteriacontributed more to captive (29.3% ± 11.5%) than to wild (10.6% ± 3.43%) fecal communities. Qualitative differences were observed between fecal communities from wild and captive animals based on principal-coordinate analysis. SIMPER (similarity percentage procedure) analyses indicated that operational taxonomic units (OTU) from the bacterial familiesClostridiaceaeandRuminococcaceaewere more abundant in wild than in captive animals and contributed most to the average dissimilarity between groups (SIMPER contributions of 19.1% and 10.9%, respectively). Differences in the biological environment, the foraging site fidelity, and anthropogenic impacts may provide various opportunities for unique microbial establishment in Australian sea lions. As anthropogenic disturbances to marine mammals are likely to increase, understanding the potential for such disturbances to impact microbial community compositions and subsequently affect animal health will be beneficial for management of these vulnerable species.IMPORTANCEThe Australian sea lion is an endangered species for which there is currently little information regarding disease and microbial ecology. In this work, we present an in-depth study of the fecal microbiota of a large number of Australian sea lions from geographically diverse wild and captive populations. Colony location and captivity were found to influence the gut microbial community compositions of these animals. Our findings significantly extend the baseline knowledge of marine mammal gut microbiome composition and variability.

Milk composition of Australian sea lions, Neophoca cinerea: variability in lipid content

1991 ◽  
Vol 69 (10) ◽  
pp. 2556-2561 ◽  
Author(s):  
Maria B. Kretzmann ◽  
Daniel P. Costa ◽  
Lesley V. Higgins ◽  
D. J. Needham
Keyword(s):  
Lipid Content ◽  
Milk Fat ◽  
Milk Composition ◽  
Fat Content ◽  
Sea Lion ◽  
Sea Lions ◽  
Milk Samples ◽  
Stage Of Lactation ◽  
Neophoca Cinerea ◽  
Australian Sea Lion

Thirty-eight milk samples collected over three seasons from 23 individual Australian sea lions (Neophoca cinerea) were analyzed. Mean milk composition was 25.4% lipid (± 9.3% SD), 62.4% water (± 8.1%), 10.5% protein (± 2.2%), and 0.9% ash (± 0.2%). Milk composition appeared to vary considerably among females, and occasionally between successive samples from the same individual. Milk fat content was not correlated with pup age (stage of lactation), female mass, length of the preceding foraging trip, or time onshore prior to milk collection. The relatively low lipid content of Australian sea lion milk compared with that of some other otariid seals is consistent with the hypothesis that otariid females making relatively short trips to sea produce milk with lower fat content than those species which make foraging trips of longer duration.

Rate of passage of digesta through the alimentary tract of the New Zealand fur seal (Arctocephalus forsteri) and the Australian sea lion (Neophoca cinerea) (Carnivora : Otariidae)

1999 ◽  
Vol 47 (2) ◽  
pp. 193 ◽  
Author(s):  
B. Bodley ◽  
the late J. R. Mercer ◽  
M. M. Bryden
Keyword(s):  
New Zealand ◽  
Feeding Time ◽  
Sea Lions ◽  
First Feeding ◽  
Neophoca Cinerea ◽  
Australian Sea Lion ◽  
Fur Seals ◽  
The Mean ◽  
Initial Recovery ◽  
New Zealand Fur Seal

The inert marker titanium dioxide was added to the food of two male New Zealand fur seals (Arctocephalus forsteri) and three Australian sea lions (Neophoca cinerea) in Taronga Zoo, Sydney, in a series of 15 trials. The enclosures were checked constantly during daylight hours, and defaecation times and location of samples noted. Samples were collected at feeding times, at approximately 0930, 1300 and 1500 hours. During the night the animals were checked at 30-min intervals, the location of samples noted, and samples collected at the first feeding time next morning. Faecal collections were made for up to 50 h after dosing. Marker concentrations in faecal dry matter were determined and mean retention times calculated from the mean concentration-time curves. The mean time between dosing and first recovery of marker (Initial Recovery Time) was 4 h for A. forsteri and 6.5 h for N. cinerea. Mean retention time, a better index of rate of passage of digesta, was 14.6 h for A. forsteri and 14.9 h for N. cinerea. Thus, the marker concentration curves indicated a rapid rate of food transit through the gastrointestinal tract, as has been observed in several (but not all) pinniped species.

Dietary analysis of regurgitates and stomach samples from free-living Australian sea lions

2006 ◽  
Vol 33 (8) ◽  
pp. 661 ◽  
Author(s):  
Rebecca R. McIntosh ◽  
Brad Page ◽  
Simon D. Goldsworthy
Keyword(s):  
Prey Species ◽  
South Australia ◽  
Rock Lobster ◽  
Sea Lion ◽  
Free Living ◽  
Dietary Analysis ◽  
Sea Lions ◽  
Neophoca Cinerea ◽  
Australian Sea Lion ◽  
Sepia Apama

Dietary remains recovered from Australian sea lion (Neophoca cinerea) digestive tracts and regurgitate samples from Seal Bay (Kangaroo Island, South Australia) were used to identify prey species consumed. Four of eight digestive tracts collected (50%) contained prey items located only in the stomach. On the basis of biomass reconstruction of cephalopod prey remains, octopus contributed 40% of the biomass in the samples, giant cuttlefish (Sepia apama) contributed 30% and ommastrephid squids contributed 14% biomass. The remains of several fish species were found in the samples: leatherjacket (Monocanthidae), flathead (Platycephalus sp.), swallowtail (Centroberyx lineatus), common bullseye (Pempheris multiradiata), southern school whiting (Sillago flindersi) and yellowtail mackerel (Trachurus novaezelandiae). Southern rock lobster (Jasus edwardsii) and swimming crab (Ovalipes australiensis) carapace fragments, little penguin (Eudyptula minor) feathers and bones and shark egg cases (oviparous species and Scyliorhinidae sp.) were also identified.

Assessing the use of milk fatty acids to infer the diet of the Australian sea lion (Neophoca cinerea)

2009 ◽  
Vol 36 (2) ◽  
pp. 169 ◽  
Author(s):  
A. M. M. Baylis ◽  
D. J. Hamer ◽  
P. D. Nichols
Keyword(s):  
South Australia ◽  
Satellite Tracking ◽  
Sea Lion ◽  
Milk Fatty Acids ◽  
Sea Lions ◽  
Neophoca Cinerea ◽  
Australian Sea Lion ◽  
Fa Composition ◽  
Pinniped Species ◽  
Management Plans

Information on the diet of threatened species is important in devising appropriate management plans to ensure their conservation. The Australian sea lion (Neophoca cinerea) is Australia’s only endemic and globally one of the least numerous pinniped species. However, dietary information is currently limited because of the difficulty in using traditional methods (identification of prey hard parts from scats, regurgitates and stomach samples) to reliably provide dietary information. The present study assessed the use of fatty acid (FA) analysis to infer diet using milk samples collected from 11 satellite tracked Australian sea lions from Olive Island, South Australia. Satellite tracking revealed that females foraged in two distinct regions; ‘inshore’ regions characterised by shallow bathymetry (10.7 ± 4.8 m) and ‘offshore’ regions characterised by comparatively deep bathymetry (60.5 ± 13.4 m). Milk FA analysis indicated significant differences in the FA composition between females that foraged inshore compared with those that foraged offshore. The greatest differences in relative levels of individual FAs between the inshore and offshore groups were for 22 : 6n-3 (6.5 ± 1.2% compared with 16.5 ± 1.9% respectively), 20 : 4n-6 (6.1 ± 0.7 compared with 2.5 ± 0.7 respectively) and 22 : 4n-6 (2.4 ± 0.2% compared with 0.8 ± 0.2% respectively). Using discriminant scores, crustacean, cephalopod, fish and shark-dominated diets were differentiated. The discriminant scores from Australian sea lions that foraged inshore indicated a mixed fish and shark diet, whereas discriminant scores from Australian sea lions that foraged offshore indicated a fish-dominated diet, although results must be interpreted with caution due to the assumptions associated with the prey FA dataset. FA analysis in combination with satellite tracking proved to be a powerful tool for assessing broad-scale spatial dietary patterns.

Status of Australian sea lions, Neophoca cinerea, and New Zealand fur seals, Arctocephalus forsteri, on Eyre Peninsula and the far west coast of South Australia

2005 ◽  
Vol 32 (1) ◽  
pp. 85 ◽  
Author(s):  
P. D. Shaughnessy ◽  
T. E. Dennis ◽  
P. G. Seager
Keyword(s):  
New Zealand ◽  
West Coast ◽  
South Australia ◽  
Sea Lion ◽  
The West ◽  
Sea Lions ◽  
Neophoca Cinerea ◽  
Fur Seals ◽  
Fur Seal ◽  
New Zealand Fur Seal

Two seal species breed on the west coast of South Australia, the Australian sea lion, Neophoca cinerea, and the New Zealand fur seal, Arctocephalus forsteri. Aerial surveys were conducted at intervals of ~3 months between April 1995 and June 1997 to determine the breeding status of sea lions and timing of pupping seasons. Ground surveys between October 1994 and April 2004 aimed at counting sea lions and fur seals, particularly pups. In all, 27 sites were examined. Six new sea lion breeding colonies were documented, at Four Hummocks, Price, North Rocky, Dorothee, West Waldegrave and Nicolas Baudin Islands. All were found or confirmed by ground survey. Pup numbers were equivalent to 12% of the total number of pups estimated in surveys conducted from 1987 to 1992, but primarily in 1990. The sighting of brown pups on aerial surveys of Ward Island, Middle and Western Nuyts Reef supports earlier indications, based on dead pups, that they are breeding colonies. The timing of pupping seasons is not synchronous; estimates are presented for colonies between 1995 and early in 2004, with predictions to the end of 2005. The abundance estimates of sea lion pups highlight the importance of visiting a colony early in the pupping season to determine when pupping begins and ~5 months later when the maximum number of pups is expected. For the New Zealand fur seal, small numbers of pups were recorded at Dorothee, West Waldegrave and Nicolas Baudin Islands, and at Nuyts Reef. These and the previously unknown sea lion breeding colonies on the west coast of South Australia suggest that further colonies may remain to be documented. Because planning for aquaculture ventures is active in South Australia, it is important that the localities and status of sea lion and fur seal colonies be established unequivocally to ensure that the need for Prohibited Area status for islands with breeding colonies and for Marine Protected Areas around them is noted.

Proximate Composition of Australian Sea Lion Milk Throughout the Entire Supra-Annual Lactation Period

1996 ◽  
Vol 44 (6) ◽  
pp. 651 ◽  
Author(s):  
NJ Gales ◽  
DP Costa ◽  
M Kretzmann
Keyword(s):  
Proximate Composition ◽  
Milk Fat ◽  
Energy Content ◽  
Lactation Period ◽  
Sea Lion ◽  
Sea Lions ◽  
Milk Samples ◽  
Neophoca Cinerea ◽  
Australian Sea Lion ◽  
Significant Difference

A total of 87 milk samples was collected from 47 Australian sea lions, Neophoca cinerea, with pups ranging from one day old to 471 days old. Analysis of proximate composition yielded an overall mean (+/- s.d.) of 30.82 +/- 9.84% lipid, 56.97 +/- 9.96% water, 9.97 +/- 2.52% protein, and 0.88 +/- 0.25% ash. Milk fat content increased during lactation and was inversely proportional to water content. There was a significant difference between the lipid content of milk collected during the first half of lactation (<250 days, range 1-120 days) (26.1 +/- 8.7%, n = 35) and that collected during the second half of lactation (>250 days, range 314-469 days) (39.1 +/- 5.5%, n = 12) (Mann-Whitney U-test, P < 0.0001). The relatively low lipid (energy) content of Australian sea lion milk is postulated to be, in part, an adaptive response to living in a low-energy marine environment where the rate of energy transfer from mother to young is decreased and the duration of maternal dependence of the young is increased.

Pup numbers of the Australian sea lion (Neophoca cinerea) at The Pages Islands, South Australia, over two decades

2013 ◽  
Vol 61 (2) ◽  
pp. 112 ◽  
Author(s):  
Peter D. Shaughnessy ◽  
Simon D. Goldsworthy ◽  
Paul Burch ◽  
Terry E. Dennis
Keyword(s):  
Population Size ◽  
South Australia ◽  
Sea Lion ◽  
Breeding Colony ◽  
Sea Lions ◽  
Neophoca Cinerea ◽  
Australian Sea Lion ◽  
Gill Net ◽  
Low Levels ◽  
Breeding Seasons

The Australian sea lion is an Australian endemic, restricted to South Australia and Western Australia, with 86% of the population in South Australia. It was listed under the Commonwealth Environment Protection and Biodiversity Conservation Act as Vulnerable in February 2005, and the International Union for the Conservation of Nature has listed it as Endangered. Sea lions are taken as bycatch in the gill-net fishery for school shark and gummy shark, and the risk of extinction of breeding colonies is high even from low levels of bycatch. We assessed trends in pup population size at The Pages Islands, a large breeding colony in South Australia. Pup abundance was estimated by direct counting of live and dead pups; the maximum count in each breeding season was used for trend analysis. The average of direct counts of pups in 14 breeding seasons between 1989–90 and 2009–10 was 473 (s.d. = 58.4). There was no trend in pup numbers, contrasting with two other large colonies: Seal Bay, Kangaroo Island (decreasing), and Dangerous Reef (increasing since 2000). The Australian Sea Lion Management Strategy of the Australian Fisheries Management Authority aims to reduce sea lion bycatch in the shark fishery; a key item is a fishery closure around each breeding colony in South Australia. Implementation of the closure around The Pages should lower the risk of bycatch of its sea lions with foraging areas that previously overlapped with the fishery and should allow the colony’s population size to increase.

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