Estimating diet composition of the Australian sea lion (Neophoa cinerea) from scat analysis: an unrliable technique

1992 ◽  
Vol 19 (4) ◽  
pp. 447 ◽  
Author(s):  
NJ Gales ◽  
AJ Cheal
Keyword(s):  
Qualitative Description ◽  
Sea Lion ◽  
Sea Lions ◽  
Neophoca Cinerea ◽  
Australian Sea Lion ◽  
Complete Digestion ◽  
Feeding Trials ◽  
Panulirus Cygnus ◽  
In Transit ◽  
Free Ranging

Knowledge of the diet of the Australian sea-lion (Neophoca cinerea) has been restricted to anecdotal, qualitative accounts. In this study, we tested the validity of using identifiable prey remains in scats to quantify the diet of N. cinerea by analysis of scats from free-ranging sea-lions and feeding trials on captive sea-lions. Identifiable remains in the scats of free-ranging animals occurred infrequently: otoliths (n = 8) were present in only 9% of scats, cephalopod beaks (n = 23) in only 24% and lobster (Panulirus cygnus) remains in 7%. These limited data, combined with analysis of contents of five stomachs, indicated that N. cinerea has a broad diet and feeds on some benthic species. Feeding trials on two captive sea-lions demonstrated that scats were not representative of the diet. Fewer than 2% of ingested otoliths (by number) were recovered in scats. Otoliths less than 5 mm long were absent from scats; recovery of larger otoliths increased with their size. Defaecated otoliths were eroded by at least 28% (by length) during digestion. Transit of cephalopod mouth parts in two captive animals was variable (98% and 9% recovery), with only beaks of small cephalopods passing through the pyloric canal. The complete digestion of otoliths in transit through the gut tract and the variable recovery of cephalopod beaks indicated that scats cannot be used even for a qualitative description of the diet of N. cinerea.

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.

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.

scholarly journals Social olfaction in marine mammals: wild female Australian sea lions can identify their pup's scent

2010 ◽  
Vol 7 (1) ◽  
pp. 60-62 ◽  
Author(s):  
Benjamin J. Pitcher ◽  
Robert G. Harcourt ◽  
Benoist Schaal ◽  
Isabelle Charrier
Keyword(s):  
Marine Mammals ◽  
Social Contexts ◽  
Social Recognition ◽  
Wild Female ◽  
Sea Lions ◽  
Neophoca Cinerea ◽  
Australian Sea Lion ◽  
The Social ◽  
Free Ranging ◽  
Anatomical Evidence

Historically, anatomical evidence has suggested that marine mammals are anosmic or at best microsmatic, i.e. absent or reduced olfactory capabilities. However, these neuroanatomical considerations may not be appropriate predictors for the use of olfaction in social interactions. Observations suggest that pinnipeds may use olfaction in mother–pup interactions, accepting or rejecting pups after naso-nasal contact. Such maternal–offspring recognition is a favourable area for investigating the involvement of odours in social recognition and selectivity, as females are evolutionarily constrained to direct resources to filial young. However, there is no experimental, morphological or chemical evidence to date for the use of olfaction in social contexts and for individual odour recognition abilities in pinnipeds. Here, we report unequivocal evidence that Australian sea lion ( Neophoca cinerea ) females can differentiate between the odour of their own pup and that of another, in the absence of any other distinguishing cues. This study demonstrates individual olfactory recognition in a free-ranging wild mammal and is clear evidence of the social function of olfaction in a marine mammal.

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.

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.

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