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

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.

2016 ◽  
Vol 82 (12) ◽  
pp. 3440-3449 ◽  
Author(s):  
Tiffany C. Delport ◽  
Michelle L. Power ◽  
Robert G. Harcourt ◽  
Koa N. Webster ◽  
Sasha G. Tetu

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.


1992 ◽  
Vol 19 (4) ◽  
pp. 447 ◽  
Author(s):  
NJ Gales ◽  
AJ Cheal

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.


2007 ◽  
Vol 29 (1) ◽  
pp. 103 ◽  
Author(s):  
R.R. McIntosh ◽  
M.D. Murray

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


1991 ◽  
Vol 69 (10) ◽  
pp. 2556-2561 ◽  
Author(s):  
Maria B. Kretzmann ◽  
Daniel P. Costa ◽  
Lesley V. Higgins ◽  
D. J. Needham

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.


1999 ◽  
Vol 47 (2) ◽  
pp. 193 ◽  
Author(s):  
B. Bodley ◽  
the late J. R. Mercer ◽  
M. M. Bryden

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.


2006 ◽  
Vol 33 (8) ◽  
pp. 661 ◽  
Author(s):  
Rebecca R. McIntosh ◽  
Brad Page ◽  
Simon D. Goldsworthy

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.


2009 ◽  
Vol 36 (2) ◽  
pp. 169 ◽  
Author(s):  
A. M. M. Baylis ◽  
D. J. Hamer ◽  
P. D. Nichols

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.


2019 ◽  
Vol 76 (10) ◽  
pp. 1854-1861
Author(s):  
Aurélien Vivancos ◽  
Gerry Closs

Key aspects of the social behaviour of groups of drift-feeding fish can be inferred by the way space is shared between group members, because they inhabit a very dynamic and complex environment where spatial positions have a direct impact on fitness-related traits. Therefore, the spatial analysis of such a system can reveal important insights into behavioural ecology of fish, but so far, technical constraints limited this approach to only large salmonids. We used a digital imaging technique to monitor movements and behaviour of free-ranging groups of juvenile galaxiids (Galaxias anomalus) facing two contrasting physical and social contexts. We described the spatial structure of these groups and studied individual space use in relation to their social behaviour. We found that prevalence of territorial behaviour differs greatly between sites, which suggests that groups were displaying different social organisation. This study showed that detailed spatial analysis of space use and behaviour of drift-feeding fish could provide new insights into the social organisation of group-living animals.


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