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Tracey L Rogers - One of the best experts on this subject based on the ideXlab platform.
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food caching by a marine apex predator the Leopard Seal hydrurga leptonyx
Canadian Journal of Zoology, 2019Co-Authors: Douglas J Krause, Tracey L RogersAbstract:The foraging behaviors of apex predators can fundamentally alter ecosystems through cascading predator–prey interactions. Food caching is a widely studied, taxonomically diverse behavior that can m...
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examining the temporal structure and information entropy of Leopard Seal calling bouts
Journal of the Acoustical Society of America, 2016Co-Authors: John R Buck, Tracey L RogersAbstract:Leopard Seals (Hydrurga leptonyx) produce sequences of stereotyped sounds, or bouts, during their breeding season. The Seals share common sounds but combine them in individually distinctive sequences. This study examines the underlying structure of the calling bouts by estimating the information entropy of the sound sequences with three entropy estimators. The independent identically distributed (IID) model estimates entropy from the simple frequencies of each sound. The Markov model estimates entropy from the frequency of pairs of sounds. Finally, the nonparametric sliding window match length (SWML) estimator exploits a relationship between the information entropy and the average subsequence match length. A better model for a given sequence achieves a lower entropy estimate. This study analyzed the calling bouts of 35 Leopard Seals recorded during the 1992-1994 and 1997-1998 Antarctic field seasons. The decrease of entropy estimates between the IID and Markov models for all Seals analyzed confirmed the p...
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Density Can Be Misleading for Low-Density Species: Benefits of Passive Acoustic Monitoring
2016Co-Authors: Tracey L Rogers, Holger Klinck, Michaela B. Ciaglia, Colin SouthwellAbstract:Climate-induced changes may be more substantial within the marine environment, where following ecological change is logistically difficult, and typically expensive. As marine animals tend to produce stereotyped, long-range signals, they are ideal for repeatable surveying. In this study we illustrate the potential for calling rates to be used as a tool for determining habitat quality by using an Antarctic pack-ice Seal, the Leopard Seal, as a model.With an understanding of the vocal behavior of a species, their seasonal and diurnal patterns, sex and age-related differences, an underwater passive-acoustic survey conducted alongside a visual survey in an arc of 4,225 km across the Davis Sea, Eastern Antarctica, showed that while acoustic and visual surveys identified similar regions as having high densities, the acoustic surveys surprisingly identified the opposite regions as being ‘critical ’ habitats. Density surveys of species that cannot be differentiated into population classes may be misleading because overall density can be a negative indicator of habitat quality.Under special circumstances acoustics can offer enormous advantage over traditional techniques and open up monitoring to regions that are remote, difficult and expensive to work within, no longer restricting long-term community assessment to resource-wealthy communities. As climatic change affects a broad range of organisms across geographic boundaries we propose that capitalizing on the significant advances in passive acoustic technology, alongside physical acoustics and populatio
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vertical fatty acid composition in the blubber of Leopard Seals and the implications for dietary analysis
Journal of Experimental Marine Biology and Ecology, 2016Co-Authors: A I Guerrero, M E I Marquez, Jorge A Mennucci, K. Zaman, Javier Negrete, Tracey L RogersAbstract:Abstract The analysis of blubber fatty acids (FAs) is a useful tool to infer diet of mammals that live in remote regions where year-round studies are difficult. The FA may not be distributed uniformly within the blubber, which can have implications for dietary predictive studies. The aim of this study was to determine the FA composition in the blubber core of the Antarctic Leopard Seal, Hydrurga leptonyx, and evaluate the potential implications of FA stratification for dietary analysis. The blubber cores of 24 Seals were sub-sectioned into outer, middle and inner layers and their FA were compared to those of their potential prey species. A vertical variation in FA composition was found across the whole blubber core of the Leopard Seal. 17 FAs were found at greater than trace amounts (> 0.5%) across all samples and the most abundant were: C18:1ω9, C16:1, C22:6ω3, C16:0 and C18:1ω7, which accounted for approximately 70% of the total FA. Almost all FAs had a continuous gradient through the blubber. Principal Component Analysis confirmed separation between inner and outer layers while the middle layer was a transition. The stratification of the Leopard Seal blubber was similar to the general pattern observed in a variety of marine species: monounsaturated FA (MUFA) dominated the three layers being more abundant in the outer layer, polyunsaturated (PUFA) and saturated FA (SFA) were more abundant in the inner layer. Polyunsaturated FAs are of dietary origin and SFAs are chemically inert so they can be used as a long-term reserve, which suggest that the inner layer is the site of deposition of the FA obtained from diet. The influence of prey on the composition of the Leopard Seals' blubber was clearer in the inner layer, although neither outer nor inner layers exactly matched the FA of the potential prey. This suggests that there are other components influencing the FA composition of this predator; therefore, in order to carry out dietary analysis it is important to consider the stratification of blubber and to use the inner layer, where the influence of diet is more evident. This has significant implications for sampling methods in the field.
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source levels of the underwater calls of a male Leopard Seal
Journal of the Acoustical Society of America, 2014Co-Authors: Tracey L RogersAbstract:Leopard Seals (Hydrurga leptonyx) are top predators in the Antarctic ecosystem. They produce stereotyped calls as part of a stylized underwater vocal display. Understanding of their acoustic behavior is improved by identifying the amplitude of their calls. The amplitude of five types of calls (n = 50) from a single male Seal were measured as broadband source levels and ranged from 153 to 177 dB re 1 μPa at 1 m. The mean source levels differed between call types, the lower frequency calls (L, D, and O) tended to have source levels 10 dB higher than the higher frequency calls (H and M). Information on call-type source levels is important to take into account for passive acoustic studies investigating repertoire usage as calls produced with greater amplitudes are likely to have larger acoustic ranges, especially when these are also the calls with lower frequencies, such as is the case in Leopard Seals.
Peter L Boveng - One of the best experts on this subject based on the ideXlab platform.
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Uncommon or cryptic? Challenges in estimating Leopard Seal abundance by conventional but state-of-the-art methods
Deep Sea Research Part I: Oceanographic Research Papers, 2008Co-Authors: Colin Southwell, Tracey L Rogers, Peter L Boveng, Charles G. M. Paxton, David L. Borchers, William K. De La MareAbstract:Abstract The method traditionally used to estimate pack-ice Seal abundance employs sighting surveys from ships or aircraft to estimate the number of Seals hauled out on the ice, combined with studies of haul-out behaviour to estimate the proportion of time spent on the ice. Application of this approach has been improved in recent times by developments in survey methodology and satellite technology that theoretically allow biases in the estimation of hauled-out abundance and haul-out behaviour to be accounted for that previously could not be addressed. A survey using these conventional but state-of-the-art methods was undertaken in the summer of 1999/2000 off east Antarctica between longitudes 64°E and 150°E to estimate the abundance of Leopard ( Hydrurga leptonyx ) and other pack-ice Seal species. Because they are either uncommon or very cryptic, very few Leopard Seals were encountered despite a large survey effort. This presented challenges in both application of the methods and analysis of the data. Abundance estimates were derived using a number of plausible predictive models. The model considered as the most reliable returned best estimates of 7300 and 12,100 for definite and definite plus probable Leopard Seal sightings, respectively, with 95% confidence intervals of 3700–14,500 and 7100–23,400. These estimates are likely to be negatively biased and should be treated as minimum estimates only.
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hunting and social behaviour of Leopard Seals hydrurga leptonyx at Seal island south shetland islands antarctica
Journal of Zoology, 1999Co-Authors: Lisa M Hiruki, Michael K Schwartz, Peter L BovengAbstract:The hunting behaviour of Leopard Seals Hydrurga leptonyx was monitored opportunistically at Seal Island, South Shetland Islands, during the austral summers from 1986/87 to 1994/95. Leopard Seals used several methods to catch Antarctic fur Seal pups Arctocephalus gazella and chinstrap penguins Pygoscelis antarctica, and individuals showed different hunting styles and hunting success. One to two Leopard Seals per year were responsible for an average of 60% of observed captures of fur Seal pups. Leopard Seals preyed on penguins throughout the summer, but preyed on fur Seal pups only between late December and mid-February. Hunting behaviour differed significantly between different locations on the island; fur Seals were hunted only at one colony, and penguins were hunted in several areas. The relative abundance of prey types, size of prey in relation to predator, and specialization of individual Leopard Seals to hunt fur Seal prey probably influence individual prey preferences among Leopard Seals. On five occasions, two Leopard Seals were seen together on Seal Island. Possible interpretations of the relationship between the inter-acting Leopard Seals included a mother–offspring relationship, a consorting male–female pair, and an adult Leopard Seal followed by an unrelated juvenile. In two incidents at Seal Island, two Leopard Seals were observed interacting while hunting: one Seal captured fur Seal pups and appeared to release them to the other Seal. Observations of Leopard Seals interacting during hunting sessions were difficult to confirm as co-operative hunting, but they strongly implied that the two Seals were not agonistic toward one another. The hunting success of individual Leopard Seals pursuing penguins or fur Seals is probably high enough for co-operative hunting not to become a common hunting strategy; however, it may occur infrequently when it increases the hunting productivity of the Seals.
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population growth of antarctic fur Seals limitation by a top predator the Leopard Seal
Ecology, 1998Co-Authors: Peter L Boveng, Lisa M Hiruki, Michael K Schwartz, John L BengtsonAbstract:Antarctic fur Seals (Arctocephalus gazella) in the South Shetland Islands are recovering from 19th-century exploitation more slowly than the main population at South Georgia. To document demographic changes associated with the recovery in the South Shetlands, we monitored fur Seal abundance and reproduction in the vicinity of Elephant Island during austral summers from 1986/1987 through 1994/1995. Total births, mean and variance of birth dates, and average daily mortality rates were estimated from daily live pup counts at North Cove (NC) and North Annex (NA) colonies on Seal Island. Sightings of Leopard Seals (Hydrurga leptonyx) and incidents of Leopard Seal predation on fur Seal pups were recorded opportunistically during daily fur Seal research at both sites. High mortality of fur Seal pups, attributed to predation by Leopard Seals frequently observed at NC, caused pup numbers to decline rapidly between January and March (i.e., prior to weaning) each year and probably caused a long-term decline in the size of that colony. The NA colony, where Leopard Seals were never observed, increased in size during the study. Pup mortality from causes other than Leopard Seal predation appeared to be similar at the two sites. The number of pups counted at four locations in the Elephant Island vicinity increased slowly, at an annual rate of 3.8%, compared to rates as high as 11% at other locations in the South Shetland Islands. Several lines of circumstantial evidence are con- sistent with the hypothesis that Leopard Seal predators limit the growth of the fur Seal population in the Elephant Island area and perhaps in the broader population in the South Shetland Islands. The sustained growth of this fur Seal population over many decades rules out certain predator-prey models, allowing inference about the interaction between Leopard Seals and fur Seals even though it is less thoroughly studied than predator-prey systems of terrestrial vertebrates of the northern hemisphere. Top-down forces should be included in hypotheses for future research on the factors shaping the recovery of the fur Seal population in the South Shetland Islands.
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leptonyx) at Seal Island, South Shetland Islands, Antarctica
1998Co-Authors: South Shetl, Peter L Boveng, Lisa M Hiruki, Michael K SchwartzAbstract:Hunting and social behaviour of Leopard Seal
Rachael Gray - One of the best experts on this subject based on the ideXlab platform.
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health assessment of the Leopard Seal hydrurga leptonyx in prydz bay eastern antarctica and nsw australia
2009Co-Authors: Rachael Gray, Tracey L Rogers, P J CanfieldAbstract:The Leopard Seal Hydrurga leptonyx is the most widely distributed of the Antarctic pinnipeds, ranging from the Antarctic coastline to the sub-Antarctic (Bonner 1994) and less frequently, temperate and sub-tropical areas, including the Australian coast. The main population of Leopard Seals remains within the circumpolar pack-ice (Bonner 1994) however, there is some north–south movement of individuals, the majority of which are immature, non-breeding Seals (Gwynn 1953; Brown 1957; Csordas 1963; King 1983; Rounsevell and Eberhard 1980; Rounsevell 1988; Walker et al. 1998). A periodicity in peak abundance has been observed for this northward dispersal and it is suggested that this could be related to cyclic climatic variation within the region (Harris et al. 1988; Testa et al. 1991; Croxall 1992).
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trace element analysis in the serum and hair of antarctic Leopard Seal hydrurga leptonyx and weddell Seal leptonychotes weddellii
Science of The Total Environment, 2008Co-Authors: Rachael Gray, P J Canfield, Tracey L RogersAbstract:Leopard Seal, Hydrurga leptonyx, and Weddell Seal, Leptonychotes weddellii, occupy an upper trophic level within the Antarctic ecosystem and are useful indicator species in the Southern Ocean of trace element concentrations. Reference values for the concentration of 19 trace elements were determined in the serum and hair of Leopard and Weddell Seals sampled in Eastern Antarctica. These reference values can be used as 'baseline' levels for monitoring trace element concentrations in these species. Greater trace element concentrations were determined in hair compared to serum, indicating different time scales of trace element accumulation in these samples. For the majority of trace elements, except for Se in the Leopard Seal samples and Cr in the Weddell Seal samples, significant regression relationships for trace element concentrations in hair and serum were not elucidated. Significant differences were determined in the concentrations of seven out of 15 elements with hair type, moult and new, in the Leopard Seal; concentrations in moult hair were determined to be greater than in new hair for all elements except Zn. Hair analysis was determined to be useful for monitoring exposure to trace elements and when collected off the ice from moulting Seals, hair can be employed as a non-invasive sample for trace element analysis in Leopard and Weddell Seals.
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trace element analysis in the serum and hair of antarctic Leopard Seal hydrurga leptonyx and weddell Seal leptonychotes weddellii
Science of The Total Environment, 2008Co-Authors: Rachael Gray, P J Canfield, Tracey L RogersAbstract:Leopard Seal, Hydrurga leptonyx, and Weddell Seal, Leptonychotes weddellii, occupy an upper trophic level within the Antarctic ecosystem and are useful indicator species in the Southern Ocean of trace element concentrations. Reference values for the concentration of 19 trace elements were determined in the serum and hair of Leopard and Weddell Seals sampled in Eastern Antarctica. These reference values can be used as 'baseline' levels for monitoring trace element concentrations in these species. Greater trace element concentrations were determined in hair compared to serum, indicating different time scales of trace element accumulation in these samples. For the majority of trace elements, except for Se in the Leopard Seal samples and Cr in the Weddell Seal samples, significant regression relationships for trace element concentrations in hair and serum were not elucidated. Significant differences were determined in the concentrations of seven out of 15 elements with hair type, moult and new, in the Leopard Seal; concentrations in moult hair were determined to be greater than in new hair for all elements except Zn. Hair analysis was determined to be useful for monitoring exposure to trace elements and when collected off the ice from moulting Seals, hair can be employed as a non-invasive sample for trace element analysis in Leopard and Weddell Seals.
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histology of selected tissues of the Leopard Seal and implications for functional adaptations to an aquatic lifestyle
Journal of Anatomy, 2006Co-Authors: Rachael Gray, P J Canfield, Tracey L RogersAbstract:The microscopic anatomy of the cardio-respiratory system, digestive system, kidney, lymphatic system and integument was investigated in the Leopard Seal, Hydrurga leptonyx, by examining histological sections of tissues collected from Leopard Seals in Antarctica and New South Wales, Australia. The majority of the tissues had similar histological features to those described in terrestrial mammals and other pinniped species, particularly phocid Seals. Differences noted included readily identifiable Purkinje cells within the endocardium, muscular rather than cartilaginous reinforcement of the smaller airways, a single capillary layer within the alveolar septa, limited and variable keratinization of the oesophageal epithelium, few lymphoid follicles within the lamina propria of the gastrointestinal tract, and an absence of a sporta perimedullaris musculosa described in the kidney of cetaceans and some pinniped species. Adaptations of the lung, spleen and integument, similar to those described in other pinnipeds, including reinforcement of the pulmonary terminal airways, prominent pulmonary interlobular septa, ample smooth muscle in the capsule and trabeculae of the spleen, increased thickness of the epidermis, well-developed dermal sebaceous glands, and a thick blubber layer, appear to confer upon the Leopard Seal advantages related to its aquatic lifestyle.
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serum proteins in the Leopard Seal hydrurga leptonyx in prydz bay eastern antarctica and the coast of nsw australia
Comparative Biochemistry and Physiology B, 2005Co-Authors: Rachael Gray, P J Canfield, Tracey L RogersAbstract:Abstract Blood protein analysis including total serum protein and albumin by chemical methods, fibrinogen estimation and serum protein electrophoresis (SPE) was performed on the Leopard Seal, Hydrurga leptonyx . The most commonly observed SPE pattern was eight fractions designated albumin, α 1a , α 1b , α 2a , α 2b , β 1 , β 2 and γ-globulin. Significantly higher total serum protein and albumin concentrations, as determined by chemical methods, and significantly higher α 2 -globulin concentrations, determined by SPE, were seen in free-ranging male Seals compared to females, whilst significantly higher β-globulin concentrations were seen in female Seals. Season of sampling influenced fibrinogen and β 2 -globulin concentrations, whereas there were no significant differences in any protein concentrations with moult status. Qualitative comparison of SPE traces of Leopard Seals in Antarctica with “sick” individuals in NSW, Australia revealed obvious differences, as did quantitative comparison of protein concentrations where differences in α 1 , α 2 , β 1 , β 2 , and γ-globulin concentrations were seen. These findings suggest that SPE is a useful tool for investigating serum proteins in the Leopard Seal, with applications for the investigation of “sick” individuals and the assessment of variation in homeostasis. This technique could also be used to identify the presence of environmental stressors, subclinical disease and physiological variation within specific Seal populations.
Elizabeth M Deane - One of the best experts on this subject based on the ideXlab platform.
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do free ranging common brushtail possums trichosurus vulpecula play a role in the transmission of toxoplasma gondii within a zoo environment
Veterinary Parasitology, 2008Co-Authors: Nichola J Hill, Michelle L Power, J P Dubey, L Vogelnest, Elizabeth M DeaneAbstract:To investigate the possible role of common brushtail possums (Trichosurus vulpecula) in the transmission of Toxoplasma gondii within a zoo environment, a serological survey of a free-ranging population resident within Taronga Zoo, Sydney, Australia was undertaken using the modified agglutination test (MAT). For comparison, the seroprevalence of T. gondii antibodies was also assessed in a possum population inhabiting a felid-free, non-urban woodland habitat. Six of 126 possums (4.8%) from the zoo population had antibodies to T. gondii with a MAT titre of 25 or higher, while in contrast, all of the 17 possums from woodland were seronegative. These observations suggest that possums were at a higher risk of exposure to the parasite as a consequence of co-existing with domestic, stray and captive felids associated with urbanisation. Screening of captive felids at the zoo indicated 16 of 23 individuals (67%) and all 6 species were seropositive for T. gondii, implicating them as a possible source of the parasite within the zoo setting. In addition captive, non-felid carnivores including the chimpanzee (Pan troglodytes), saltwater crocodile (Crocodylus porosus), dingo (Canis lupis) and Leopard Seal (Hydrurga leptonyx) were tested for the presence of T. gondii antibodies as these species predate and are a leading cause of death amongst zoo possums. In total, 5 of 23 individuals (22%) were seropositive, representing 2 of the 4 carnivorous species; the dingo and chimpanzee. These data suggest that carnivory was not a highly efficient pathway for the transmission of T. gondii and the free-ranging possum population posed minimal threat to the health of zoo animals.
P J Canfield - One of the best experts on this subject based on the ideXlab platform.
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health assessment of the Leopard Seal hydrurga leptonyx in prydz bay eastern antarctica and nsw australia
2009Co-Authors: Rachael Gray, Tracey L Rogers, P J CanfieldAbstract:The Leopard Seal Hydrurga leptonyx is the most widely distributed of the Antarctic pinnipeds, ranging from the Antarctic coastline to the sub-Antarctic (Bonner 1994) and less frequently, temperate and sub-tropical areas, including the Australian coast. The main population of Leopard Seals remains within the circumpolar pack-ice (Bonner 1994) however, there is some north–south movement of individuals, the majority of which are immature, non-breeding Seals (Gwynn 1953; Brown 1957; Csordas 1963; King 1983; Rounsevell and Eberhard 1980; Rounsevell 1988; Walker et al. 1998). A periodicity in peak abundance has been observed for this northward dispersal and it is suggested that this could be related to cyclic climatic variation within the region (Harris et al. 1988; Testa et al. 1991; Croxall 1992).
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trace element analysis in the serum and hair of antarctic Leopard Seal hydrurga leptonyx and weddell Seal leptonychotes weddellii
Science of The Total Environment, 2008Co-Authors: Rachael Gray, P J Canfield, Tracey L RogersAbstract:Leopard Seal, Hydrurga leptonyx, and Weddell Seal, Leptonychotes weddellii, occupy an upper trophic level within the Antarctic ecosystem and are useful indicator species in the Southern Ocean of trace element concentrations. Reference values for the concentration of 19 trace elements were determined in the serum and hair of Leopard and Weddell Seals sampled in Eastern Antarctica. These reference values can be used as 'baseline' levels for monitoring trace element concentrations in these species. Greater trace element concentrations were determined in hair compared to serum, indicating different time scales of trace element accumulation in these samples. For the majority of trace elements, except for Se in the Leopard Seal samples and Cr in the Weddell Seal samples, significant regression relationships for trace element concentrations in hair and serum were not elucidated. Significant differences were determined in the concentrations of seven out of 15 elements with hair type, moult and new, in the Leopard Seal; concentrations in moult hair were determined to be greater than in new hair for all elements except Zn. Hair analysis was determined to be useful for monitoring exposure to trace elements and when collected off the ice from moulting Seals, hair can be employed as a non-invasive sample for trace element analysis in Leopard and Weddell Seals.
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trace element analysis in the serum and hair of antarctic Leopard Seal hydrurga leptonyx and weddell Seal leptonychotes weddellii
Science of The Total Environment, 2008Co-Authors: Rachael Gray, P J Canfield, Tracey L RogersAbstract:Leopard Seal, Hydrurga leptonyx, and Weddell Seal, Leptonychotes weddellii, occupy an upper trophic level within the Antarctic ecosystem and are useful indicator species in the Southern Ocean of trace element concentrations. Reference values for the concentration of 19 trace elements were determined in the serum and hair of Leopard and Weddell Seals sampled in Eastern Antarctica. These reference values can be used as 'baseline' levels for monitoring trace element concentrations in these species. Greater trace element concentrations were determined in hair compared to serum, indicating different time scales of trace element accumulation in these samples. For the majority of trace elements, except for Se in the Leopard Seal samples and Cr in the Weddell Seal samples, significant regression relationships for trace element concentrations in hair and serum were not elucidated. Significant differences were determined in the concentrations of seven out of 15 elements with hair type, moult and new, in the Leopard Seal; concentrations in moult hair were determined to be greater than in new hair for all elements except Zn. Hair analysis was determined to be useful for monitoring exposure to trace elements and when collected off the ice from moulting Seals, hair can be employed as a non-invasive sample for trace element analysis in Leopard and Weddell Seals.
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histology of selected tissues of the Leopard Seal and implications for functional adaptations to an aquatic lifestyle
Journal of Anatomy, 2006Co-Authors: Rachael Gray, P J Canfield, Tracey L RogersAbstract:The microscopic anatomy of the cardio-respiratory system, digestive system, kidney, lymphatic system and integument was investigated in the Leopard Seal, Hydrurga leptonyx, by examining histological sections of tissues collected from Leopard Seals in Antarctica and New South Wales, Australia. The majority of the tissues had similar histological features to those described in terrestrial mammals and other pinniped species, particularly phocid Seals. Differences noted included readily identifiable Purkinje cells within the endocardium, muscular rather than cartilaginous reinforcement of the smaller airways, a single capillary layer within the alveolar septa, limited and variable keratinization of the oesophageal epithelium, few lymphoid follicles within the lamina propria of the gastrointestinal tract, and an absence of a sporta perimedullaris musculosa described in the kidney of cetaceans and some pinniped species. Adaptations of the lung, spleen and integument, similar to those described in other pinnipeds, including reinforcement of the pulmonary terminal airways, prominent pulmonary interlobular septa, ample smooth muscle in the capsule and trabeculae of the spleen, increased thickness of the epidermis, well-developed dermal sebaceous glands, and a thick blubber layer, appear to confer upon the Leopard Seal advantages related to its aquatic lifestyle.
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serum proteins in the Leopard Seal hydrurga leptonyx in prydz bay eastern antarctica and the coast of nsw australia
Comparative Biochemistry and Physiology B, 2005Co-Authors: Rachael Gray, P J Canfield, Tracey L RogersAbstract:Abstract Blood protein analysis including total serum protein and albumin by chemical methods, fibrinogen estimation and serum protein electrophoresis (SPE) was performed on the Leopard Seal, Hydrurga leptonyx . The most commonly observed SPE pattern was eight fractions designated albumin, α 1a , α 1b , α 2a , α 2b , β 1 , β 2 and γ-globulin. Significantly higher total serum protein and albumin concentrations, as determined by chemical methods, and significantly higher α 2 -globulin concentrations, determined by SPE, were seen in free-ranging male Seals compared to females, whilst significantly higher β-globulin concentrations were seen in female Seals. Season of sampling influenced fibrinogen and β 2 -globulin concentrations, whereas there were no significant differences in any protein concentrations with moult status. Qualitative comparison of SPE traces of Leopard Seals in Antarctica with “sick” individuals in NSW, Australia revealed obvious differences, as did quantitative comparison of protein concentrations where differences in α 1 , α 2 , β 1 , β 2 , and γ-globulin concentrations were seen. These findings suggest that SPE is a useful tool for investigating serum proteins in the Leopard Seal, with applications for the investigation of “sick” individuals and the assessment of variation in homeostasis. This technique could also be used to identify the presence of environmental stressors, subclinical disease and physiological variation within specific Seal populations.